contents · cis-[ptcl,(nh 3)2 1, and cis-tetrachloro- diammineplatinum(iv), cis-[ptcl,(nh,),i, as...

UK ISSN 0032-1400

PLATINUM METALS REVIEW

A quarterly survey of research on the platinum metals and of developments in their application in industry

VOL. 33 OCTOBER 1989

Contents

Platinum Anti-Cancer Agents

New Acetyls Complex Commissioned at Hull

The Grove Fuel Cell Symposium

Thermomagneto-Optical Recording Materials

Towards a Cleaner Environment

Monitoring Combustible Gases

Ruthenium and Osmium 0 x 0 Complexes as Organic Oxidants

Palladium Impedes Radionuclide Pick-Up in Steel

An Advantageous Use of Palladium Compounds in Organic Synthesis

Palladium as an Aid in Trace Analysis of Food

Plasma-Enhanced Vapour Deposition of Thin Rhodium Films

Controlling Motor Vehicle Emissions

The New European Emissions Standards

Abstracts

New Patents

Index to Volume 33

NO. 4

I 62

I 68

16 9

177

178

I 80

181

185

I 86

193

193

194

212

213

224

232

Communications should be addressed to The Editor, Platinum Metals Review

Johnson Matthey Public Limited Company, Hatton Garden, London ECl N 8EE

Platinum Anti-Cancer Agents TWENTY YEARS OF CONTINUING DEVELOPMENT

By C. F. J. Barnard Johnson Matthey Technology Centre

It is now 20 years since the publication of the anti-tumour activity of platinum compounds by Barnett Rosenberg and his colleagues. During this time platinurn-based drugs have made a major contribution to cancer therapy with significant benefits for many patients. This article sum- marises the history of platinum agents in this field and indicates the current and possible future directions of research.

It was in 1962 that an apparently unrelated experiment in cell division provided the stimulus for the investigation of the potential of platinum complexes as anti-tumour agents. Barnett Rosenberg, the then recently appointed Professor of Biophysics at Michigan State University, U.S.A., was investigating the effect of electromagnetic fields on the division process for cells of higher organisms (eukaryotic cells). However, while testing his apparatus on the less organised cells of the bacterium Escherichia Coli (prokaryotic cells) he noted the formation of giant filaments containing un- divided bacterial cells. It was not until three years later that he was able to publish his results, having finally concluded that the effect was due to dissolution of tiny amounts of platinum from the electrodes, followed by reaction with chloride and ammonium ions in the growth medium to generate compounds which could inhibit cell division. The relationship between this effect and potential anti-cancer activity was not appreciated immediately, and it was a further four years later, in 1969, that the initial anti-tumour screening results were published in the journal Nature. This work identified cis-dichlorodiammineplatinum(II), cis-[PtCl,(NH 3)2 1, and cis-tetrachloro- diammineplatinum(IV), cis-[PtCl,(NH,),I, as highly potent agents in murine tumour screens. Further anti-tumour screening was provided by the National Cancer Institute of America leading to the selection of the platinum(I1) compound (cisplatin, NSC

119875, as shown in Figure I opposite) for preclinical evaluation. Despite evidence of a broad range of toxic effects clinical trials were initiated in 1971. During this period cisplatin was also evaluated by the Institute of Cancer Research in the U. K. leading to clinical trials at the Royal Marsden Hospital in London.

Clinical trials of Cisplatin The early trials confirmed that cisplatin

therapy was associated with a number of side effects. The most significant were kidney toxicity and severe nausea and vomiting. Addi- tionally, neuropathy and hearing loss were observed in some patients. Importantly, the kidney toxicity was found to be cumulative when multiple doses were given as a course of treatment. Thus, while encouraging responses were noted in patients with some tumour types, particularly those of genito-u-rinary origin, the toxicity of the treatment discouraged doctors from conducting clinical trials, and in 1973 doubts were expressed as to whether cisplatin would find a place in cancer therapy. However, some spectacular results on testicular cancer, when cisplatin was used in combination with other drugs, kept interest alive.

Between 1973 and 1977, in the majority of clinical trials cisplatin was used in low doses (20-30 mg/m2, milligrams of drug per square metre of body surface area), either as a single agent or in combination therapy, to minimise kidney toxicity. A major breakthrough occurred in 1977 with the development of the

Platinum Metah Rev., 1989, 33, (4), 162-167 162

Fig. 1 while that on the right is the second generation analogue Carboplatin

Liceneed platinum druge; the etructure on the left is that of Cisplatin, NSC 119875, I technique of giving cisplatin with pre- and post- hydration and mannitol-induced diuresis. This minimised the concentration of cisplatin in the kidneys and allowed doses up to 120 mglm’ to be given with tolerable kidney toxicity. The significant therapeutic benefits of cisplatin could then be more fully realised. For testicular cancer, prior to the use of cisplatin, complete remission rates had been increased to 36 per cent by the use of combination chemotherapy. With the inclusion of cisplatin response rates were increased to essentially 100 per cent, with approximately 70 per cent complete remissions, and today over y~ per cent long term remissions are achieved. Cisplatin therapy also achieved major improvements in response rates for ovarian cancer and recurrent or metastatic head and neck tumours. In both these latter cases, however, remissions are often of limited duration.

Marketing Approval Granted Cisplatin was licensed from Research Cor-

poration, representing Michigan State Univer- sity, by Bristol-Myers, and in 1978 marketing approval was obtained in the U.S.A. for its sale under the tradename Platinol, followed closely by approval in the U.K. in March 1979. Licences in numerous other countries followed and Platinol sales are now in excess of $100 million per year. Further clinical trials over the past 10 years have extended its use, such that it is now probably the most widely used anti- cancer drug. In addition to genito-urinary disease (testicular, ovarian, cervix, bladder) and head and neck cancer for which cisplatin was originally licensed, it is now one of the

drugs used in the chemotherapy of lung cancers, both small cell and non-small cell types; 75 and 25 per cent, respectively, of patients receiving some chemotherapy. Regrettably, responses to chemotherapy are often of short duration for these tumours. Recent reports of clinical trials using single agent cisplatin in the treatment of metastatic breast cancer suggest that it may also in the future achieve a role in the management of this disease.

In vitro and in vivo studies have suggested a significant dose-response relationship for cisplatin, encouraging clinicians to seek means of safely administering higher doses. Ad- ministration in hypertonic (3 per cent) saline has been used to deliver zoo mg/m2 cisplatin (as 40 mg/m2 each day for five days) with tolerable kidney toxicity, but under these circumstances the neurotoxicity is not relieved, reducing the benefit of th is approach. Protec- tive or rescue therapy involving the administration of sulphur-containing compounds, for example diethyldithiocarbamate (DDTC) or thiosulphate, to counter cisplatin toxicities is also being investigated. Trials in this area are complicated by the need to establish both the appropriate dose and the scheduling of the counter-agent relative to cisplatin in order to obtain protective action, while not diminishing the anti-tumour activity. This approach has been most successful when cisplatin has been given intra-arterially or intraperitoneally to achieve locally high concentrations, with the counter-agent being delivered intravenously.

Another factor limiting patient compliance with high dose cisplatin is the severe gastrointestinal disturbance that is commonly

Platinum Metals Rev., 1989, 33, (4) 163

experienced. Anti-emetic drugs such as metoclopramide have been used to moderate t h i s effect with limited success. Recently, however, a number of new anti-emetic drugs (5-HT3 antagonists) have entered clinical trials and seem to offer the prospect of enhanced anti- emetic effects with reduced side effects compared with metoclopramide.

Structure-Activity Studies of Platinum Compounds

The evaluation of other platinum complexes as anti-tumour agents has taken place since 1970. Early work at Michigan State University established the range of compounds possessing anti-tumour activity. More detailed work on structure-activity correlations was carried out in the U.K. with support from Johnson Mat- they and Rustenburg Platinum Mines, principally involving synthetic chemists at University College, London, and the screening facilities of the Institute of Cancer Research. The major achievement of this programme was to define a structure toxicity relationship based on the leaving ability of the anionic ligands, rather than identifying improved activity relative to cisplatin. More stable compounds, for example those containing bidentate malonate ligands, are less toxic than reactive compounds, such as those containing nitrate or sulphate ligands. Prior to the licensing of cisplatin to Bristol-Myers a number of other platinum complexes were unsuccessfully tested by clinics and academic institutes in attempts to select an alternative compound with similar activity but reduced toxicity. Following the launch of cisplatin, Bristol-Myers in conjunction with Johnson Matthey and the Institute of Cancer Research took up this challenge. Using the experience gained during the structure- activity studies in the early I97OS, in combination with the results of Bristol-Myers in-house screening, diammine( I , I-cyclobutanedicarb- oxylato)platinum(II) (JM-8, carboplatin, as shown in Figure I on previous page) was selected as a promising candidate. The activity of this compound against a human lung tumour implanted in immune-deprived mice (a

xenograft) was a key feature in the decision of the Institute of Cancer Research to propose its evaluation in clinical trials. These trials, supported by Bristol-Myers, were initiated in 1981 at the Royal Marsden Hospital. The results, in agreement with the preclinical evaluation, showed carboplatin to have little kidney toxicity and neurotoxicity, with reduced nausea and vomiting when compared with cisplatin. The dose limiting factor was toxicity to the bone marrow, causing a reduction in the number of platelets (thrombocytopoenia) and white blood cells (leucopoenia). This was a reversible effect with cell levels recovering over 4 to 6 weeks. These results were later confrmed in many other hospitals in trials evaluating a variety of dose schedules.

Clinical Trials and Marketing Approval of Carboplatin

Clinical trials at the Royal Marsden Hospital continued in the early 198os, with a comparison of the effectiveness of carboplatin and cisplatin in the treatment of ovarian cancer. The response rate and long term survival rates indicated equivalence in activity between the two drugs, with carboplatin offering a reduced spectrum of toxicity. Carboplatin was also found to be a highly active drug for the treatment of small cell lung cancer, though as noted above for cisplatin-containing chemotherapy, the responses were of short duration. These results, confirmed by other trials in Europe and the U.S.A., prompted Bristol-Myers to seek approvals for the marketing of carboplatin. A product licence was granted in the U.K. in March 1986, in the majority of other European countries in the period 1986-88, and most recently in the U.S.A.

As for cisplatin, evidence of a dose-response relationship was obtained in clinical trials encouraging investigations of hlgh dose schedules. In these studies employing doses up to 1600 mg/m2, four times greater than the “normal” dose, the range of toxic effects was little changed from that previously observed, with severe haematological toxicity being countered by platelet transfusions and


autologous bone marrow transplantation when necessary. The majority of these trials involved treatment of tumours refractory to other drugs, often including cisplatin, and though response rates were not high, the results for ovarian cancer and acute leukaemia were suMiciently encouraging for these trials to continue. Im- proved techniques for mitigating the haematological toxicity of high dose chemotherapy are being developed, and one of the most promising is the administration, with or without autologous bone marrow transplantation, of growth factors for bone marrow cells, stimulating the production of certain white blood cells. These growth factors are now more widely available through recombinant DNA production techniques, and the results of clinical trials in combination with carboplatin are awaited with interest.

The activity of carboplatin has been found to be similar to that of cisplatin in a number of other tumour types, for example testicular, head and neck, non-small cell lung and bladder cancer, with probably somewhat less activity in cervical cancer. The results of trials on a number of other tumours are given in the Table. Response rates for lymphomas and breast cancers are significantly higher for patients who have not received prior chemotherapy.

When compared with cisplatin therapy, the reduced emesis associated with carboplatin and the avoidance of hydration techniques provides a significant improvement in the quality of life for patients undergoing treatment. While cost

Clinical Trials of Carboplatin

Type of tumour

Lymphoma Breast Melanoma Stomach Esophagus Colonhectum Paediatric - brain Paediatric -other

solid tumours

Number of trials

Response, per cent

27 10 10 6 4 2

22 6

advantages may lead to the continued use of cisplatin in the first line treatment of testicular and ovarian cancer, the greater ease with which carboplatin can be used in high dose schedules suggests that it will substitute for cisplatin in the treatment of advanced or refractory disease. Also the absence of kidney and neurotoxic com- plications makes carboplatin a suitable agent for use in the palliative treatment of cancer, for example lung tumours.

Of relevance to the use of carboplatin in refractory tumours is the degree of cross- resistance with cisplatin. Clinically this has been found to be high, though occasionally responses are seen to carboplatin for disease resistant to cisplatin. This is believed tb result from pharmacokinetic differences since studies indicate the same mechanism of action for the two drugs. This mechanism is thought to involve platinum binding to DNA. Analysis of

C l Fig. 2 Platinum complexes containing the ligand 1,2-&aminocyclohexane, currently in clinical development; Tetraplatin (Upjohn) i e shown on the lefi and Oxsliplatin (Rhone- I Poulenc) is shown on the right

Platinum Metak Rev., 1989, 33, (4) 165

Clinical Trials of Carboplatin

1 Type of tumour Number of Response, trials per cent

Lymphoma 3 27 Breast 4 10 Melanoma 3 10 Stomach 5 6 Esophagus 2 4 Colonhectum 3 2 Paediatric - brain 2 22 Paediatric -other 2 6

solid tumours

Phase I: CL 287110 (American Cyanamid)

Pt

Phase I: CL 286558 (American Cyanamid)

//o HO

HO

'"-co Phase (Nippon Kagaku) NK-121

Pt 'Oro Phase 11: 254-S NH3\ (Shionogi)

NH 3' '0

&":; P+

Phase (Chugai) 111: DWA-2114R

Fig. 3 Platinum complexes used in clinical trials

the products of in vitro and in vivo reactions of guanine adducts have been carried out to define cisplatin with DNA has shown that binding to the structure and effect of this binding to two neighbouring or next neighbouring DNA. Interestingly, the role of the S'-phos- guanine residues is the preferentially formed phate in hydrogen bonding to one ammine adduct. Detailed NMR spectroscopy and X-ray group of cisplatin may explain the results of crystallography studies on various cisplatin- early structure-activity studies, which showed


that complexes containing primary amines were more active than those of secondary amines, while tertiary amine complexes were inert.

Other investigators of the mechanism of the action of platinum drugs have attempted to define the difference between sensitive and resistant strains of a particular cell line. Evidence has been found of differences in the level of deactivating sulphur donor ligands (for example metallothionein or glutathione) within the cell, differences in the permeability of the cell membrane, and variations in platinum concentration within the cell which may account for the differences in sensitivity. It is likely that different mechanisms are displayed by different cell types, and possible that resistance arises from a combination of mechanisms.

The Continuing Development of Platinum Compounds

Attempts to identify platinum compounds which will not be cross-resistant with cisplatin have formed a key part of many efforts to develop alternative complexes for clinical evaluation. As early as 1977, complexes containing the I ,2-diaminocyclohexane ligand were known to be effective agents against the LIZIO leukaemia cell line resistant to cisplatin. Numerous complexes containing this ligand have been evaluated in clinical trials, with the latest compounds in clinical development being oxaliplatin and tetraplatin, these being shown in Figure 2. Due to toxicity and little evidence of activity, none of these complexes has received widespread evaluation to date, so a lack of cross-resistance in the clinic has not been proven.

Many of the other complexes currently in clinical trials also contain diamine ligands for

the same reason. Another common feature of these platinum complexes is the I , I-cyclobutanedicarboxylate group which assists in providing adequate aqueous solubility for formulation while reducing toxicity compared with cisplatin, see Figure 3. It remains to be seen whether any of these compounds will have advantages over carboplatin. However, it is certain that researchers seeking new complexes for development will continue to see a lack of cross-resistance to cisplatin as a major goal. It is hoped that improvements in screening techniques through the use of human tumour xenografts will provide a better basis for assessing cross-resistance in a clinically relevant manner.

Other therapeutic goals for the further development of platinum based chemotherapy include oral delivery, a different spectrum of anti-tumour activity and improved targeting of the drugs. Targeting studies using hormonal recognition or linking to monoclonal antibodies have been carried out, and, while these programmes require many years of research, drugs with greatly improved selectivity will undoubtedly be developed.

The Future Outlook for Platinum Anti-Cancer Drugs

The early development of platinum drugs relied heavily on U.S. government support with little interest from pharmaceutical companies in a metal-based drug. The number of companies developing platinum drugs today clearly indicates that this is no longer the case. We may therefore look forward to significant advances during the next 20 years, to fulfd the potential of these agents for the benefit of cancer patients worldwide.

Bibliography B. Rosenberg, L. VanCamp, J. E. Trosko and V. H. “Platinum and Other Metal Coordination Com- Mansour, Nature, 1969, 222, 385 pounds in Cancer Chemotherapy”, ed. M. Nicolini, “Platinum Coordination Complexes in Cancer Martinus Nijhoff, Boston, 1988 Chemotherapy”, ed. T. A. Connors and J. J. pmC. Am. sot. clin. h o l . , 19g9, 8 Roberts, Springer-Verlag, New York, 1974 Biochimie, 1978, 60, (9), 835-965 “Carboplatin Workshop Abstracts”, Bristol-Myers, “Cisplatin-Current Status and New Developments”, 1989 ed. A. W. Prestayko, S. T. Crooke and S. K. Carter, I. Tarr, “Cancer Chemotherapy Report”, PJB Academic Press, New York, 1980 Publications, Richmond, England, 1989

Plotinurn Metals Rev., 1989, 33, (4) 167

New Acetyls Complex Commissioned at Hull RHODIUM COMPOUND CATALYSES KEY REACTION

Although there are no accurate data, the world demand for acetic acid is probably of the order of 10 billion pounds per year, for which the main applications are in the production of vinyl acetate, cellulose acetate, esters and terephthalic acid, which in turn find use in a wide range of manufacturing industries including adhesives, dyes, films and plastics, herbicides, inks and paints, pharmaceuticals, and textiles.

Of the three basic ways of producing acetic acid, the carbonylation of methanol is regarded as the lowest cost route when both capital costs and variable costs are considered. The share of total production accounted for by carbonylation has grown substantially over the past decade, a situation which will be consolidated by the recent completion and commissioning of a new acetyls complex for BP Chemicals Limited at Hull, England. The new plant has a capacity of 175,000 tonnes per year and is believed to be unique, in that it manufactures both acetic acid and acetic anhydride in the same reaction chamber; furthermore, by changing the reaction conditions, it is

possible to “swing” the reaction and so change the ratio of acetic acid to acetic anhydride produced. Thus the output of acetic acid can be varied between 40 and 60 per cent of total output, depending upon market requirements.

The process technology involved was developed by BP Chemicals, and is an elegant modification of the Monsanto methanol carbonylation process for acetic acid manufacture, which was fmt developed in the early 197Os, and reported here at that time (J.F. Roth, “The Production of Acetic Acid”, Platinum Metals Rev., 1975, 19, (I), 12).

A sigdkant modification made by BP Chemicals to the earlier Monsanto process involves reacting a part of the methanol feedstock with recycled acetic acid, forming methyl acetate. The latter, together with the remainder of the methanol, is then treated with carbon monoxide; this reaction being promoted by a rhodium-based liquid-phase catalyst. The use of this rhodium catalyst in the presence of an iodide promoter enables the reaction to take place at about 185Oc and 40 bar.

Platinum Metah Rev., 1989, 33, (4), 168 168

The Grove Fuel Cell Symposium POLLUTION-FREE POWER SOURCES ATTRACT WORLDWIDE INTEREST FOR STATIC AND TRANSPORT APPLICATIONS

By D. G. Lovering Consultant, Swindon, Wiltshire, England

Commemorating the one hundred and fiftieth anniversary of the first exposition of the fuel cell principle by Sir William Grove, over two hundred delegates gathered at the Royal In- stitution, London, for a four day conference, from 18th to 21st September, 1989. Twenty papers, six short contributions and three panel discussions addressed the historical context, environmental implications and national efforts for each type of fuel cell in turn. Applications for centralised and dispersed power generating plants were considered, including operation in the combined heat and power (CHP) and co- generation modes. In the transport sector, fuel cells were predicted to have an important role for road vehicles, marine vessels and in space. Phosphoric acid (PAFC), alkaline (AFC) and solid polymer (SPFC) fuel cells rely on noble metal, mainly platinum, electrocatalysts at present. The Symposium heard of the imminent availability of commercial units, suggesting that if widespread introductions could be achieved, then a considerable new market would open up for these metals and would lead to a cleaner, more efficient world.

The conference was convened by an ad hoc steering committee, drawn mainly from British industry but with academic, establishment and government support. The aims were to provide a platform for international leaders in this promising new technology to explain the present status of fuel cell development in order to provide the United Kingdom, in particular, with the necessary background to worldwide developments in the field. U.S. and Japanese speakers predominated; other contributors came from the Netherlands, Italy, Germany and Canada. Some twenty delegates came from Japan, with an equal number from the U.S.A., and the remainder from Europe. Thus, the

attendances well-represented current world interest and commitments to the technology.

His Royal Highness the Duke of Kent, Presi- dent of the Royal Institution, opened the proceedings on the Monday evening. He briefly referred to the historic context surrounding the work on electricity of William Grove and Michael Faraday at the Royal Institution. He explained how fuel cells offered the prospect of providing a cleaner, more efficient future. He then introduced Professor J. M. Thomas, F.R.S., Director of the Royal Institution, who presented the Grove Anniversary Fuel Cell Lecture. Professor Thomas began by outlining the rich history of the Institution, where no less than fifteen Nobel Prizewinners had worked. He dwelt extensively on the remarkable career of Grove, the Swansea-born, privately educated “amateur” scientist and professional jurist. Many slide copies from the extensive archives of the Royal Institution were shown of original, often handwritten, letters and manuscripts by the great man; these included the first drawing by Grove of a four cell fuel battery. Professor Thomas then provided delegates with a series of spectacular demonstrations, in keeping with the Royal Institution tradition, illustrating the logicality of scientific thought whch had led William Grove to seek out the fuel cell as the “theoretically more’ perfect (battery) . . . (which) exhibits such a beautiful in- stance of the correlation of natural forces”. First he demonstrated the development of electric arc and filament lighting; then illustrated the explosive combidation of hydrogen and oxygen which could be initiated by a flame or a precious metal catalyst. Continuing th is theme he showed that a controlled flame could be lighted at a jet of hydrogen, again using a platinum catalyst (incredibly, the basis of one

Pkztinum Metals Rev., 1989, 33, (4), 169-177 169

early gas lighter!). Finally, the cool, controlled and continuous electrochemical combination of these gases at an electrocatalytic surface was exhibited in the first public demonstration of a small 500 W Ballard SPFC, supplied with hydrogen and oxygen, and having virtually in- stantaneously available power sufficient to drive an outboard motor.

Why Fuel Cells? The technical sessions on the Tuesday morn-

ing were opened by Professor R. Parsons of Southampton University who asked the question “Why fuel cells?”. Professor A. J. Ap- pleby of Texas A. 81 M. University began to answer this question in his Keynote Address. First, he traced the origins of Grove’s fuel cell (having only about 10 mm’ of effective area at the meniscus of his platinised platinum plate), Ostwald’s vision of a clean, electrochemically- based 20th Century, the decline of interest in the field at the turn of the Century, through to the triumph of Dr. F. T. Bacon, who was present in the audience, in the 1950s~ with the first engineered working fuel cell which used nickel electrodes. Then followed the Gemini and Apollo missions which depended on fuel cell power. Meanwhile, in the Netherlands, Ketelaar and Broers had laid the foundations for molten carbonate devices (MCFC), while other workers developed ion-conducting zir- conia for solid oxide fuel cells (SOFC). Although modern electrodes with highly dispersed noble metals supported on non- wetting PTFE substrates have revolutionised PAFC and SPFC technologies, the slow electrocatalytic reduction of oxygen was still disap- pointing. In closing, Appleby emphasised the importance that sound and innovative engineering had made, and is making, to the development of these high efficiency power generators. He suggested that the prospect of a “Hydrogen Economy” could still be achieved in time to allay the ‘‘greenhouse effect”; electric vehicles would have a major impact in reducing urban pollution.

By way of a thought-provoking scenario, M. P. Walsh, formerly of the U.S. Environmental

Protection Agency, suggested that homo sapiens might be engaged in a massive global experiment to change the entire planetary ecosphere-irreversibly ! So far the experiment appeared to be proceeding successfully; one side-effect, of course, could lead to the extinc- tion of the investigators. Expanding on the theme of global warming as well as tropospheric pollution, Walsh highlighted the presently in- adequate attention being paid to the lowering of carbon dioxide emissions produced by fossil- fuel devices, particularly vehicles. Fuel efficiency was the key and fuel cells had an important role to play. Various scenarios were indicated. However, in order to redress the balance, a combination of strategies, including a 3 per cent switch to fuel cell vehicles, starting at the turn of the century, would be required. By inference, these would most probably be low temperature fuel cells (LTFC) units and would incorporate noble metal electrocatalysts, at least initially.

Professor N. Itoh of the National Energy Development Organisation (N.E. D.O.), Tokyo, explained that although fuel cell research had been underway in Japan for a quarter of a century, it was the intervention of M.I.T.I. in 1981 under the “Moonlight Pro- ject” which elevated the scale of development towards viable, large-scale demonstrators. Presently, I MW PAFC plants are being con- structed and installed with considerable early successes. These units are aimed at the electric utility markets, whereas a parallel programme is developing 200 kW PAFC units fuelled on either reformed methanol or syngas for on-site applications. An important example included the imminent installation and development of a 200 kW PAFC type in the leisure complex at Rokko Island. Slides from several Japanese speakers showed how compact on-site PAFC units were being located in/on city centre buildings; some were already operating. Mean- while, N.E.D.O. is directing the development of MCFC stacks, currently operating at the 10 kW level but with a target of demonstrating 100 kW stacks by 1991, and I MW plants by 1995. Elsewhere, the Electro Technical


Laboratory (E.T.L.) is attempting to develop 500 W tubular SOFCs, while the National Chemical Laboratory (N.C.L.) is studying planar and monolithic configurations. Apart from these government supported efforts, Japanese industries, including the utilities, were engaged in constructing and demonstrating both their own and foreign plants, mainly PAFC and MCFC types.

The market opportunities for fuel cells were highlighted by K. A. Trimble of the G a s Research Institute, Chicago, who stressed their inherent advantages of efficiency, modularity, site flexibility and environmental acceptability. In the U.S.A. alone, 4 million sites representing 175,000 MWe peak load were in prospect with further growth potential of 2 to 4 per cent per annum, all in the commercial sector. These would comprise on-site CHP units from 25 kW to I MW size, for offices, stores and apart- ments. In the industrial sector 300,000 sites in the chemical, metal and food industries, for example, offered scope for up to 15,000 MWe peak demand, although PAFC technology would face stiff competition in some applications.

Long lead times for the construction of conventional plant, demand growth at 2.6 per cent per annum, increasingly severe environmental constraints all conspired to favour fuel cell introductions in the 1990s. However, if they can be developed in time, larger MCFC and perhaps SOFC plants could absorb much of the demand, especially for coal gas operation as the coal:oil/gas price ratio widens.

D. M. Rastler, of the Electric Power Research Institute (E.P.R.I.), California, outlined the historical context of that organisation’s $70m venture on, mainly, PAFC technology, culminating in the 4.5 MW demonstrations and the design of an 11 MW system, by United Technologies Corporation. Support was also provided for the development of the Westinghouse air-cooled PAFC units. Although recent attempts to begin commer- cialising PAFC technology had proved unsuc- cessful, E.P.R.I. continues to monitor Japanese and European demonstrations. Simultaneously

they are now directing attention towards MCFC technology as well as tubular SOFC development. Closer studies of market trends worldwide were underway.

More details of the Westinghouse achievements with air-cooled PAFC were provided by J. M. Feret, the goal being to offer plants in the 3 to 50 MW range, initially fuelled by natural gas, but eventually with fuel flexibility. Individual modules are based on the 375 kW stack, but a steam-bottoming cycle would boost an installation to I 3 MW nominal. In early tests, the 690 mV/cell target had been met or surpassed; in small stacks, an 8 mV per 1000 hour voltage decline had been approached over 16,000 hours of operation. However, the 4 mV per 1000 hour decay goal for larger stacks had been improved upon over 4000 hours of testing. In a single 100 kW stack, performance objectives were being exceeded during 2000

hours of operation. Commercialisation of the 3 MW prototype is planned for the mid-1990s. However, all aspects of stack performance, stability and cost are presently being reviewed against considerations of market expediency.

L. J. M. J. Blomen and H. N. Mugerwa of K.T.I., the Netherlands, described their company’s cautious approach to developing and marketing 25 kW and 80 kW PAFC plants. Reliability and economics, including risk shar- ing, were seen as key strategies to successful introductions. The use of standard proven components from existing hydrogen plants, would aid the development of larger plants. Designs should aim at optimum rather than maximum current density, in order to achieve the best compromise between investment costs and the ultimate cost of the electricity produced.

P. H. van Dijkum and K. Joon from Novem and E.C.N., respectively, outlined the Dutch MCFC development programme. Although Hoogovens had withdrawn from the programme, it was still hoped to build 100 kW stacks by the mid-1990s after completing trials of 10 kW, 25 cell stacks by 1991. Present efforts focused on improved performance, the introduction of new materials and the

Platinum Metaki Rev., 1989, 33, (4) 171

development of internal reforming units, the latter with British G a s .

Concluding the first day the Panel Discussion centred around the need and justification for fuel cells, with aspects of availability, timing, cost and opportunities for market introductions being considered. In a provocative contribution, Professor A. Ascoliof C.I.S.E., Italy, suggested that politicians should immediately abandon excessively expensive fusion research-which led to as much radioactive contamination (sic dirty) as in fission-and plough those resources into (sic clean) fuel cell development. Elaborating, he pointed out that fuel cells uniquely avoid the production of nitrogen oxides emissions, since electrochemical processes can be conducted below those temperatures which lead to th is highly undesirable pollutant. These comments drew a sustained and enthusiastic round of applause! Similar sentiments were recorded upon Pro- fessor Appleby suggesting that fossil fuels should, in future, be reserved for making chemical feedstock and for the conversion of water into hydrogen for efficient production of power, by way of fuel cells.

The Commercialisation of Fuel Cells

Opening the proceedings on the second day, N. Hashimoto of Osaka G a s set out their plans to bring PAFC technology to fruition from 1993, followed later by SOFC. Presently, they were ah ing to demonstrate 50 kW to 200 kW PAFC units for on-site applications using Japanese, mainly Fuji and Mitsubishi, and In- ternational Fuel Cells Corporation’s (I.F.C.) PC25, plant.

Demand for these types of plant was assessed at 1000 units per annum, each rated at 100 kW, by the mid-rggos with a cost target of $1400-2m/kW. Some details of the testing of Westinghouse 3 kW SOFC units were also provided; durability, thermal cycling and 6 per cent performance decline were of concern, but 25 kW internal reforming generators would be tested by Osaka and Tokyo Electric Power Company (TEPCO) within the next two years.

The extensive involvement of TEPCO with PAFC, MCFC and SOFC trials, dating from the late 1970s~ was described by T. Asada and Y. Usami. This work included 2423 hours of demonstration with the United Technologies Corporation’s 4.5 MW prototype, leading to the commissioning of an I.F.C. 11 MW stack scheduled to start-up in January, 1991. Sanyo 200 kW air-cooled PAFC and I.F.C. 200 kW PC25 units were presently under test. In common with statements by many other contributors, TEPCO considers that an eventual move towards MCFC or SOFC technology would depend upon the prior successful introduction of PAFC equipment. This suggests, perhaps, that it could be worthwhile for the platinum industry to redouble its short and medium term efforts in order to establish this early market opportunity in the fuel cell industry, even ifa redirection of strategy is called for in the longer term. Usami reported details of the early performance data emerging from PC25 trials-most goals are being achieved or exceeded. As well as setting out TEPCO programme objectives for the PC-23, Usami addressed the broader expectations of lifetime extension to 40,000-60,000 hours, reduced footprint of 0.1 m2/kW down from 0.3 m 2 k W and cost reduction from I million WkW to 200-300 M/W. He stressed the need for an accurate market-assessment based strategy. Again echoing other speakers, international co- operation was seen as an essential requirement.

R. Anahara indicated that Fuji Electric had concentrated on the development of PAFC technology, targeting mass production towards commercialisation in 1994. Both stationary (on- site, co-generating and dispersed power plants) and transport applications were envisaged across the kilowatt to megawatt spectrum. Not- withstanding, other work was continuing on AFC, MCFC and SOFC stacks. The company has accumulated many thousands of hours of PAFC operating experience with I MW, 200 kW and 50 kW plants. A compact 50 kW PAFC design is destined for sites in Japan, Europe, the U.S.A. and S. E. Asia. The smaller 4 kW methanol-reforming device continues to


be available. For vehicles, the 5 kW PAFC fork-lift truck power unit will spearhead attempts at market penetration, but cost reduction is the major goal. These units will be used as the basis for 50 kW bus motive power packs; a half-size 25 kW unit has already been supplied to Chrysler and is under trial. En- vironmental concerns were considered to be a strong driving force for market development, but Anahara re-emphasised the need for international collaboration.

Turning again to market opportunities, J. A. Serfass of Technology Transition Corp., Washington, D.C., wondered whether even the presently available fuel cells might not be the solution to problems as yet poorly defined-at least in the U.S.A. He considered that the characteristics offered by fuel cells would be desirable in the longer term, however. Simplification of designs would convince early users that cost reductions would be achievable. A clearer identification of present market trends seems essential in the near-term. The American Public Power Association (A.P.P.A.) had taken the initiative by calling for small, municipal units. While public power accounted for only 15 per cent of the U.S. market, this still represented 1-2 GW per annum for 15 years! Markets exist today in Europe, Asia and N. America for early fuel cells in constrained areas and these cells would find willing buyers if the $110o/kW barrier could be met.

Closing the morning session, during the Panel Discussion, N. Hashimoto, in response to a question, indicated that the next major strategic programme evaluation and decision to continue (or otherwise) with fuel cell demonstrations would occur in about 2 to 3 years; R. Anahara remained confident for the future. Discussion ensued on early market costs and niche markets; J. A. Serfass warned that while in the U.S., at least, users could not ex- pect to include cost-reducing credits on the basis of environmental factors, there were still some A.P.P.A. clients who could bear present fuel cell prices with more in prospect at lower mature-market costs. R. Anahara explained that cost depended on many factors, market

size being the most important. Professor Ap- pleby suggested that best investment policy would be obtained by having a broad portfolio of power generating options of which one might be fuel cells. Trimble advised that, in the U.S.A., 1994 emission-control standards could not be met unless new technology were introduced. Professor Ascoli referred to niche markets, such as historic city preservation, where costs were not the primary consideration; these might well take advantage of fuel cells at an early stage. Attention was also focused on the intended introduction of electric vehicles in Los Angeles, for example, the through-life costs of their batteries, their rechargeability and the scope for fuel cell only or fuel cell-battery hybrid vehicles according to usage and location.

European Fuel Cell Interests The Commission of the European Com-

munities (C.E.C.) was concerned to see the urgent introduction of more efficient, less polluting power sources, according to P. Zegers. Fuel cells with battery storage seemed attractive. Power plants, co-generation systems and electric vehicles could all help to lower the net carbon dioxide per calorie rate. In Europe, PAFC, MCFC and SOFC were being actively pursued, both ~ t i ~ ~ l l y and with C.E.C. collaboration. In MCFC technology, the C.E.C. particularly wished to promote a I kW internal reforming demonstration by 1992. Elsewhere, it was developing two I kW SOFC stacks to be operational within the same timeframe. For vehicle development, long term research on direct methanol fuel cells (DMFC) had been undertaken under C.E.C. programmes, while the Italians were investigating PAFC and SPFC plants as well as methanol reforming.

R. Vellone of E.N.E.A. explained how, since 1983, that organisation had co-ordinated all M- tional fuel cell interests under the “Volta Pro- ject”. Italy wished to reduce dependency on imported oil and to improve pollution levels in their dense urban communities. Large savings could be achieved by any fuel cell introduction scenario, but these savings could be trebled if


cost-reduction targets, legislative support and an indigenous producer industry could be arranged. However, in view of the technical maturity of PAFC, no further Italian effort was envisaged, rather demonstration programmes were planned using U.S. or Japanese stacks with Italian peripherals. R. Dufour of Ansaldo, in an unscheduled supplementary comment, indicated that Milan would install a I MW PAFC capacity for 1991 using I.F.C. 670 kW units with Ansaldo engineering and A.E.M. monitoring. Bologna will install a 25 kW PAFC on-site plant for 1990 with Fuji stacks and K.T.I. engineering, with a similar configuration to follow at Casaccia, Rome, both with C.E.C. support. Options for an I.F.C. 200 kW PAFC purchase are being examined. Smaller, portable I kW and 5 kW stacks are being developed for E.N.E.A. and the Italian Ministry of Defence using both foreign and Italian stack technology. A second aspect of the “Volta Project” is to develop MCFC technology; a foreign col- laborator is being sought. At present Ansaldo has built and tested small cells; C. N. R. -T. A.E., Messina, has acquired 30,000 hours of experience testing I.G.T. single cells and has developed an internal reforming catalyst. C.I.S.E. is developing novel cathodes. Supporting activities are underway elsewhere. Further, an E.N.E.A./De Nora initiative is planning a 10 kW SPFC stack for 1990, while several organisations are commencing SOFC studies with C.E.C. support. Overall, about $28.5m is being earmarked for Italian fuel cell programmes, some 63 per cent from E.N.E.A.

Future Prospects B. Riley of Combustion Engineering, Con-

necticut, U.S.A., briefly outlined the three main SOFC configurations, their component parts, materials of fabrication, and performance targets. Against these considerations, it was possible to match types and sizes with the likely “commercial window” in’the 1990s. Both present and future fabrication procedures were described. All these factors are interactive, but target costs should meet $I 5mkW installed, $350-4OOkw stack and $50-70/kw materials.

Quality control should dominate throughout and critical areas for attention were highlighted, especially with regard to scale-up. Allied Signal apparently have developed some very advanced designs for internally- manifolded flat plate devices.

Considerable excitement was generated by K. Strasser of Siemens AG who described their recent successes with the 6 kW AFC modules. Apart from space application, alkaline cells have tended to receive less attention recently. Using silver cathodes and nickel anodes and a recirculating potassium hydroxide electrolyte at 8o°C, cells can provide o.8V at 4oomA/cm2 at approximately 2 bar; thus a 60 cell stack provides 6 kW at 46-48V and with an efficiency of 61-63 per cent (71-72 per cent at 20 per cent load). Detailed performance data was discussed, including load following and start-up. Some 20,000 hours experience has been gained with an 8 x 6 kW assembly giving approximately 50 kW output; performance decline had been negligible. Most recently, a 100 kW system had been tested successfully in a submarine.

At this point, the format of the symposium was modified to accommodate six short contributions. However, the first two of these from W. Kumm of Arctic Energies and V. W. Adams of the U.K. Ministry of Defence both echoed the theme of marine applications. Substantial fuel savings were apparently in prospect for shipping. PAFC might have a role, but MCFC and SPFC are potentially more competitive than diesel-electric. SOFC might be viable, if successfully developed. For best advantage a diesel fuel reformer would be needed to permit hybrid power operations from the single currently available fuel. For military and submarine applications, LTFCs offer low noise and low infrared signature profdes. Next, G. Thomas of D.T.E., outlined the earlier fuel cell involvements of the Royal Navy, and offered opportunities for future collaborative ventures. The reticence of the Royal Navy in respect of fuel cells was puzzling in the context of the papers from Strasser, Kumm, Adams and Thomas. Certainly, if LTFC were adopted for military vehicles, this would represent a


considerable requirement for noble metal electrocatalysts.

Two further short contributions by M. Washay of NASA-Lewis and H. Van den Broeck of Elenco considered AFCs for space and ground transport, respectively. The regenerative space module, essential for extended lunar and Martian missions, was highlighted later. The 70 kW hydrogen-oxygen cell of Elenco had now completed the design phase with EUREKA support, and construction would begin soon. A consortium had been assembled to oversee the introduction of a fuel cell city bus for Amsterdam. Cryogenic hydrogen storage was being adopted.

Further excitement was generated by the final contribution from C. Dyer of Bellcore, who described a recently patented novel “fuel cell”. The device consisted of thin f h overlays of metal/membrane/metal laid down upon an insulating substrate. The membrane material did not seem to be critical, both oxidant and reactant gases were present in the same gas stream with separation occurring within the membrane; invariably, the oxidant was parti- tioned and appeared to interact with the inner electrode, contrary to expectation. The assembly could be produced in a continuous strip in a back-to-back configuration and rolled between spacers to form gas channels. In this way larger currents could be generated; a I volt per cell output was typical. Although different polarities and voltages could be obtained by using different electrodes, best performances were evident if both were platinum, suggesting, perhaps, that the adoption of modem alloys and commercial dispersions of noble metals might be advantageous. Opening the f a session, F. Baron of the

European Space Agency described the development of regenerative AFCs for the Hermes and Columbus projects. Two 4.6 kW units were required for the twelve-day Hermes mission, and Dornier were engaged in development with Aerospatiale. Suppliers under consideration included Elenco, Siemens and Varta. Much detailed performance goal data was illustrated; both static and recirculating electrolyte con-

figurations had been considered, but the former was presently favoured. Other designs incorporating proton-conducting membrane electrolyser-AFC hybrids had proved less effective in trials. A bread-board approach to development was being adopted, with feasibility being demanded by the end of 1990 in time for first flights in early 1997.

The inherent advantages of all-solid state, low temperature SPFCs, were outlined by K. Prater of W a r d Technologies, Vancouver, Canada, who traced their development from early General Electric devices used in Gemini missions. The advent of Nafion had provided impetus to SPFC development and the new Dow membrane appeared to offer further improvement. W a r d efforts had begun in 1984 in response to Canadian Defence requirements. A 54-cell stack capable of operating on air or oxygen had been developed, and was very tolerant of carbon dioxide; pretreatment of the gas stream to selectively oxidise carbon monoxide had proved possible. Cost reduction was being achieved by the use of low cost graphite plates, and by substantially reducing the platinum loading from 8 mg/cmz perhaps to 0.7 mg/cm* . A 2 kW device had recently been installed in a manned submarine with outstanding performance, including a dramatic extension of duration by more than one order of magnitude; a 10 kW hydrogen-air unit would be hybridised into a Dow chlor-alkali plant. Major motor manufacturers as well as defence contractors were becoming interested in SPFC technology and new market opportunities could arise. Concern was expressed that membrane cost and availability could be limiting factors, but recent assurances had been received from Dow. Further noble metals loadings reductions were in prospect, perhaps to 0.1 mg/cmz. In the f d paper, R. Lemons of the Los

Alamos National Laboratories highlighted the problems of transport dependence on petroleum supply (62 per cent of U.S. consumption) and the concommittant pollution that arose therefrom. Although alternative fuels, including renewable fuels, were being scrutinised for this use, the combination

Platinum Metah Rev., 1989, 33, (4) 175

of methanol (reformed) in a fuel cell vehicle appeared particularly attractive, giving a doubling of range over an internal combustion engine, with a consequent lowering of carbon dioxide emissions. Due to the stringent specifications to be met in this market sector, fuel cell types needed to be carefully matched to the application. Thus, for road vehicles SPFC and AFC types of LTFC offered the best start-up and wide power band performances. A SOFC monolith might prove viable. At Los Alamos, major progress had been achieved with SPFC technology; platinum loading had been reduced to <o.5mg/cm2 and power densities >o.gW/cm2 had been achieved with experimental membranes at current densities of 2A/cm2. Recent work had shown that a performance recovery from carbon monoxide poisoning could be obtained by air-injection at the anode. The U.S. Departments of Energy and of Transport were initiating co-operative development programmes with industry to explore fuel cell-battery hybrid systems for urban buses. In- itially PAFC units would be used. Much research and development remained to be undertaken if maximum benefit were to be obtained from fuel cell introductions in the transport field.

Summary and Conclusions A final Panel Discussion reviewed the way

forward for fuel cells, followed by a summary and closing remarks by Professor Appleby.

Global warming and tropospheric pollution were identificd as issues of current concern. Significantly, the Japanese had gained considerable operating experience with fuel cells already and apparently had a clear commitment for their future manufacture, demonstration and commercialisation. Likewise, U. S. Agen- cies had a long track record of commitment to fuel cells. The Dutch, who had initially resear- ched the MCFC two decades ago, had made outstanding progress with these systems in the last three and a half years by purchasing United States know-how to incorporate into their own programmes. Now, the Italian fuel cell effort was intensifying. Materials research and

development in Europe was strong. Ultimately, Appleby envisaged a diverse

range of fuel cell applications due to their low environmental impact. Elenco had identified liquid hydrogen as the best method of fuel storage for the vehicle and this would power their alkaline cell stack in the Amsterdam bus project. The promise of I MW/m3 SPFCs, representing 700 Wkg, could lead to viable trac- tion power plants (volume to power to weight 50

litres, 60 kW and 90 kg, respectively). Both engineering and materials development

were central to the success of fuel cells. However, political factors and legislation were equally determining. Their inherent efficiency implied a reduced environmental carbon dioxide impact; coupled with their very low “classical” pollutant emissions, notably nitrogen oxides, they would commend themselves strongly to the general public. Presently, it was necessary to address cost and reliability matters, while identifying early market niches. Increased power densities, reduced weight of repeat-parts and improved gas distribution networks, constituted areas for detailed development. The high power of AFCs appeared attractive, as well as their capability for instantaneous start-up, provided gas-scrubbing could be economically addressed. SPFCs needed to achieve substantial cost- reduction, particularly regarding presently available membranes. Furthermore, SPFCs might lose their performance edge if pressurisa- tion was needed. This would account for as much as I 50 mV-equivalent from the available output of approximately 0.7 V at 300 mA/cm2.

In essence, PAFC required manufacturing cost reduction, improved engineering and improved performance; MCFC needed materials development, in particular, cathode integrity improvement. For SOFC, lightweight, low cost targets had to be met and innovative manufacture was called for.

Professor Appleby saw hydrogen as the natural fuel of the future and fuel cells represented the only logical conversion devices. However, methanol should not be overlooked.

Overall, the symposium was well planned and co-ordinated and it attracted the correct


balance of speakers and delegates. Clear market opportunities were evident across many industrial and governmental interests, including the platinum industry.

In summary, the symposium had heard about the present developments and commercial availability of fuel cells. Notably, the demonstrations of 200 kW on-site PAFC units was to proceed. Major advances were being made in MCFC technology and these devices still offer perhaps one of the best options for fuel cell power production. SPFC technology had

Thermomagneto-Optical

shown dramatic progress through lower noble metal electrocatalyst loadings, and with increased current densities being reported. SOFC still required much research and development but could represent a serious option later.

With so much demonstrable progress evident, albeit predominantly in the U.S.A. and Japan at present, the promise for fuel cells in a cleaner, more efficient future is still as bright as Grove foresaw so long ago.

The full proceedings will be published in the Journal of Power Sources.

Recording Materials COBALTlPLATINUM LAYERED STRUCTURES OFFER ADVANTAGES

Rewritable optical storage technology offers an attractive alternative to current magnetic recording, particularly with a capability to store 108 bits of information for each square cen- timetre of media material, together with remote optical reading, writing and erasing procedures. To date, the most promising candidates for magneto-optical recording are based on rare earth-transition metal (RE-TM) alloys deposited as thin amorphous layers on a variety of substrates. Such materials include variants of GdTbFe and TbFeCo.

Two recent publications by scientists at the Philips Research Laboratories, Eindhoven, and at the Central Research and Development Department of E.I. du Pont de Nemours, Wilmington, have highlighted both the deficiencies of current magneto-optic media based on RE-TM materials, and their advantages (I, 2) . However, investigations by these researchers into the magnetic and magneto-optic characteristics of cobalt/platinum layered structures are clearly pointing the way to new magneto-optic media with enhanced properties, many of which overcome the deficiencies of current RE-TM based materials. For example, the cobalt/platinum layered structure media have excellent corrosion and oxidation resistance which eliminates the need for protective coatings. Also perpendicular magnetic anisotropy, a pre-requisite for advanced magneto-optical systems, has been achieved in these layered structures without the need for high temperature annealing, as in the case of proposed oxide candidates.

The authors in their respective papers present and discuss recent research findings on the

magneto-optical Kerr effect of various cobalt/platinum layered structures, with differ- ing thicknesses of cobalt and platinum. Preferential magnetisation perpendicular to the film planes has been shown for media having cobalt thicknesses <I.Z nm, with 100 per cent perpendicular remanence at cobalt thicknesses <0.45 nm. A multi-layer system having 25 layered structures of 0.41 nm cobalt and 1.9 nm platinum was used to demonstrate thermomagneto-optic writing. This media system proved to have good perpendicular magnetic anisotropy, 100 per cent remanence and a coercive field of 76 kA/m, at room temperature.

Environmental stability tests were carried out on unprotected cobalt/platinum layered structures stored at ambient for several months. No sign of oxidation or corrosion, and no corrup- tion of the magnetic and magneto-optical data was apparent on these media, which are considered to be promising candidates for magneto-optical recording.

Attention is drawn to another informative paper on the magneto-optical properties in ultra-thin cobalt/platinum and cobalt/palladium multilayer films, from the Sony Corporation Research Center, Yokohama, Japan, which is abstracted on page 222 of this Journal.

I.R.M.

References W. B. Zeper, F. J. A. M. Greidanus, P. F. Carcia and C. R. Fincher, J. Appl. Phys., 1989,65, (Iz), 4971 F. J . A. M. Greidanus, W. B. Zeper, F. J. A. den Broeder, W. F. Godlieb and P. F. Carcia, Appl. Phys. Lett., 1989, 54, (24), 2481


References I W. B. Zeper, F. J. A. M. Greidanus, P. F.

Carcia and C. R. Fincher, J. Appl. Phys., 1989,65, (1219 4971

2 F. J . A. M. Greidanus, W. B. Zeper, F. J. A. den Broeder, W. F. Godlieb and P. F. Carcia, Appl. Phys. Lett., 1989, 54, (24), 2481

Towards a Cleaner Environment CATALYTIC INCINERATION IN THE PRINTING INDUSTRY

By T. J. Lawton

Catalytic combustion is a safe way of destroying volatile organic compounds produced during a variety of manufacturing and processing operations, while the ability to recover heat is an additional benefit.

Johnson Matthey, Catalytic Systems Division, Royston

A wide range of industrial processes that provide useful products simultaneously generate waste gases which may cause atmospheric pollution. In particular, emissions of volatile organic compounds are often responsible for odours that cause local nuisance. More widespread environmental damage may result if these compounds react with nitrogen oxides in the presence of sunlight to form tropospheric ozone, causing photochemical smog and resulting in damage to plant and animal life.

The most effective way of ensuring essentially complete destruction of volatile organic compounds present in gaseous effluents is incineration. This can be performed by direct flame heating in a combustion chamber, at temperatures which are usually in excess of 7ooOC. However, if a suitable catalyst is incorporated into the incineration system the oxidation reaction, that is the combustion of the organic compounds to carbon dioxide and water vapour, takes place at significantly lower temperatures and at a much faster rate, resulting in both reduced fuel consumption and lower capital investment costs.

Catalysts for air pollution control applications should be active at relatively low temperatures and must be chemically and physically stable in oxidising atmospheres. Largely as a result of the requirements imposed by the adoption of catalytic afterburners for the control of automobile exhaust emissions, a range of advanced catalysts are now available to meet these demanding criteria.

The development of ceramic honeycomb support materials, and improved methods of impregnating them with catalytically active

platinum metals, presents a major opportunity for their use in catalytic incineration systems for industrial air pollution control. The thin walled honeycomb materials have a very high surface to volume ratio, and their resistance to gas flow is an order of magnitude lower than that exhibited by a pelleted or granular catalyst bed of the same geometric shape and size. The inherent stability of the platinum metals employed and their high activity as catalysts in oxidation reactions of the type experienced in air pollution control applications impart a long effective life to the catalyst, and minimise operating fuel costs.

The Honeycat@ Air Pollution Control System

The basic components of a typical Honeycat@ air pollution control system, designed and engineered by Johnson Matthey, are shown opposite. The contaminated process exhaust air is pre-heated to the temperature required to sustain the oxidation reaction in the catalyst bed. The combustible organic compounds in the air stream react with oxygen on the surface of the catalyst to produce what is essentially carbon dioxide and water vapour. The clean hot air then passes back through the heat exchanger where 50 to 70 per cent of the heat content is transferred to the incoming contaminated air stream. The cool air may then be either exhausted directly to the atmosphere or additional heat can be recovered for use elsewhere.

All catalytic oxidation reactions require a minimum temperature to be reached before any significant degree of oxidation will occur. The

Platinum Metals Rev., 1989, 33, (4), 178-180 178

Table I

Comparative Operating Temperatures for the Oxidation of

Volatile Organic Compounds

I

' The Honeycat@ pollution ~ control system is based upon SECONDARY

the catalytic properties of the EXCMANGER ~ platinum metals oxidation

catalyst formulation, which is dispersed over the surface of a ceramic honeycomb sup- I port. The latter causes o n ~ y low resistance to gas flow, and the unit withstands both

temperature cycling. The GASES ability to recover heat energy from the system is an addi-

high temperatures and EXHAUS PREHEATER

F- PROCE

tional benefit PRIMARY HEAT EXCHANGER -

Contaminant I Formaldehyde

Carbon monoxide

Styrene

Paint solvents

Phenol/

Phenol/creosol

Ethyl acetate

formaldehyde

Honeycat@ incineration,

OC

100- 1 50 250 350 350

400

400

3 50 -400

Thermal incineration

OC

825 800 880 8 50

800 800 7 50

temperature required for essentially complete reaction is dependent upon the type of catalyst and the time it is in contact with the contaminated airstream. Typical operating temperatures for the destruction of various volatile organic compounds by direct flame heating, and over an appropriate platinum metals catalyst, are given in Table I. An analysis of the constituents of a contaminated

process airstream can therefore be used to define the catalyst operating temperature necessary to achieve the required degree of fume removal.

The design of a catalytic incineration plant is very dependent on the temperature of the process exhaust stream. When this temperature is above that required to sustain the catalytic oxidation reaction, no additional heat is required, fuel costs are zero, and the capital cost of the in- cinerator unit is relatively low. More usually the process exhaust gas temperature is lower than the catalytic oxidation temperature, so some preheating is necessary. In many cases, however, preheat is only required for start-up, since if the concentration of the contaminants in the process stream is relatively high, the amount of heat generated by the oxidation reaction is then sufficient to heat the incoming gas stream to the required oxidation temperature.

Types of Pollution Controllable by Catalytic Incineration

Emissions that can be controlled by catalytic means include those from processes involving a natural product such as food, drying or curing solvent-containing products, and chemical processes which produce gaseous organic emissions

PURIFIED EXHAUST GASES TO ATMOSPHERE


~~ ~

Table It

Industries Using Honeycat@ Systems

Paper printing and coating

Metal decorating and printing

Food processing

Food frying

Animal rendering

Coil coating

Wood and board printing

Carpet manufacture

Tobacco drying

Organic chemical manufacture

or nitrogen oxides in oxygen deficient atmospheres. Industries currently using Honeycat@ systems are listed in Table 11.

Honeycat@ Technology Applied to the Printing Industry

Printing is one specific industry which has benefited considerably from the use of catalytic incineration systems. The web-offset printing process uses solvent-based inks in large quantities. Once the inks have been applied to the paper all of the solvent is driven off in the print drier, with the result that heavily solvent-laden air is exhausted from the process. Increasingly planning or environmental protection authorities are placing restrictions upon the emissions that can be discharged from an industrial process. These regulations vary in different locations, but typical emission levels require catalyst efficiencies ranging from 95 per cent to greater than 99 per cent removal of the volatile organic compounds for many thousands of plant operating hours.

One of Europe’s largest printing companies, Jarrold Printing of Norwich, England, specialising in the printing and binding of high quality magazines, catalogues and books has now installed its third Honeycat@ system to treat the exhaust gases from print drying units. Jarrold installed its first Honeycat@ system in

1985 following a successful on-site demonstration using a mobile Pilot Plant Unit (I). The trial was witnessed by members of the Norwich Environmental Department who expressed their satisfaction with the results.

The Honeycat@ system was designed with a primary heat exchanger to preheat the incoming process gases, thus reducing the energy in- put requirement. Depending on the process conditions and solvent loadings the requirement for additional energy may be eliminated. Indeed, the temperature rise of around 8ooC across the catalyst justified the installation of a secondary heat exchanger to provide hot water for factory heating. With the recent commissioning of the third Honeycat@ system at least 50 per cent of the thermal energy needed to heat the factory in the coldest part of winter will be available, thus significantly reducing costs while controlling exhaust pollution.

There are now seventeen Honeycat@ systems, designed and engineered by Johnson Matthey to comply with the local pollution regulations, operating on printing processes. These form part of over two hundred Honeycat@ installations controlling the emission of volatile organic compounds from a vast range of industries throughout Europe.

Acknowledgement

Matthey PLC. Honeycat@ is a Registered Trade Name of Johnson

Reference 1 Anon, Platinum Metals Rev., 1987, 31, (3), 122

Monitoring Combustible Gases A recent report from Case Western Reserve

University, Cleveland, Ohio, describes an experimental study of miniature thick-film calorimetric sensors which show good sensing characteristics for carbon monoxide, hydrogen and hydrocarbon gases. (A. Chen, R. Luo, T.-C. Tan and C.-C. Liu, Sens. Actuators, 1989, 19, (31, 237-248).

A pair of identical platinum heaterhesistance thermometer films are employed; one is coated with a platinum black or palladium oxidation catalyst while the other serves as a compen- sating element. Any resistance change due to heat released on catalysis can be related to the concentration of the combustible gas.

Plarinum Merals Rev., 1989, 33, (4) 180

Ruthenium and Osmium 0x0 Complexes as Organic Oxidants By W. P. Griffith Department of Chemistry, Imperial College of Science, Technology and Medicine, London

Recent advances in the application of ruthenium tetroxide, lower-valent 0x0 ruthenates and osmium tetroxide are summarked here, with particular reference to uses or potential uses of these materials in the fine chemicals industry.

Ruthenium and osmium are unequalled in the entire Periodic Table in that they can sustain, in a handful of complexes, the VIII oxidation state; no other elements exhibit octavalency. In most of these complexes, and also in many other complexes of these two elements in the VII, VI, V and IV oxidation states, the strongly u- and *-donating 0x0 ligand 0’ - has a dominant role. A number of 0x0 complexes involving these higher oxidation states have been used in homogeneous organic oxidations, and this paper will concentrate, for the most part, on recent advances in these areas.

Being a second-row transition element, ruthenium will hold its outer d electrons more tightly than will osmium, so that, for a given complex in a given oxidation state, the ruthenium complex will tend to be more oxidising than its osmium counterpart. Thus, for example, ruthenium tetroxide is a more powerful oxidant than osmium tetroxide, and the perruthenate ion [RuO,I- is more oxidising than tOsO,l-. The range of ruthenium-based oxidants for organic chemistry is consequently greater than for osmium, though osmium tetroxide is unrivalled in its degree of efficiency and selectivity in some types of reaction.

Ruthenium Ruthenium Tetroxide This is the best known and most commonly

used ruthenium oxidant. Ruthenium, the last of the six platinum metals to be isolated, was discovered by Karl Karlovich Klaus

(1796-1864) in 1844 (I); but he did not isolate the highly oxidising and consequently rather unstable ruthenium tetroxide until 1860 (2).

This was long recognised to be a powerful oxidant, but it was not until 1953 that a systematic survey was made of its reactions with organic substrates (3). There are now two comprehensive reviews on the use of ruthenium tetroxide as an organic oxidant (4, 5).

Ruthenium tetroxide is a pale yellow material with a high vapour pressure at room temperatures; it melts at 25OC and its density is 3.28 g/cm3, Its solubility in water is fairly low, only 1.7 per cent at o°C and 2.1 per cent at 5ooC, but it is very soluble in those organic solvents with which it does not react, such as carbon tetrachloride and cyclohexane. It is tetrahedral in the gas, liquid, solid and solution phases.

Because of its high vapour pressure, vigour of oxidation and toxicity, ruthenium tetroxide is hardly ever used on its own. However it is very easily generated in an aqueous solution from RuCI,.nH,O, or RuO,.nH,O (a better starting material), with excess aqueous sodium periodate (4), sodium hypochlorite (bleach) (4) or sodium bromate (6). In the presence of these co-oxidants it functions as a catalytic oxidant, ruthenium tetroxide being regenerated after reaction with the organic substrate by the co- oxidant, so that the actual quantity of ruthenium needed is very small. Oxidations are effected either in aqueous solution or in a biphasic system, the non-aqueous phase usually being carbon tetrachloride. Excess ruthenium


tetroxide can be removed with 2-propanol, which is oxidised by it to acetone (4, 7, 8).

Although ruthenium tetroxide is generally considered to be a vigorous and rather non- selective oxidant it is its very vigour, its ability to function at room temperature and the relative ease with which it can be prepared in a catalytic form which make it attractive for some oxidations. It will oxidise alkenes, alkynes, alcohols, aromatic rings and ethers, cleaving double bonds and some aromatic rings. It is, perhaps, most commonly used by organic chemists for the oxidations of secondary hydroxyl groups in carbohydrates to ketones, such as, for example, the oxidative formation of a dose derivative, which is shown below in Scheme I (4, 9), and for the oxidation of steroidal alcohols to ketones, either for the oxidation of hydroxyl groups to keto functions as in the oxidation of cholestan-3P,6P-diol- 3-acetate to cholestan-3/3-ol-6-one-3-acetate, Scheme 2, or for the cleavage of aromatic rings in such systems (4,8).

It has additional useful applications. It will cleave some aromatic rings; for example, it ox- idises naphthalene to phthalic acid and cyclohexanebenzene to cyclohexane-carboxylic acid ( 4 ~ ) .

The use of ruthenium tetroxide in pollution control has been covered in this Journal

previously (10) and so will be mentioned here only briefly. The possibility of using catalytic ruthenium tetroxide-hypochlorite catalytic mixtures to destroy dioxins has been demonstrated ( I I), as has its capacity to destroy oxidatively other industrial pollutants such as organosulphur reagents and polychlorinated biphenyls (PCBs) (12, 13).

Oxoruthenium Complexes as Selective Oxidants

Ruthenium (MI). Despite the uses to which ruthenium tetroxide has been put it cannot be described as a delicate reagent; its virtues lie in its powerful oxidising ability. By using oxoruthenium complexes in which the metal is in a lower oxidation state, however, gentler oxidations can be accomplished, and much research has been done in this area in recent years. There is great need in the fine organic chemicals industry, for example pharmaceutical manufacture, for oxidants which are regioselective and/or stereoselective, and thus able to bring about the oxidation of a specific group without affecting other sensitive groups.

The perruthenate ion IRuO, 1 - has long been known, and is a rare example of hep- tavalent ruthenium. In aqueous base it does indeed function as a milder oxidant than ruthenium tetroxide, converting primary

H2C-0 RU 06

Scheme 1 HO

OH Scheme 2 0


alcohols to carboxylic acids and secondary alcohols to ketones (14, 15). It cleaves double bonds in such alcohols, in addition to oxidising them, and is not catalytic in its action. However, the addition of tetra-n- butylamrnonium hydroxide ((“C, H,),N)OH to the aqueous [RuO,l- ion gives {(“C,H,),N}[RuO,l, which is readily soluble in a wide range of solvents, and will oxidise primary alcohols to aldehydes, and secondary alcohols to ketones without attacking double or allylic bonds (16). This salt, which we have called “TBAF’”, and its tetra-n-propylammonium analogue ((“C , H , ) , N)[RuO, 1 ( “TPAP”) , can more easily be made by passing a current of air through a mixture of RuO, .nH,O in aqueous sodium periodate and carrying the ruthenium tetroxide so formed into an aqueous basic solution of tetra-n-propyl- or tetra-n- butylammonium hydroxide ( I 7, I 8). The deep green TPAP or TBAP precipitates, TPAP in higher yield than TBAP. These can readily be dissolved in dichloromethane or acetonitrile and will function catalytically if N- methylmorpholine-N-oxide (NMO) is used in excess as a co-oxidant (17).

A wide range of selective oxidations has been

performed by TPAP in particular; when used in acetonitrile with powdered molecular sieves, to remove water formed during reaction. It will oxidise alcohols without affecting such otherwise sensitive linkages as epoxides, lactones, indoles, silyl ethers, acetals and tetrahydropyranyl functions. A recent example of its use in the synthesis of a natural product is one stage (Scheme 3) in the preparation of the anti-parasitic reagent htilbemycin P I (19).

Ruthenium(VI). The ruthenate ion trans4RuO , (OH) , I - has an unusual trigonal bipyramidal structure, below ( 2 0 ) ~ and can be

OH 2‘

OH generated very simply from RuCl , .nH, 0 or RuO, .nH,O in base with excess persulphate. The ruthenate ion then functions as a two- electron oxidant, oxidising primary alcohols to carboxylic acids and secondary alcohols to ketones, itself being reduced to ruthenium dioxide (21). The excess persulphate then functions as a co-oxidant re-oxidising the ruthenium dioxide back to trans-[RuO,(OH),l - so that the system is catalytic just like RuO,/IO, -. As might be expected, it is a much gentler oxidant than ruthenium tetroxide, although less so than


TPAP. Nevertheless allylic alcohols are partially cleaved by it (15). It has recently been observed that in some systems this reagent will oxidise nitro to keto groups (22), a reaction which should be investigated further. The species trans-[Ru0,(H10,),16- is also very like ruthenate in its action towards alcohols, but unusual in that it is an overall six electron oxidant with both the ruthenium(VI) centre and the two iodine(VI1) ligands each function- ing as two electron oxidants. This complex is made from RuO, .nH, 0 and periodate in base, the latter preventing further oxidation to ruthenium tetroxide, and is catalytic with periodate (10, -) as co-oxidant (23).

The dimeric species Ru,O,py,, made from ruthenium tetroxide and pyridine (py), is soluble in dichloromethane and acetonitrile and is an overall eight electron oxidant (four electrons per metal atom):

0 0 It behaves rather like TPAP, oxidising primary alcohols to aldehydes and secondary alcohols to ketones. It is catalytic in the presence of NMO but is also catalysed by oxygen at room temperatures, albeit with modest turnovers (24). A number of other ruthenium(VI) oxidants have been studied; for example, trans-[RuO,(porph)l, where porph is tetramesityl-porphyrin, will effect aerobically catalysed epoxidations of alkenes (25), while a variety of macrocyclic complexes of the form trans-[RuO,(R-TMC)] + will oxidise alcohols and epoxidise alkenes (R-TMC = macrocyclic tetra-aza nitrogen donor ligands) (26).

Osmium Osmium Tetroxide

This was the first form in which osmium was isolated in 1803 by the English chemist Smithson Tennant (1761-1815) (27).

Like ruthenium tetroxide, osmium tetroxide is a pale yellow solid with a substantial vapour pressure at room temperature. It melts at 40.6OC, boils at 121.2OC and has a density of 4.906 g/cm3. Its solubility in water is 7.2 per cent at 25OC, but it is much more soluble in inert organic solvents. Because it is a much milder oxidant than ruthenium tetroxide it is in some ways easier to use, although, like the latter, it is often used catalytically in conjuction with co-oxidants such as chlorate, tert- butylhydroperoxide, NMO, hypochlorite, hydrogen peroxide, chloramine-T and N-chloro-N-argentocarbamates, either in a single or a biphasic system.

The author wrote a short article on osmium tetroxide and its applications in Platinum Metals Review some years ago, (28), and there are two recent and comprehensive reviews on osmium tetroxide as an oxidant (29,30). It is of course milder than ruthenium tetroxide, but will cause the oxidation of a number of organic substrates. Its pre-eminent use is, however, for the stereoselective cis-hydroxylation of alkenes to vicinal diols, that is, glycols. As an oxidant it has unparalleled efficiency and smoothness of reaction for this process. An exciting recent development, of great interest and application to the fine organic chemicals and pharmaceuticals industries, is the production of optically active glycols by the asymmetric catalytic osmylation of alkenes. The procedure was first employed by Sharpless who used the acetates of quinidine and hydroquinidine as chiral amines weakly bound to the osmium tetroxide. Curiously, pyridine and other tertiary amines, which are often used to accelerate the osmium tetroxide-alkene reaction, have an inhibitory effect on asymmetric osmylation. The use of NMO as a co-oxidant renders the reaction catalytic and extremely efficient; very little osmium tetroxide is required (31).

Footnote Because of their high volatilities at room

temperature and the toxicity of their vapours, both ruthenium tetroxide and osmium tetroxide should be handled with great care in well-ventilated fume cup- boards. Solutions containing these materials in catalytic quantities are, however, far less hazardous.


References I K. Klaus, Uch. Zap. Kazamkaya Univ. , 1844, 17 W. P. Griffith, S. V. Ley, G. P. Whitcombe and

A. D. White, 3. Chem. Soc., Chem. Commun.,

18 A. c. Dengel, A. M, El-HendaV and w. p. Grif-

I9 N. J. Anthony, A. Armstrong, s. v. Leynd A Organic Chemistry”, Vol. B, ed. W. S. Madin, Tetrahedron Lett., 1989, 30, 3209 Trahanowsky, Academic Press, New York 1973, 20 M. 0. Elout, W. G. Haijie and M. J. A. P. I77

5 J. L. Courtney in “Organic Syntheses by Oxida- 21 M. Schroder and W. P. Griffith, 3. Chem. Soc., tion with Metal Compounds”, ed. W. J. Meiis and c. R. H. I. de Jonge, 22 E. J. Grey and A. G. Myers, 3. Am. Chem. Soc.,

15 2 K. Klaus, 3. Prakr. Chem., 1860, 79, 43 19877 1625 3 C. Djerassi and R. Engle, 3. Am. Chem. SOC.,

4 D. G. Lee and M. van der Engh in “Oxidation in fith, Trans. Met. Chem., 1989, 14, 230 1953, 752 3838

Maaskant, Inorg. Chem., 1988, 27, 610

Chem. Commun., 1979, 58 New york,

1986, P. 445 1985, 107, 5574 6 s. Giddin@ and A. Mills, J. Org. Chem., 1988, 3. %. Chem., Ig88, 23 A. M. El-Hendawy, W. p. Griffih, C. A. 53. 1103

19743 39, 2264

O’Mahoney and D. J. Williams, 3. Chem. Soc., 7 J. C. Sheehan and R. W. Tulis, 3. erg. Chem., Dalton Tram., 1988, 1983

24 A. M. El-Hendawy, W. P. Griffith, M. N. 8 H. Nakata, Tetrahedron, 1963, 19, 1959 Moussa and F. I. Taha, 3. Chem. SOC., Dalton 9 R. F. Butterworth and S . Hannessian, Synthesis, Trans. 1989, 901; A. C. Dengel, A. M. El- 1971, 70 Hendawy and W. P. Griffith, ibid., submitted for

10 E. S. Gore, Platinum Metals Rev. , 1983, 27, (3), publication I I I ; see also ibid., 1988, 32, (4), 186 25 J. T. Groves and K.-H. Ahn, Inorg. Chem., 1987,

I I D. C. Ayres, Narure, 1981, 290, 323 26, 3831; J. T. Groves and R. Quinn, 3. Am. 12 C. S. Creaser, A. R. Fernandes and D. C. Ayres,

Chem. I d . , 1988, (IS) , 499 26 C. M. Che, T. F. Lai and K. Y. Wong, Inorg. 13 D. C . Ayres, C. S . Creaser and D. P. Levy in

“Chlorinated Dioxins and Dibemofurans in the 27 Smithson Tennant, Phil. Tram., 1804, 94, 4x1 Total Environment II”, ed. L. K. Keith, C. 28 W. P. Griffith, Platinum Metals Rev., 1974, 18, Rappe and C. Choudhary, Butterworths, Lon- don, 1985, P. 37 29 M. Schrader, Chem. Rev . , 1980, 80, 187

14 Y. Nakano and T. A. Foglia, 3. Am. Oil Chem. 3o H. s. Singh in Ref. 5 , p. 633 31 J. S. M. Wei, I. Marko, J. S. Svendsen, M. G. Soc., 1982, 59, 163

15 G. Green, W. P. Griffith, D. M. Hollinshead and ~ h , E. N. Jacobsen and K. B. Sharpless, 3. S . V. Ley, 3. Chem. Soc., Perkin I , 1984, 681 Am. Chem. Soc., 1989, 1x1, 1123; E. N.

16 A. C. Dengel, R. A. Hudson and W. P. Griffith, Jacobsen, I. Marko, W. S. Mungall, G. Schrijder Tram. Met. Chem., 1985, 10, 98 and K. B. Sharpless, ibid., 1988, 1x0, 1968

sot.* 1985y Io7’ 5790

1987, 26y 2289

(3), 94

Palladium Impedes Radionuclide Pick-Up in Steel The y-emitting isotope, 6oCo, is known to be

the primary offender in causing radioactivity of reactor structural steels. This radionuclide readily incorporates into the various oxides that form on the out-of-core steel surfaces of nuclear reactors operating in coolant environments, at temperatures of approximately 280OC. Thus to lessen the build up of radiation in these structural materials there is a need to eliminate or reduce the incorporation of 6oCo.

Some extremely encouraging experimental results from North America have recently been reported following the exposure of various pretreated austenitic 304 steels to simulated boiling water reactor and pressurised water reactor primary coolant conditions ( I , 2) . Two metallic films and nineteen pre-oxidation treatments were evaluated for their efficacy in reducing 6oCo contamination. Of these treatments, the

deposition of palladium by an electroless technique proved to be particularly effective. Palladium, about 0.6 pm thick, deposited from a standard electroless plating bath closely followed the contours of the steel, and generally filled in major defects on the surface. This layer reduced the corrosion of the stainless steel and so impeded radionuclide pick-up.

Although amorphous nickel-phosphorus films performed reasonably well, it is pointed out that such a system has less attractive characteristics, due to the potential release of the y-emitting * Co isotope from radioactivated nickel.

References I H. Ocken, B. G. Pound and D. H. Lister, nin

2 H. Ocken, C. C. Lin and D. H. Lister, Thin Solid Films, 1989, 171, (2), 313-322

Solid Films, 1989, 171, (2), 323-334


Plenum,

Chem.

Chem. ,

An Advantageous Use of Palladium Compounds in Organic Synthesis THE FORMATION OF CARBON-CARBON BONDS

By M. J. H. Russell Johnson Matthey, Materials Technology Division, Royston

Palladium has a rich organometallic chemistry which has developed over the past twenty-five years. While palladium is not unique in its ability to carry out a wide range of carbon-carbon bond forming reactions, its ver- satility has resulted in an increasing effort being made towards the use of palladium reagents in organic synthesis in academic and industrial research laboratories. This will result in increased industrial applications of these compounds in the organic chemicals sector.

Most of the organic reactions which use palladium compounds involve the interconver- sion of palladium(I1) and palladium(O), that is between the d s and d10 electronic states. This occurs as the reaction sequence usually involves oxidative addition to, and reductive elimination from, the metal centre as necessary steps. Two general types of use have emerged for palladium co-ordination compounds in organic reactions. The first is in catalytic reactions where turnover numbers in excess of 100:1

substrate:palladium are achieved, and the second is as a reagent in stoichiometric reactions. The latter has arisen as a consequence of the facile decomposition of palladium(0) complexes to the metal. For products with a high added value this approach can be cost effective, in that palladium is much cheaper than platinum or rhodium, and high recoveries of palladium can be achieved. Thus the cost of the compound should be regarded as having two components: a manufacturing cost, which in effect is a running cost, and secondly an investment in palladium metal which can, to a large extent, be regarded as a capital investment. It should be noted that in a number of cases it has been possible to change what was initially a stoichiometric reaction into one which is catalytic, by the use of a co-oxidant. The classic example of this is in the Wacker process for

the conversion of ethylene to acetaldehyde. While the redox behaviour of palladium plays

an important role in its relevance to organic synthesis, there are at least three other characteristics which enrich the organic chemistry of palladium.

[a1 The facile rearrangement of trihapto (h’) into monohapto (hl) ally1 complexes, which creates co-ordinative unsaturation at the metal centre and enhances reac- tivity.

Ibl The ability of nucleophile to attack at either metal or ligand sites selectively.

[cl The kinetic lability of palladium-carbon monoxide species which enables carbon monoxide to insert into other palladium- carbon bonds.

This article will address the organic chemistry which can be achieved using palladium complexes, and the nature of the palladium reagents or catalysts.

Palladium compounds are particularly useful for the elaboration of alkenes and alkenic compounds in a number of different ways. The generation of a variety of functional groups from vinyl halides or main group metallovinyllic compounds is illustrated in Figure I.

Arenes can be directly coupled to alkenes containing electron withdrawing groups such


G x

Pd

\ / lu

RCECH 1

\ > -Si-Si-

R -Si -

I

M

‘u SR

t R

Fig. 1 Vinyl halides or main group metallovinyllic compounds may be reacted with palladium(1r) or palladium(0) complexes to generate vinyllic palladium intermediates. These can undergo nucleophilic attack with cyanide or thiolate groups. for example to incorporate functionalities at the vinyllie position. Reaction with alkenes or alkynes can generate conjugated dienes or enelyne systems, and carbonyl species can be formed with carbon monoxide or acyl bromides

that arylation occurs at the least substituted alkenic carbon. The reaction can be made catalytic by using palladium(I1) acetate under an oxygen atmosphere in the presence of copper(I1) acetate or silver acetate. Intramolecular attack of an arene on an alkene can be used in the formation of a fused ring system.

Ph Ph

A variation on this theme is the coupling of aryl organometallics with organic halides (aryl or vinyllic). This route provides a means of

forming 1-aryl-I-alkenes, 1-aryl-2-alkenesy /3-haloethylarenes and /3-arylaldehydes and ketones. It has been used in the synthesis of c h i d styrenyl derivatives as shown in Figure 2

(I), and also in the synthesis of the an- tioestrogenic tamoxifen (2). A practical limita- tion to the utility of this route is the inability to obtain the desired organometallic starting material. A number of organometallics such as those of lithium, magnesium or aluminium are unable to tolerate a range of functionalities on either the organometallic or organic halides. For other base metals, such as boron, zinc or zirconium it is often not possible to synthesise the desired organometallic. The palladium


necessary to use an aeymmetric ligand based on femcene, where one cyclopentadienyl group contains both diphenylphoephino and alkylamino fianctionalities

catalysed coupling of ally1 halides to vinyllic or aryl organotin compounds has shown tolerance to functional groups (ester, nitrile, alcohol or aldehyde).

Pd L*CI 2

OMe B r A C O z E t , \ n-Bu3Sn 7

OMe C02Et -# The catalyst used is Pd(dba),:ZPPh,, where dba is dibenzylideneacetone. In the absence of palladium the reaction is not regioselective, but when palladium is present the cross-coupling takes place in high yield with retention of geometry in the vinyllic partner (3). When the reaction is carried out under a moderate

pressure of carbon monoxide then the carbonyl insertion product is obtained.

A generally useful method of obtaining arylated alkenes is through the palladium catalysed coupling of aryl halides with alkenes. The particular advantages of this system are:

[il The reaction n o d y proceeds in one step with high regioselective and stereoselective control.

[iil The reaction occurs under mild conditions and is not affected by water or air, however if organophosphines are present an inert atmosphere should be used.

[iii] The reaction is tolerant of most functionalities. Recently it has been shown that reasonable rates of reaction can be achieved for the arylation of non-electron deficient alkenes, for


Fig. 2 An asymmetric functionality can be incorporated vinyllic to a atyryl group in a palladium catalysed Grignard coupling reaction. In order to achieve high enantiomeric excesses (typically 95 per cent) it appears to be necessary to use an aeymmetric ligand based on femcene, where one cyclopentadienyl group contains both diphenylphoephino and alkylamino fianctionalities

W

W

.P

h

v

OMe

OC0

2Me +

E

d

Me0

OM

e

1 1 OM

e

Me 0

Fig

. 3

The

ste

pwis

e al

lylic

cou

plin

g of

bif

unct

iona

l mon

omer

s al

low

s th

e co

nstr

ucti

on o

f co

mpl

ex m

olec

ules

bec

ause

of

the

high

reg

io a

nd

ster

eose

lect

ive

cont

rol w

hich

pal

ladi

um(0

) com

plex

es e

xert

on

the

reac

tion

. Thu

s th

e to

tal s

ynth

esis

of c

oenz

yme

QlO

has

been

ach

ieve

d us

ing

tetrakis(triphenylphosphine)palladium(O) a

s th

e ca

taly

st

189 Phrinum Metals Rev., 1989,

example but-3-en-2-01 using palladium acetate as a catalyst in the presence of triethylamine. The amine appears to act as a neutral ligand; it significantly enhances the rate of arylation and also inhibits the formation of palladium metal (4).

An alternative reaction which has attracted a great deal of attention is the incorporation of carbon functionalities at the allylic group through the nucleophilic attack of carbanions on allylic acetates.

This reaction was initially established for relatively simple molecules, but the extremely high regioselective and stereoselective yields which have been achieved has meant that the reaction can be applied sequentially to the synthesis of complex molecules, such as ubi- quinone 10 or coenzyme QIO, as illustrated in Figure 3 (5). Variations in this reaction have made it possible to synthesise juvenile hormone (6), and carbonylation at the allylic position has been used in the preparation of manoalide, Figure 4 (7).

High Selectivity to the Larger Ring Size

Trost, who pioneered the early work on allylic alkylation with Moritani, has applied the procedure to annulation reactions (8). An important feature of the palladium catalysed reaction is that ring closure normally results in high selectivity to the larger ring size, whereas other cyclisation procedures favour the formation of the most stable ring size. Furthermore this procedure is particularly useful for the construction of odd numbered rings, such as (i), and

provides a means of constructing 5 , 7 or 9 membered rings via I2 + 31, 14 + 31 and L6 + 31 cycloadditions, as shown in Figure 5 .

For the construction of macrocycles it is necessary to use high dilution techniques for the homogeneous palladium catalysed reactions. In particular circumstances, however,

this can be avoided by the use of a palladium(0) catalyst which is attached to a macroreticular polymer support containing organophosphine functionalities. Using this system it has been possible to construct a 26 membered macrolide ring (ii), which has antifungal and antibiotic properties.

OTBDPS (ii)

It is also possible to bring about ring closure using oxygen or nitrogen nucleophiles rather than carbon. Isomerisation of an amine nucleophile catalysed by a palladium(0)- bis(dipheny1phosphino)butane complex has been used to bring about cyclisation in the synthesis of inandenin-12-one, a spermidine alkaloid (iii) .

NH2 (iii)

The formation of heterocycles by the use of palladium reagents, typically palladium acetate in acetic acid, is related in some respects to macrocycle synthesis (9). Some illustrations of this are given in Figure 6, where amine and 0x0 groups can be incorporated, as well as carbonyl or amide functions. It is also possible to convert diphenylamine or diphenylether to the corresponding carbazole or oxazole species. These types of bond forming reactions are relevant to the formation of the mitomycin skeleton (iv)

where these compounds are used as antibiotics or anticancer agents. Recently lysergic acid


Me 0,OMe

1 B=NH, NAc,CO,CONH,CONR,O

+co + J@J BujSn

Fig. 4 For th is step in a synthesis of manoalide, a bis(dibenzylideneacetone)palladium triphenylphosphine catalyst is used, and the reaction proceeds under carbon monoxide at a pressure of 3 bars. Carbon monoxide inserts into the allyl-chloride bond and the acyl group couples to the cyclopentadienyl moiety with the elimination of tributyltin- chloride

C02C H3 do2rH3E z o o

Fig. 5 The coupling of molecules with leaving groups such as acetate or trimethylsityl (TMS) at the allylic position with mono, di or trienes permits the formation of 5, 7 or 9 membered rings via [2 + 31, [4 + 31 or [6 + 31 cycloadditions. Odd membered rings are not readily accessible by other routes

Fig. 6 The palladium assisted intramolecular nucleophilic attack of a heteroatom at an alkenic carbon atom permits the formation of heterocycles such as indoles, quinolines and furans


a pharmacologically active ergot alkaloid has been prepared through the intermediate (v), (10).

Bz rls’ Having described the types of reaction that

are possible using palladium reagents, it is worth considering the nature of these reagents.

Palladium(I1) chloride has limited value as a reagent due to its lack of solubility: it is very slightly soluble in water and most organics, but soluble in N,N-dimethyl formamide and hydrochloric acid. As a relatively simple salt, palladium acetate provides an attractive alternative in that it does not possess chloride ions which can cause problems of poisoning and corrosion. In addition it does have a significant solubility in organic solvents such as toluene, acetic acid and alcohols.

Nitrile complexes such as trans-bis(ben- zonitrile)dichloropalladium(II) or trans- bis(acetonitrile)dichloropalladium(II) are soluble in many organic solvents and provide convenient precursors to species of the type [PdCl,L,I, where L is an organophosphine. Thus trans-bis(tripheny1phosphine)dichloropalladium (11), which is commercially available, has found widespread use as a catalyst or reagent, principally because of the wide availability of triphenylphosphine, which has popularised its use as a ligand in combination with a platinum group metal compound. However, the judicious choice of other phosphanes or diphosphanes can lead to significant improvements in selectivity.

Advantages of in situ Catalyst Preparation

The other class of palladium compounds which are widely employed are those of palladium(0) as exemplified, in particular, by tetrakis(triphenylphosphine)palladium(O) . A drawback to the use of this compound is that it

is sensitive to air, and also to heat and light, both in solution and in the solid state. Conse- quently some decomposition can occur on storage, and adequate precautions must be taken if the preformed complex is used. However, it is possible to prepare the complex in situ, one method for this being the reduction of trans-bis(tripheny1phosphine)dichloropalladium(I1) using hydration or a basic alcoholic media in the presence of excess triphenylphosphine, although yields of the palladium(0) product are rarely quantitative. A more convenient precursor is tris(dibenzylideneacetone)dipalIladium(O), Pd (dba) , L (L = dba or solvate). This compound is stable in the solid state and yet in solution the dibenzylideneacetone ligand is labile and is readily displaced by phosphanes to give [PdL,] species (L = phosphane, n = 2-4).

A further feature of this chemistry which has not been utilised to date is that it is possible to modify the solubility of the tris(dibenzylideneacetone)dipalladium(O) by placing substituents on the arene fragment of the ligand .

If an in situ method of catalyst preparation is used then adequate time must be allowed for the desired compound to preform, prior to carrying out the organic transformation. An additional benefit of the in situ method is that it is generally possible to screen a number of catalysts in a cost effective manner, in order to optimise a specific reaction.

Summary and Conclusions This article has dealt mainly with the forma-

tion of carbon-carbon bonds and has excluded other important palladium catalysed reactions such as oxidation and carbonylation for which an extensive literature exists. The regiospecific and stereospecific control which can be exerted in palladium-mediated reactions is impressive, and will undoubtedly result in more industrial applications of palladium in the synthesis of complex organic molecules. It is also anticipated that there will be greater opportunity to use palladium reagents in the synthesis of chiral molecules.


References T. Hayashi, M. Konishi, Y. Okamoto, K. Kabeta 6 Y. Naruse, T. Esaki and H. Yamamoto, and M. Kumada, J. Org. Chem., 1986, 51, (20), 3772 7 S. Katsumura, S. Fujiwara and S. Ism, M. I. Al-Hassan, Synthesis, 1987, (9), 816

1983, 105, (24), 7173 R. Berhaddou, S. Czernecki, G. Ville and A. Zeger, Organometallics, 1988, 7, (12), 2435 E. Keinan and D. Eren, Pure Appl. Chem., 1988, 60, (I), 89

Tetrahedron Lett., 1988, 29, (12), 1417

Tetrahedron Lett., 1988, 29, (IO), 1173

Organic Synthesis”, ed. M. L. H. Green and S. G. Davies, Royal Society, London, 1988, pp. 9-22 and references therein

9 L. S. Hegedus, J. Mol. Catal., 1983, 19, (2), 201 10 S. Cacchi, P. G. Giattini, E. Morera and G. Ortar,

F. K. Sheffy and J. K. Stue, 3. Am. Chem. sot., B. M. Trost, “organometallic &

Tetrahedron Lett., 1988, 29, (25), 3117

Palladium has become established as one of the most widely applicable chemical modifiers in electrothermal atomic absorption spec- trophotometry (ETAAS). Its applications have recently been extended to the determination of lead, cadmium and tin in food slurries.

In ETAAS a volume of sample is introduced into a small furnace-usually a graphite tube- and heated in stages to remove the solvent, decompose the sample matrix and finally produce a cloud of atoms in the central zone of the furnace. These atoms absorb light selectively, permitting the ultra-trace determination of metals. Chemical modifiers are added to the sample solution to avoid the loss of the elements of interest during the decomposition stage.

Palladium as an Aid in Trace Analysis of Food Palladium appears to act by forming compounds, for example Pb,Pd, which are more thermally stable than the base metal alone.

A recent report from the University of Strathclyde, Glasgow, describes the extension of this work to the determination of lead in slurries of freeze-dried foodstuffs (S. Lynch and D. Littlejohn, “Palladium as a Chemical Modifier for the Determination of Lead in Food Slurries by Electrothermal Atomisation Atomic Adsorp- tion Spectrometry”, J. Anal. At. Spectmm., 1989, 4, (2), 157-161). Detection limits of 200 ng/g have been reported. Promising results have also been obtained for cadmium and tin. Palladium appears to have considerable potential in this area. P.W.

Plasma-Enhanced Vapour Deposition of Thin Rhodium Films

Thin films of platinum and of palladium have been prepared successfully by plasma-enhanced chemical vapour deposition, and now the use of this method for the formation of thin rhodium films has been reported (A. Etspiiler and H. Suhr, “Deposition of Thin Rhodium Films by Plasma-Enhanced Chemical Vapor Deposi- tion”, A P P ~ . Ph. A., 1989~48, (4), 373-375). Dicarbonyl-2,~-pentadionato-rhodium(I) was

vapourised from a vessel whose temperature could be changed to achieve the required vapour pressure of the organometallic compound and was then carried into the reaction vessel, through the upper electrode, by a flow of argon or a mixture of argon and hydrogen. The rate of deposition and the properties of the rhodium film depend upon a number of parameters including the temperature of the source, the temperature of the substrate, the

partial pressure of the organometallic, and the hydrogen content of the carrier gas.

It was found that a source temperature of 5o°C gave the best results; increasing the substrate temperature from 3ooC to 15ooC increased the rhodium content of the deposit from 86 to 96 per cent and lowered its resistivity by a factor of four. Hydrogen in the carrier gas also resulted in a further increase in the rhodium content of the film. The lowest resistivity value determined for these thin rhodium films was 23pQcm, compared to 4.51pS2cm for pure bulk rhodium at a temperature of 20OC.

Plasma-enhanced chemical vapour deposition using organometallic is thus a suitable technique for preparing rhodium thin films, especially on three-dimensional and temperature sensitive substrates.


I T. Hayashi, M. Konishi, Y. Okamoto, K. Kabeta and M. Kumada, 3. Org. Chem., 1986, 51, (zo), 3772

z M. I. Al-Hassan, Synthesis, 1987, (9), 816 3 F. K. Sheffy and J. K. Stille, 3. Am. Chem. Soc.,

4 R. Berhaddou, S. Czernecki, G . Ville and A.

5 E. Keinan and D. Eren, Pure Appl. Chem., 1988,

1983, 105, (24), 7173

Zeger, Organometallics, 1988, 7, (12), 2435

60, (I), 89

8 B. M. Trost, “Organometallic Chemistry & Organic Synthesis”, ed. M. L. H. Green and S. G. Davies, Royal Society, London, 1988, pp. 9-22 and references therein

Controlling Motor Vehicle Emissions AN ASSESSMENT OF THE IMPLICATIONS FOR CLIMATE MODIFICATION

By Michael P. Walsh Consultant, Arlington, Virginia, U S A .

For some twenty years this Journal has reported advances in the application of platinum metals catalyst technology for the control of automobile exhaust gases. Thefirst work was directed at reducing atmosphericpollu- tion in Los Angeles, where climatic and topographic conditions, together with a high concentration of automobiles combined to create a clearly perceived problem. Since that time the use of pollution control catalysts for vehicle emission abatement has grown substantially. In Europe, popular concern about the effects ofpollution is now nong translated into legislation to protect the environment, so it is timely to re-examine the existing evidence of the atmospheric changes caused by m t o r vehicles, andfrom that to predict what may happen on a global scale in thefuture. I t is suggested by the author, who was formerly Deputy Assistant Administrator for Mobile Source Air Pollution Control at the U.S. Environmental Protection Agency, that the latest catalyst technology must be applied worldwide, without delay, to prevent further major damage to the environment.

Motor vehicles using petrochemical fuels emit significant quantities of carbon monoxide, unburnt hydrocarbons, nitrogen oxides, fine particles of solids, and lead, each of which in sufficient quantities can cause adverse effects on health and on the environment. Because of the growing number of vehicles in use, and the high levels of emissions from them, serious air pollution problems have become an increasingly common phenomena in modern life. Initially these problems were most apparent in city centres, but recently rivers, lakes and even forests, have also experienced significant degradation. As more and more evidence accumulates of the impact that some of man’s activities are having on the upper atmosphere, so concern is increasing that motor vehicles are contributing not just to local or regional pollution but also to global changes which could modify the climate of the entire planet.

In an effort to minimise the problem of motor vehicle pollution, emission rates from cars have been limited since the 1960s. Starting in 1975,

the pace of control was accelerated with the introduction of oxidation catalytic converters on cars in the United States of America. Now these have been replaced by three-way converters which can lower carbon monoxide, hydrocarbons and nitrogen oxides emissions simultaneously, and increasingly this technology is being applied to vehicles all across the world. Catalytic technology using platinum group metals is now routinely applied to vehicles in Austria, Australia, Canada, the Federal Republic of Germany, Japan, the Netherlands, South Korea, Sweden, Switzerland and the United States. Within the next few years Brazil, Mexico, Taiwan, and most European countries are scheduled to join their ranks.

To date, the primary impetus for these controls has been concern about pollution of the troposphere, which is the lower part of the atmosphere that extends from the surface of the earth to an altitude of between 9 and 17 kilometres. Now, however, evidence shows


that the control of carbon monoxide, hydrocarbons and nitrogen oxides is also necessary to reduce the risk of global warming that could result from changes in the upper atmosphere. Human activity can increase global warming

by changing the chemistry of the atmosphere in two ways: by allowing more rays from the sun to reach the surface of the planet, and by reducing the opportunity for rays to escape from the earth. In the face of “irrefutable evidence” that the chemistry of the upper atmosphere is changing, physical evidence linking these changes to global warming, and “observational evidence” that the earth is in fact warming, political and policy oriented institutions and individuals have increasingly focused their attention on the problem of global warming (I).

The two major human activities that are considered to cause these changes are the combustion of fossil fuels and the release of chlorofluorocarbons. The former leads to the emission of carbon dioxide and other so called “greenhouse gases” which have been shown to be accumulating in the atmosphere in recent years, while the latter can destroy the protective ozone layer which shields the earth from harmful ultraviolet radiation from the sun. Perversely, while the depletion of ozone in the upper atmosphere is the cause of great concern, its formation and accumulation at ground level by the reaction in sunlight of volatile organic compounds, including hydrocarbons, with nitrogen oxides can also be damaging to health, and to plant life.

Several factors have increased the fear regarding global warming and influenced the percep- tion of its severity. First has been the rapid development of a hole in the ozone layer over

either directly or indirectly, each of these has the potential to exacerbate the greenhouse effect (2). Finally, the average global temperature already appears to be increasing, as shown by the fact that four of the warmest years in this century have occurred this decade; worldwide, 1988 appears to have been the hottest year in the last one hundred and thirty, during which detailed records have been kept (3). In the north-eastem U.S.A., at one point, there were over 40 consecutive days with temperatures in excess of 3zoC, a factor which contributed to the highest tropospheric ozone levels in a decade (4).

While the global temperature cycle is not fully understood and can be influenced by many factors, the combination of factors noted above has led highly reputable scientists to conclude that global warming is already occurring as a result of the greenhouse effect (5,6). For example, Dr. James Hansen, the head of the Na- tional Aeronautics and Space Administration’s Goddard Institute for Space Studies, told a Senate subcommittee that it is “time to stop waMing so much and say that the evidence is pretty strong that the greenhouse effect is here” (7). Others who feel that the linkage between the greenhouse gases and global warming is still tenuous, none the less seem to be leaning toward some precautionary controls at this time because the potential adverse impact could be so severe. This latter view is reinforced by the lessons of the ozone hole. Clearly we do not understand fully the phenomena but once it starts, if it starts, it may proceed much more quickly than we currently anticipate and lead to results we cannot predict. As recently noted in Science:

the Antarctic, which shows that human activity is actually causing modifications to the upper atmosphere, and that once such modifications begm they can proceed at a rapid and not fully understood rate. Indeed, new evidence suggests the presence of a similar but smaller hole over the Arctic. Second there is clear evidence that global atmospheric concentrations of carbon dioxide, methane, nitrous oxide, carbon monoxide and other gases are increasing, and 1

“the possibility that a considerably larger, though less likely, temperature rise presents the greater risk remains ignored. The latter eventuality is more to be feared, principally because of the high cost of its effects, the draconian and expensive steps needed to avert it, and the time required, first, to obtain global agreement on the need to act, and then to transmute world energy production into a non fossil-fuel-using system.” (8)

Many observers now agree that motor rehicles already play a significant role in the


Pollutanl Total amount

-.

Nitrogen oxides 36,019 Hydrocarbons 33,869 Carbon monoxide 119,148

climate modification problem, and have the potential to play an even greater role in the future. The purpose of this analysis is to examine that role and its likely future direction. First, an assessment will be made of the important greenhouse gases and the current significance of vehicle emissions. Then, historical and likely future trends in vehicles and their use will be summarised. Finally, the overdl effect of vehicles and emission control technologies on future climate modification will be assessed.

Vehicle emissions

Amount Percentage

17,012 47 13,239 39 78,227 66

The Role of the Motor Vehicle in Climate Modifkation Important Greenhouse Gases

Important greenhouse gases include carbon dioxide, some of the chlorofluorocarbons (CFC-I I , CFC-12), methane, nitrous oxide, ozone and the compounds which cause ground level ozone to form, hydrocarbons, and the other oxides of nitrogen. On a global scale, each of these gases has been increasing in recent years. As noted in a recent report:

“The concentrations of halocarbons, methane, nitrous oxide (N,O), odd nitrogen and carbon monoxide appear to be increasing at present on a global basis, by 5% per year for CFC-II and CFC-12, 7% per year for CH,CCI,, I percent a year for CH,, o.z%per year for N,Oand I to 2% per year for CO”. (9)

Concentrations of ground level ozone are increasing, and stratospheric ozone is being destroyed globally. During the Antarctic spring a “hole” the size of North America is depleted of ozone and, at certain altitudes, is destroyed almost completely because of man-made

chemicals (10). Researchers who recently re- analysed a set of European data on tropospheric ozone concentrations from the turn of the century concluded that ozone concentrations had doubled over the last 100 years ( I I ) . One com- mentator described the finding “as remarkable as the observation of a hole in the stratospheric ozone layer over Antarctica and potentially is just as consequential” (12). An analysis of several sites indicates that tropospheric ozone background levels are increasing at a rate of I

to 3 per cent per year, with overall nitrogen oxides increases being the controlling factor (13).

Likely Effects of Climate Modification Over the next fifty years, increasing concen-

trations of tropospheric ozone and other greenhouse gases are projected to result in an increase in the global average temperature of between 1.5 and 4.5OC. Changes likely to hc- company this temperature increase include stratospheric cooling, an increase in global mean precipitation, reduction of sea ice, polar winter surface warming, summer continental dryness, precipitation increase in high latitudes, and a rise in global mean sea level. Most of these changes should occur gradually. The U. S. Environmental Protection Agency (E.P.A.) has recently estimated that average sea levels will rise 5 to 15 inches above current levels by the year 2025, if events develop as anticipated (14); however, the Antarctic ozone hole experience reinforces the anxiety that is associated with any such significant and poorly understood phenomena, because of the risk that chemical modifications once initiated may


Motor Vehicle Contributions to O.E.C.D. Pollutant Emissions in Year 1980 (1000 tons)

proceed at a faster rate than is generally anticipated at present.

Complex Inter-Relationships between Gases

Some of the previously mentioned compounds react with each other in ways which have been understood only recently. For example, hydroxyl radicals (OH), which scavenge many anthropogenic and natural trace gases from the atmosphere, are themselves removed by carbon monoxide (I 5, I 6). This was summarised by Ramanathan in a recent Science article:

“The highly reactive OH is the primary sink for many tropospheric gases and pollutants including O , , CH,, CO, and NO. Hence, increases in CH,, such as those during the last century [135% increase] could have caused a substantial (20 to 40Y0) reduction in OH, which in turn, could cause an increase in tropospheric 0) by as much as 20%. Since CH, oxidation leads to the formation of H,O, an increase in CH,, an important greenhouse gas, can lead to an increase in H,O in the stratosphere. Likewise, an increase in the CO concentration can tie up more OH in the oxidation of CO. Thus, through chemical reactions, an increase in either a radiatively active gas such as CH, or even a radiatively inactive gas such as CO can increase the concentration of several important greenhouse gases.” (2)

Thus carbon monoxide emissions are very important for climate modification. This point was reinforced by Dr. Gordon MacDonald at a recent World Resources Institute Symposium:

“Carbon monoxide could thus be indirectly responsible for increasing greenhouse warming by 20 to 40% through raising the levels of methane and ozone. . . . Carbon monoxide participates in the formation of ozone, and also in the destruction of hydroxyl radicals, which are principal sinks for ozone and methane greenhouse gases. Because carbon monoxide reacts rapidly with hydroxyl, increased levels of carbon monoxide will lead to higher regional concentrations of ozone and methane. Measures to reduce carbon monoxide emissions will assist in controlling greenhouse warming.” (17)

This is especially significant in view of the evidence that global carbon monoxide levels are now also increasing. As recently noted by Khalil and Rasmussen:

“the average tropospheric concentration of CO is increasing at between 0.8% and 1.4% per year,

depending on the method used to estimate the trend, and the 9% confidence limits of the various estimates range between 0.5% and 2.0%

per year.” (18)

Motor Vehicles Emit Many of These Gases

Motor vehicles generate more air pollution than any other single human activity. Greenhouse gases emitted by, or attributable to, motor vehicles include chlorofluorocarbons, carbon dioxide, nitrous oxide, methane, and the precursors to ground level ozone, namely, hydrocarbons and the other nitrogen oxides (19). Chlorofluorocarbons. These are the most potent greenhouse gases and are now responsible for about 15 to 20 per cent of the total global warming effect (2). About 40 per cent of the United States production of chlorofluorocarbons and 30 per cent of European production is devoted to air conditioning and refrigeration. Mobile air conditioning accounted for 56,500 metric tons of chlorofluorocarbons-28 per cent of the chlorofluorocarbons used for refrigeration in the United States, or about 13 per cent of total production. In contrast, home refrigerators accounted for only 3,800 metric tons (20). Thus, approximately one of every eight pounds of chlorofluorocarbons manufactured in the U.S.A. is used, and emitted, by motor vehicles. Chlorofluorocarbons are also used as a blowing agent in the production of seating and other foamed products but th is is a considerably smaller vehicular use. Carbon dioxide is the other major greenhouse gas. A single tank of gasoline produces between 300 and 400 pounds of carbon dioxide when burned. Motor vehicles emit almost 15 per cent of the world’s output; in the U.S.A. motor vehicles are responsible for about 25 per cent of the total carbon dioxide emissions (19). Carbon monoxide, hydrocarbons and nitrogen oxides. In 1985, in the U.S.A., transportation sources were responsible for 70 per cent of the carbon monoxide, 45 per cent of the nitrogen oxides, and 34 per cent of the hydrocarbons. For transportation sources other than highway vehicles, that is air, rail and marine transport, the U.S. Congressional

Platinum Metals Rev. , 1989, 33, (4) 197

Office of Technology Assessment (O.T.A.) recently concluded that mobile sources were ac-

nitrogen oxide control is also necessary. A prominent researcher in this field has noted that:

mdY for 4’ per Cent Of total “Recent research from our group nationwide volatile ComPunds indicate there is a critical need to consider con- (V.O.C.). As illustrated in Figure I , the only other major source category which this Office found to be responsible for amounts approx- imating to those from mobile sources in 1985 was organic solvent evaporation (21). Based on recent preliminary data regarding evaporative “running losses”, the hydrocarbon contribution from vehicles may actually be substantially higher; running losses could exceed I. 5 grams per mile (22).

Motor vehicles also dominate the emissions inventories of most European countries. The Organisation for Economic Co-operation and Development (O.E.C.D.) recently noted that:

“The primary source category responsible for most NOx emissions is road transportation roughly between 50 and 70 per cent. . . . Mobile sources, mainly road traffic, produce around 50 per cent of anthropogenic VOC emissions, therefore Constituting the largest man-made VOC source category in all European OECD countries.” (23)

Beyond the U.S.A. and Europe, the Table shows that, for countries belonging to the O.E.C.D. as a whole, motor vehicles are the dominant source of carbon monoxide, oxides of nitrogen, and hydrocarbons (24).

These Pollutants Cause Other Adverse Effects

While climate modification is the primary focus of t h i s study, it is important to note that many of the same pollutants which cause or contribute to that problem, also contribute substantially to adverse health effects in many individuals, in addition to harming terrestrial and aquatic ecosystems, causing crop damage, and impairing visibility. Some of these other effects will be described below. Tropospheric Ozone. Photochemical smog results from chemical reactions involving both hydrocarbons and nitrogen oxides in the presence of sunlight. While historically the major strategy for reducing smog has focused on tight restrictions on hydrocarbon emissions,

trols on both nitrogen oxides and reactive hydrocarbons if overall oxidant levels are to be lowered. . . . A critical implication of these findings is that without controls on nitrogen oxides the current control policies will simply change the urban ozone problem into a regional scale one.” (25)

The ozone problem is a special concern. First, the problem is widespread and pervasive, and appears likely to be a long term problem in many areas of the world unless further significant controls are implemented. For example, almost 80 million Americans currently reside in areas where the amount of ozone exceeds the current air quality standard (26, 27); many of these individuals suffer eye irritation, cough and chest discomfort, headaches, upper respiratory illness, increased asthma attacks, and reduced pulmonary function as a result of the ozone levels.

In addition, the current air quality standard tends to understate the health effects. For example, as noted by E.P.A. Administrator Lee Thomas, new studies indicate:

“that elevated ozone concentrations occurring on some days during the hot summers in many of our urban areas may reduce lung function, not only for people with preexisting respiratory problems, but even for people in good health. This reduction in lung function may be accompanied by symp- tomatic effects such as chest pain and shortness of breath. Observed effects from exposures of I to z hours with heavy exercise include measurable reductions in normal lung function in a portion (15-30 per cent) of the healthy population that is particularly sensitive to ozone.” (26)

Other studies presented at the recent U.S.- Dutch Symposium on ozone indicate that healthy young children can suffer adverse effects from exposure to ozone at levels below the current air quality standard (28). Numerous studies have also demonstrated that photochemical pollutants inflict damage on forest ecosystems and seriously affect the growth of certain crops. (29)

It is important to note that global warming may have a significant impact on local ozone air


t u d y responsible almost oreanic

Mobile sources Air, rail , marine

Organic solvent evaporation industrial

Gas station evaporation

Solid waste disposal

Chemical manufacture

Petroleum industry

Other industries b Other fuel combustion

Miscellaneous

Home fuel consumption Most not generated during ozone season

0 10 2 0 30 40 VOLATILE ORGANIC COMPOUND EMISSIONS, per cent of total

Fig. 1 Data from a 1988 study carried out by the Congressional Office of Technology Assessment show that in the U.S.A. mobile sources are responsible for almost 40 per cent of all volatile organic compounds emitted in that country. Organic solvent evaporation from miscellaneous stationary sources formed the second largest category

pollution episodes. As recently pointed out by the American Lung Association:

“the increase in ultraviolet B radiation resulting from even a moderate loss in the total ozone col- umn can be expected to result in a siffnificant increase in peak ground based ozone levels.” . . . “these high peaks will occur earlier in the day and closer to the populous urban areas in comparison to current experience, resulting in a significant, though quantitatively unspecified, increase in the number of people exposed to these high peaks.” (30)

Furthermore, tropospheric ozone is a greenhouse gas. Ozone absorbs infrared radiation and increased ozone concentrations in the troposphere will then contribute to climate modification. Carbon Monoxide. Exposure to carbon monoxide results almost entirely from motor vehicle emissions, although in some localised areas, wood burning stoves also significantly affect carbon monoxide levels. While there has been progress in reducing ambient carbon monoxide levels across Europe, Japan and the United States, the problem is far from solved. For example, approximately 85 major metropolitan areas in the U.S.A., with a total population approaching 30 million, currently exceed the carbon monoxide air quality stan-

dard. In fact, E.P.A. Administrator Lee Thomas indicated in Congressional testimony that as many as 15 areas in the United States may have intermittent carbon monoxide problems that could prevent attainment of this standard for many years (26). This problem is important because of the

clear evidence relating carbon monoxide exposure to adverse health effects. For example, in a recent assessment conducted under the auspices of the Health Effects Institute, it was concluded that:

“These findings demonstrate that low levels of COHb produce significant effects on cardiac function during exercise in subjects with coronary artery disease.” (31)

Further, in another recent study of tunnel workers in New York City, the authors noted:

“Given the magnitude of the effect that we have observed for a very prevalent cause of death, exposure to vehicular exhaust, more specifically to CO, in combination with underlying heart disease or other cardiovascular risk factors could be responsible for a very large number of preventable deaths.” (32)

In addition, as noted earlier, recent evidence indicates that carbon monoxide may contribute to elevated levels of tropospheric ozone (17).

Plotinurn Metals Rev., 1989, 33, (4) 199

Oxides of Nitrogen. A variety of adverse health and environmental effects are produced by nitrogen oxides emissions from vehicles and other sources. These emissions also react chemically with other pollutants to form ozone and other highly toxic pollutants. Next to sulphur dioxide, nitrogen oxides emissions are the most prominent pollutants contributing to acidic deposition.

Exposure to nitrogen dioxide emissions is linked with increased susceptibility to respiratory infection, increased airway resistance in asthmatics, and decreased pulmonary function (33). While the annual average national air quality standard is currently attained in most areas of the U.S.A., short term exposures to nitrogen dioxide have resulted in a wide range of respiratory problems in school children, the most common being coughs, runny noses and sore throats, as well as increased sensitivity to bronchoconstrictors by asthmatics (34, 35).

The World Health Organisation concluded that a maximum I hour exposure of 190 to 320 micrograms per cubic metre (0.10-0.17 ppm) should be consistent with the protection of public health, and that this exposure should not be exceeded more than once per month. The State of California has also adopted a short term nitrogen dioxide standard, 0.25 ppm averaged over one hour, to protect public health.

Oxides of nitrogen have also been shown to affect vegetation adversely. Some scientists believe that these oxides are significant contributors to the dying forests that are seen throughout central Europe (36). This adverse effect is even more pronounced when nitrogen dioxide and sulphur dioxide occur simultaneously. Furthermore, nitrogen dioxide has been found to cause deleterious effects on a wide variety of materials, including textile dyes and fabrics, plastics and rubber, and is responsible for a portion of the brownish colorations in polluted air or smog.

Acid deposition results from the chemical transformation and transport of sulphur dioxide and nitrogen oxides. The latter emissions are responsible for approximately one-third of

the acidity of rainfall. Recent evidence indicates that the role of nitrogen oxides may be of increasing significance with regard to this problem:

“Measurements of the nitrate to sulphate ratio in the atmospheric aerosol in southern England have shown a steady increase since 1954. The nitrate content of precipitation averaged over the entire European Air Chemistry Network has steadily increased over the period 1955 to 1979. The nitrate levels in ice cores from South Greenland have continued to increase steeply from 1975 to 1984, whilst sulphate has remained relatively constant since 1968. The ‘Thousand Lake Survey’ in Nor- way has recently revealed a doubling in the nitrate concentration of 305 lakes over the period 1974-1975 to 1986, despite little change in pH and sulphate.” (37)

Several plans to control acid deposition have targeted on reductions in nitrogen oxides emissions, in addition to substantial reductions in sulphur dioxide. The participating countries at the 1985 International Conference of Ministers on Acid Rain undertook to “take measures to decrease effectively the total annual emissions of nitrogen oxides from stationary and mobile sources as soon as possible.” (38)

Conclusions: Vehicle Emissions and Climatic Modifications

Emissions of hydrocarbons, carbon monoxide and nitrogen oxides from motor vehicles, therefore, can be seen as a major source not only of climate modification but also of adverse health and other environmental effects resulting from ground level pollution. In addition, tropospheric pollution and climate modification have been found to be directly linked by a variety of mechanisms. To deal with these problems in a co-ordinated manner re- quires the minimisation of carbon monoxide, carbon dioxide, hydrocarbons , nitrogen oxides and chlorofluorocarbons.

On a global scale, total emissions of these pollutants depend on the number of vehicles in use and their emission rates. In turn, their actual emissions rates depend on their fuel efficiency and their use of available control technologies.

Vehicle pollution control devices and fuel


150 Fig. 2 From a 1960 1

base line, the world population is expected to double by the year 2000. As shown here, this increase will be due largely to rapid population growth in Asia and South America

n

E s . _

t U

1985 CALENDAR YEAR

- a w

2000

efficiency improvements can reduce the greenhouse and other adverse effects which result from these vehicles. However, the continued growth both in the number of vehicles and their use can overwhelm the potential benefits of these technological gains. Unless this growth is constrained, global pollution will continue to increase, many areas which currently have relatively clean environments will deteriorate, and the few areas which have made progress will see some of these gains eroded.

A larger population and greater economic ac-

tivity in the future holds the potential to increase the problem. Whereas the number of people in Europe and the U.S.A. is growing slowly, the global population is expected to double (compared to 1960 levels) by the year 2000, driven by more than a doubling in Asia and an almost 150 per cent increase in South America, see Figure 2. As well as the overall growth in population, an increasing portion of the people in Asia and South America are mov- ing to cities, thus further increasing the global urban population, see Figure 3. One result

n g .r

z l $60 A L u

z n

P 240 3

2 Fig. 3 The continuing movement of people from 2 the countryside to cities E 2 O increases the global urban population even more, and has the potential to increase the problems of 0

5

pollution 1960

w 1 CALENDAR YEAR

Platinum Metab Rev., 1989, 33, (4) 201

Fig. 4 Historic trends in vehicle registrations worldwide show that, with the possible exception of World War II, there has been a steady increase in the number of vehicles. Since 1950 the average annual growth rate for cars has been 5.9 per cent and for trucks and buses 5.6 per cent

CALENDAR YEAR

is that global automobile production and use are projected to continue to grow substantially over the next several decades.

The next sections will examine both the historical and likely future prospects for the number of vehicles and their use.

World Motor Vehicle Registrations Overall Hietorical Trends

The overall trends in vehicle registrations around the world since 1930 are shown in Figure 4. Since 1950, the average annual growth rate for cars has been 5.9 per cent; for trucks and buses, it has been only slightly less at 5.6 per cent per year. Most recently the trends have remained quite high, but the number of commercial vehicles has actually risen more rapidly than cars. For example, since 1970, annual car growth has averaged 4.7 per cent per year while truck and bus registrations averaged 5 . I per cent per year. Overall, as a result of this growth, the total worldwide vehicle count in 1985 was just under 500 million, with the number of cars approaching 400 million.

Recent Trends in Various Areas With regard to the global car population,

Figure 5 shows that Europe and North America each have slightly more than one third of the

world’s total, with the remainder divided between Asia, South America, Oceania and Africa, in that order. With regard to trucks and buses, on the other hand, North America has about 40 per cent followed closely by Asia and then Europe.

It seems important to emphasise the dominant role of North America and Western Europe as potential vehicle markets. While the percentage growth in vehicle production is quite high in other countries, and to a lesser extent the percentage growth in vehicle registrations in those countries is also relatively large, the “highly industrialised” Western markets are so big that they dominate the world, and they are likely to continue to do so for the foreseeable future.

The result of this is that, to a large extent, vehicle specifications in these highly industrialised countries will have a significant impact on vehicle characteristics in other areas. For example, it seems likely that increased stringency of emissions or fuel economy requirements in the highly industrialised West would lead to similar requirements in other vehicle markets, especially those where vehicle production is increasing with a view to expor- ting to the highly industrialised markets. The converse, of course, is also true-weak requirements in the highly industrialised areas will probably result in weak controls in the

Platinum Metah Rev., 1989, 33, (4) 202

Fig. 6 The vehicles per 600- capita for Merent geographic regions bet- 5oo ween 1974 and 1985 are shown. The numbers for 8 the U.S.A., which has the 2 4oo- greatest per capita vehicle population, are still increasing s 300-

L

1975

/ U.S.A.

1980

Y E A R S

In W

g mo- r W

100-

198

/

- --- ----- -- ----- W o r l d _ _ _ _ _ _ - - ------- - B r a z i l - U.S.S.R.

Fig. 7 The projections uI

for the numbers of ,f 1

vehicles worldwide are .: based on linear regres- . sions, and show that the o,B growth expected between 3 1985 and 2030 for both ' trucks and cars should in- $ o.6 crease at an average rate of about 2.5 per cent per 9 year V Z 0.4

n

w CARS

TRUCKS t, 0.2 w

0 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

CALENDAR YEAR


Fig. 5 In 1985 North America and Europe each had in exceee of one third of the global car population, followed by Asia and then South America. For trucks and bueee, North America was the leader, followed by Asia and then Europe

developing areas. It also appears that much of the vehicle population growth in some rapidly industrialising, developing countries comes from imports of used vehicles from highly industrialised areas. Thus, fundamental designs which are either high or low in emissions or fuel consumption are perpetuated, and can increase or decrease overall emissions and fuel consumption in these rapidly industrialising countries.

Vehicle Registrations Per Capita As the above figures showed, the number of

vehicles in the world has been growing faster than the population. Over the last decade the per capita car population has increased in every corner of the world. This is illustrated in Figure 6, which shows the trends for selected countries and Western Europe. Even the U.S.A., which already has a much greater per capita vehicle population by far than any other area of the world, continues to increase, indicating that there is not a natural limit, or at least that it has not yet been reached.

Vehicle Projections Projections of vehicle population and use

have been developed based on historical trends, patterns of population, and discussions with ex- perts in various countries (39-75). Such projections are, of course, inherently uncertain

because of the inability to predict factors such as international crises, prolonged economic downturns, and oil embargoes.

Two methodologies have been used to project the future vehicle fleet. Conservatively, vehicle growth can be expected to follow historical trends, as reflected by a straight linear regres- sion. As shown in Figure 7, this indicates a global vehicle population approaching one thousand million by the year 2030. If, on the other hand, per capita trends are regressed, and then multiplied by population estimates, the global vehicle population would tend to be even higher, as shown in Figure 8. Overall each scenario indicates that the global vehicle populations will increase at an average rate of about 2.5 per cent per year, over the timeframe investigated; in individual countries, particularly in Asia and Latin America, vehicle numbers are growing at an even faster rate.

Possible Limits To Growth It is important to emhasise that making

predictions forty or fifty years into the future is fraught with uncertainty. Will war or economic crises intervene? How will individuals react to increased congestion and pollution? When will the world really run out of economically usable Oil?

It seems virtually certain that one or another

1401 120

1985 2000 2005 2010 2015 20 2025 2030 CALENDAR YEAR

Fig. 8 The global car population might be even higher if the per capita trends are regressed and then multiplied by population estimates

0 CARS PER 1000

POPULATION x 100.000.000

CARS x 10,00O,OC€I


of these or many other potential eventualities will intervene at some time in the future. However, with the possible exception of World War 11, none of the events of the last fifty years has slowed the steady increase in the global vehicle population. For example, some would argue that future vehicle growth will be constrained by the increased congestion which would inevitably result. However, past experience in the U.S.A. has not borne this out. This is well illustrated by the recent events in New York City, as summarised in the article, “New York Rush Hours Grow Earlier and Later”, (76). Most people would agree that during the morning and evening rush hours, Manhattan is one of the most congested urban centres in the United States, if not the world. Data shows that in spite of the congestion, peak hour traffic into and out of Manhattan has increased about one per cent per year from 1981 to 1986; further, it has increased at a much higher rate during the early morning hours and late evening hours, just before and after the peaks. Congestion appears to spread traffic out over a larger area and for a longer time, rather than to stop its growth. As a result, the New York Metropolitan Area continues to grow.

Projecting Total Mobile Source Emissions Mobile 3 Emissions Model

In the 1970s the U.S. Environmental Protec- tion Agency developed a computer modelling system for predicting the effect of improvements in emission control on motor vehicles. The model used data from tests performed on vehicles taken at random from the in-use fleet to assess the effectiveness of the control technology. This model has undergone a number of significant changes over the last ten years to account for innovations in technology, improved understanding of the emissions process, and changes in assumption about the in-use fleet composition.

Based on available data from sources in various countries, emissions factors for vehicles were developed and used to customise the model known as Mobile 3. This was then used

to calculate overall emissions under appropriate driving conditions for each case study.

Calculating Emissions The emissions rates from the modified

Mobile 3 were combined with the vehicle growth projections to estimate future emissions by year. To carry out the calculations, the world vehicle population was subdivided into several vehicle categories according to the level of emission control which was judged likely to apply at a given point in time:

I) U.S. standards 2) Stockholm Group standards 3) Common Market standards 4) East Europe standards 5 ) Gulf Coast Council 6) No requirements Vehicles in the first category are assumed to

meet the currently adopted U.S. standards, or the approximate technological equivalent, for all categories of vehicles. The second group, the Stockholm group has U.S. standards for cars but somewhat more lenient requirements for heavy duty vehicles. In the third case, all vehicles are assumed to adopt the Common Market standards for all vehicle categories; the so called Luxembourg standards were assumed to go into effect on time in all Common Market countries and with small cars (with engines less than 1.4 litres in size) meeting the same standards as medium sized cars. Eastern Block countries are assumed to adopt the same standards as the Common Market but with a three year delay. The Gulf Coast countries were assumed to adopt U.S. vehicle standards but with a delay until 1995. The final category is self explanatory.

It should be clear from the above summary that there are two different sets of requirements in the world today. First, the U.S. type, which effectively results in the use of three-way catalysts, using primarily platinum, palladium and rhodium, with closed loop electronic feed back systems for gasoline fuelled light duty vehicles. These requirements, giving rise to so called environmentally friendly vehicles, have been adopted by several countries


1985 Stockhdm Qorp d&L

(3.4%)

f l (8.4%)

canmn w*t

2000

Fig. 9 The percentage distributions of the six emissions standards adopted for cars throughout the world are shown for years 1985, 2000 and 2030. The projected car populations, of 375 million, 489 million and 839 million, respectively, are based on those shown in Figure 7. It is estimated that by 2030 the most stringent U.S. standards will only be in force in 49.6 per cent of all cars

around the world. Secondly, the Common Market requirements (“mixed”) which are much less effective at present but appear to be rapidly approaching U. S. catalyst technology.

Global Carbon Monoxide, Hydrocarbons and Nitrogen Oxides Emissions Projections

Over a period of time, the growing global vehicle population has become grouped according to several emissions standards’ categories, as summarised in Figures 9 and 10.

Results for carbon monoxide, hydrocarbons and nitrogen oxides are summarised in the three parts of Figure 1 1 . They show that all three pollutants are likely to increase in the future, despite the adoption of all the restrictions that were planned during early 1989*. Even these estimates are optimistic because they do not account for the increased emissions likely to occur as a result of increased traffic congestion.

An additional scenario was also added which assumed that by the year 2030, all vehicles around the world would be equipped with the


Fig. 1 0 For all vehic..-s throughout the world their percentage distributions among the various emissions standards are shown for yeare 1985, 2000 and 2030, when the total populations are projected to be 489 million, 640 million and 1106 million, respectively. By 2030 only 50.5 per cent of all vehicles should adhere to the stringent U.S. standard

* Footnote As this article was going to press, in a dramatic

reversal, the European Council of Environmental Ministers decided to significantly strengthen the Luxembourg compromise. Details are st i l l being developed regarding such questions as incorporation of high speed driving conditions and in-use durability requirements. Depending on how these issues are resolved, the overall emission control of carbon monoxide, hydrocarbons and nitrogen oxides from cars in the Common Market could approximate to that in the United States. In any event, it appears likely that platinum-based three-way catalytic converters will be used on most, if not all, new cars in the European Community by the year 1993.

same state-of-the-art-including platinum based catalytic converters-emission controls as installed on vehicles in the U.S.A. These results, displayed on the three parts of Figure I I , show that this alternative has the potential to offset the global vehicle population growth. In other words, if it were possible to introduce state-of- the-art emissions controls across the entire planet, it might be possible to start to reduce global emissions of carbon monoxide, hydrocarbons and nitrogen oxides from the vehicle population, simultaneously absorbing

Platinum MetaLF Rev., 1989, 33, (4) 207

1986 2000 2030 CALENDAR YEAR


' i? 2 60 YI

f 0

0 4 0

VI W

e 3 z 2o

P 0

- z o


ADOPTED REQUIREMENT

REASONABLE REQUIREMENT

U S STANDARDS

Fig. 11 The global emissions of carbon monoxide, hydrocarbons and nitrogen oxides by vehicles in years 1985, 2000 and 2030 indicate increasing amounts of these pollutants, based on presently adopted requirements, and on reasonable requirements when all standards are in operation. However, the introduction of catalytic converters, as used to meet current U.S. standards, has the potential to offset the adverse effects caused by the increase in global vehicle population

approximately 2 per cent annual growth in vehicle miles travelled.

As noted earlier, climate modifications can result from vehicle emissions other than carbon monoxide, hydrocarbons and nitrogen oxides. Other important pollutants include carbon dioxide, the subject of the next two sections.

Fuel Consumption and Carbon Dioxide Emissions Fuel Consumption Worldwide

The degree of control of fuel consumption ex- ercised by Governments varies throughout the world. In the U.S.A. and Japan, improvements in fuel consumption are being enforced. In Europe, government control is limited to mandatory publication of vehicle fuel consumption data in only France and the United Kingdom; additionally, voluntary commitments have been made by motor manufacturers in several countries for improvements in fuel consumption. Other measures which have been taken by some countries to reduce fuel consumption include lower speed limits, and higher taxes on vehicles with high fuel consumption.

The U.S.A. Fuel Consumption Experience

It is shown in Figure IZ that automobile cor- porate average fuel economy figure (C.A.F.E.) rose during the 1970s but has remained fairly flat since the early 1980s. It is important to note that during the 1970s when emissions standards were substantially tightened, average miles per gallon improved significantly. This observation is true even if fuel economy improvements due to vehicle weight reductions are not included. However, during the 1980s when vehicle emission standards have generally stabilised, fuel economy gains have been minimal. Further, without the stimulus of regulatory requirements or market incentives due to higher fuel prices, manufacturers quickly reverted to historical patterns of competing on the basis of horsepower and acceleration rather than on fuel economy or emissions. The lesson seems to be that, just as with emissions, stringent regula- tion is the surest path to the desired goal.


Fig. 12 The average miles i per gallon travelled for U.S. care and light trucks has increased over the last 14 ,: *' years, but has levelled off E recently. During the 1 9 7 0 s 5 as emission standards were tightened there was an im- f

provement in the average E miles per gallon travelled

"- 'a-

''; "- "-

" - 2 1 -

23 ~

17.

with a yearly improvement of 1 per cent in the miles per ' 1 -

gallon travelled the carbon

f~ 1975 1978 1981 1984 1987

z MODEL YEAR

On a worldwide basis very little if any fuel efficiency improvement is occurring at present. The governmental push of the late 1970s and early 1980s has stalled, and market competition now appears to be focused primarily on performance improvements rather than fuel economy gains.

The significance of this for global carbon dioxide is illustrated in Figure 13. In effect, even with only a 2 per cent annual growth worldwide in vehicle miles travelled, motor vehicle carbon dioxide emissions will drastically increase over the next forty to fifty years. Modest efficiency improvements on the scale of

one per cent per annum would barely reduce this growth.

Conclusions Emissions of hydrocarbons, carbon monox-

ide and nitrogen oxides from motor vehicles are a major source of climate modification, as well as of adverse health and other environmental effects resulting from ground level pollution. In addition, tropospheric pollution and climate modification have been found to be directly linked by a variety of mechanisms. To deal with these problems in a co-ordinated fashion re- quires the minimisation of carbon monoxide,


Fig. 13 Drastic increases in the amount of global carbon dioxide emissions occur with an assumed 2 per cent annual growth worldwide in vehicle miles travelled. Even with a yearly improvement of 1 per cent in the miles per gallon travelled the carbon dioxide emissions are still enormous

carbon dioxide, hydrocarbons, nitrogen oxides and also chlorofluorocarbons.

On a global scale, total emissions of these pollutants depend on the number of vehicles in use and their emissions rates. In turn, actual vehicle emissions rates depend on their fuel efficiency and their use of available control technologies, such as platinum based catalytic converters.

Vehicle pollution controls and fuel efficiency improvements can reduce the greenhouse and other adverse effects which result from these vehicles.

The damage caused by vehicular pollutants is no longer doubted and is increasing on a global basis. Increases in the number of vehicles and the number of vehicle miles travelled is over- whelming the reductions which have been achieved to date, although almost fify per cent of all new cars produced this year around the world are equipped with state-of-the-art, including catalytic converters, emissions controls.

The Common Market countries of Europe have stood out as the slowest industrialised area to implement state-of-the-art, including catalytic converters, requirements. Accepting that further damage to the environment would result from weak motor vehicle emissions requirements, the Common Market countries of Europe have now agreed to substantially tighten standards. Depending on the resolution of such issues as the incorporation of high speed

driving conditions and in-use durability requirements, the overall degree of control could approximate that in the U.S.A. Adoption of the most advanced emissions controls throughout the U.S.A. and Europe, coupled with enhanced inspection and maintenance programmes to maximise the effectiveness of these controls, has the potential to substantially lower carbon monoxide, hydrocarbons and nitrogen oxides emissions in these areas compared to the situation that would otherwise result. If these controls could be applied to all vehicles throughout the world, the projected growth of global emissions of these pollutants would be restrained, at least throughout the first quarter of the next century.

Experience gained during the 1970s and 1980s in the U.S.A. and Japan suggests that the dual goals of low emissions of carbon monoxide, hydrocarbons and nitrogen oxides, and improved energy efficiency (and therefore lower carbon dioxide) are not only compatible but are mutually reinforcing. However, significant gains in either area are dependent on forceful government requirements. Mandatory fuel efficiency standards throughout the world are feasible and necessary to slow the growth in carbon dioxide emissions. In conjunction with stringent carbon monoxide, hydrocarbons and nitrogen oxides requirements, the potential exists to offset not only the global impacts of expected vehicle growth over the next half century but also to start to reduce emissions.

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34 J. Orehek, J. P. Massari, P. Gayrard, C. Grimaud and J. Charpin, “Effect of Short-Term, Low- level Nitrogen Dioxide Exposure on Bronchial Sensitivity of Asthmatic Patients”, J. Clin. Zn- west., February 1976, 57, (z), 301

35 R. A. Mostardi, D. L. Ely, N. R. Woebkenberg, B. Richardson and M. Jarrett, “The University of Akron Study on Air Pollution and Human Health Effects”, Arch. Envinm. Health, September/October 1981, 243-249, 250-255

36 G. S. Wetstone and A. Rosencranz, “Acid Rain In Europe And North America”, Environmental Law Institute, Washington, D.C., 1983

37 D. Derwent, “A Better Way To Control Pollu- tion”, Nature, 1988, 331, 575

38 International Conference of Ministers on Acid Rain, Ottawa, Canada, March 1985. Organised by the Canadian Government as a Summit Meeting

39 Committee on Motor Vehicle Emissions for the Australian Transport Advisory Council, “Report on the Development of a Long-term Nauonal Motor Vehicle Emissions Strategy”, 1981

40 Environmental Protection Service, “Air Pollution Emissions and Controls Heavy Duty Vehicles”, Ottawa, Ontario, Canada, September 1986

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4 R. L. Madden, “ T d i c Perils Economic Boom of Suburbs Around New York”, New York Times, Monday, 4 July 1988

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47 Naturvardsverket Rapport 3261. Utslapp av uft- fororeninqar fran framlida personsilar

48 OCDE, OECD. Long Term Outlook for the World Automobile Industry, Paris, 1983

49 Registry of Vehicles, Registry of Vehicles Annual Report, 1986, Singapore

50 Saudi Arabian Standards Organisation, A Guide to Saudi Motor Vehicle Standards, January 1985

51 List of Saudi Standards, 198711407 52 Sverker Sjostrom, tekn dr., The Motor Vehicle,

Aircraft and the Environment, Sweden, 1988 53 Strategic Analysis Europe, Overview of the West

European Motor Vehicle Market, July 1988


54 The Australian Bureau of Statistics, “Motor Vehicle Registrations, Australia”, April 1988

5 5 The New Zealand Motor Trade Federation, Motor Industry Year Book, Wellington, 1987

56 Transport Canada, 1988 Fuel Consumption Guide, Guide De Consommation De Carburant 1988, Canada: Ministre des Approvisionnements et Services Canada, 1987

57 R. Rothan, Data On Vehicle Populations and Fuel Consumption, Switzerland, Personal Com- munication, 21 June 1988

58 E. Iversen, Personal Communication, July 1988 59 M. Kroon, Mobile Source Control Strategies in

the Netherlands, Atmospheric Ozone Research and Its Policy Implications, Third U.S.-Dutch International Symposium, 9-13 May 1988

60 Transport Canada, Nitrogen Oxides (NOx): In- formation Package For The Special Committee On Acid Rain, House of Commons, 12 May 1988

61 DG 111, European Commission, Draft Paper On Composition of EC-Petrol Car Market and Parc, and on Kilometrage by Classes of Engine Capaci-

62 S. Gospage, DG 111, European Commission, Diesel Cars In The European Community, 26 April 1985

63 S. Gospage, DG 111, European Commission, The EC Parc Of Vehicles Below 3.5 Tonnes, 1984-2000, 26 April 1985

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ty, January 1985

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69 ADAC, Mobilitat Untersuchungen und Ant- worten des ADAC zu den Fragen, June 1987

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Later”, New York Times, 9 September 1987

The New European Emissions Standards The footnote in the preceding paper by

M. P. Walsh on the implications for climate modification due to vehicle emissions, points out that recent changes in European Economic Community standards will invalidate some of the data and some of the conclusions therein.

The “Luxembourg” agreement of June 1985 set carbon monoxide, hydrocarbon and nitrogen oxides emissions standards for cars with large (over 2 litres capacity) and medium ( I .4 to 2 litres capacity) sized engines. Now the Council Directive (89/458/EEC), published on 18th July 1989, sets mandatory standards for small cars (<1.4 litres capacity) which will come into effect during the year 1992.

Emission levels are monitored during a test cycle, which currently represents a

typical European city driving cycle, and in the new small car standards these are limited to 5 grams and 19 grams per test for hydrocarbons plus nitrogen oxides and carbon monoxide, respectively.

These new small car standards are equivalent to those that have been applied in the United States of America since 1983; and based upon experience gained there, it is expected that three-way catalysts employing platinum metals will be used to meet these new European standards. The result will be to retard the rate at which the activities of man are damaging the global environment. It is expected that during 1 9 9 agreement will be reached within the European Communities to bring in similar, and also mandatory standards, to apply to medium and large cars from 1992.


ABSTRACTS of current literature on the platinum metals and their alloys

PROPERTIES X-Ray Photoelectron Diffraction Study of Platinum Particles Deposited on Rutile Titanium Dioxide

216, (1/2), 209-221 X-ray photoelectron diffraction (XPED) has been used to study Pt deposited by thermal evaporation in vacuum on the (IIO), (100) and (001) surfaces of rutile TiO, single crystals. For the (110) and (100) surfaces, after Pt deposition and annealing, an intense modulation of the photoelectron intensity as a function of the emission angle was observed from the PI overlayer. Analysis of these results showed that most of the Pt clusters grew epitaxially with the (I I I) plane parallel to the substrate surface. Complete structural analysis could not be performed for the (001) orien- tated substrate.

Effects of the Film Thickness on the In- terfacial Reaction of Pt/(l 1 1)Si J.-R. CHEN, L.-D. CHANG and F.-S. YEH, J. Vac. Sci. Technol., 1989, A7, (31, 1345-1349 Transmission electron diffraction and X-ray diffraction have been used 10 study the effect of Pt thin film thickness (50-300A) on silicide formation and microstructure when Pt was deposited onto p-type, ( I I 1)-oriented Si substrates, kept at 450°$. p-Pt, Si was observed in samples with 50 and 2wA thick Pt films, but with different orientations. As-deposited samples with 3wA Pt showed the formation of PtSi epitaxial layer, Pt polycrystalline, and the texture polycrystalline of cr-Pt,Si.

Hydrogen Chloride Adsorption and Coad- sorption with Hydrogen or Water on Platinum (1 1 1)

216, (31, 361-385

K . TAMURA, U . BARD1 and Y. NIHEI, surf. sci., 1989,

F. T. WAGNER and T. E. MOYLAN, surf. sci., 1989,

Aqueous C1- ions accelerate the corrosion of all metals, and CI- chemistry is essential to the preparation of platinum metal catalysts. The adsorption of anhydrous HCI on Pt( I I I ) at goK and its coadsorption with H and H,O have been studied by various analytical techniques in order to determine the interaction of CI- species with metals. The chemistry of HCI adsorption and coadsorption on Pt( I I I ) is dominated by strong Pt-CI interactions. Low coverages of HCI fully dissociate on Pt(1 I I) at goK to form disordered adsorbed H and Cl. Higher exposures produced first a well-ordered 3 x 3 phase and then an increasingly disordered form, again of adsorbed H and CI. Gadsorption of HCI + H , 0 produced adsorbed H,O+.

Thermal Reaction between Pt Thin Films and Si,Ge Alloys Q. 2 . HONG and J. W. MAYER, J . Appl. Phys., 1989, 66, (2), 611-615 Thermal reaction of Pt with amorphous Six&,-, alloys (x=0.25-0.75) was studied at 2w-65ooC. At low temperatures of 2w-4w°C, a uniform reacted layer containing a mixture of Pt,Si and Pt,Ge was produced. The formation of these phases was diffusion controlled with a measured activation energy of 1.2 eV for all the Si,Ge,-, alloys. Reaction continued with the formation of monosilicide and monoger- manide. At high temperatures of 4w-65ooC, phase separation occurred in depth with a surface layer enriched with Si and a bottom layer enriched with Ge. The formation of PtGe, and the crystallisation of unreacted amorphous Six& ,-, were observed.

D, on Pd( l l0) : Surface and Subsurface Phases, Absolute Coverages, and Inter- conversion U. MEMMERT, J.-W. HE, K . GRIFFITHS, W. N. LENNARD, P. R. NORTON, N . V . RICHARDSON, T. E. JACKMAN and

2152-2154 W. N . UNERTL, 3. vac. sci. Technol., 1989, A7, (3),

Adsorption of D, on Pd(I 10) at low temperature produced (2 x I) and ( I x 2) phases in sequence. Ruther- ford backscattering data showed that the (2x I) structure was unreconstructed, while the (I x z) was reconstructed, with an entire monolayer (ML) of Pd atoms displaced laterally from their bulklike locations by 20.01nm. Nuclear reaction analysis data demonstrated that depending on the method of preparation, the (2 x I) phase can be associated with a total coverage of I or I. 5ML, while the (I x 2) phase can be produced with total coverages of I. 5 or 2ML. The additional o.5ML, associated with the high coverage of each phase, was due to subsurface adsorbed species.

Surface Phenomena and Isotope Effects at Low Temperature Palladium Hydride Formation and during Its Decomposition R. Dug, E. NOWICKA and 2. WOLFRAM, surf. sci., 1989, 216, (1/2), 1-13 Adsorption states of H and D, arising in the process of low temperature (78K) Pd hydride (deuteride) formation in thin Pd films were distinguished by simultaneous surface potential and pressure measurements. The precursor state for H (D) incorporation into the bulk was determined, and the diffusion coefficients calculated to be (2-4) x 10- 13cm2 /s for H and (0.7-I.5)X10-13cm’/s for D. Surface potential isotherms were obtained for Pd hydride (deuteride) and showed a significant isotope effect.

Plarinum Metals Rev., 1989, 33, (4), 213-223 213

The Effect of Adsorbed Carbon and Sulphur on Hydrogen Permeation through Palladium

Nucl. Mater., 1989, 162-164, 1065-1070 In experiments performed with upstream H, pressures of -10-~-3ooPa and at 355-630K the permeation rate of H, through Pd, on which C or S is adsorbed, varied by a factor of - 10‘. The H recombination coefficient, K,, derived from permeation data, increased by a factor of - 10’ when the C coverage was reduced from 0 . 3 6 to 0.06 at T = h K . A S coverage decrease from 0 . 1 4 to 0 . 0 6 increased K, (T=625K) by a factor of -4.

Thermal Stability of the C - 0 Bond of Methanol on the Pd( l l1 ) Surface: An Isotopic Mixing Study

SOC., 1989, 111, (9, 3 1 5 5 - 3 1 5 7 The thermal desorption of CO molecules produced from methanol decomposition on Pd( I I I) has been studied by isotopic mixing. Using 1JCH,’60H and I* CH :* OH adsorbate molecules, no isotopic exchange in thermally desorbing CO to produce lJC”O and 1zC160 was observed. Along with studies showing that no H , 0 or CH, desorbs, this observation indicates that C-0 bond scission does not occur in any of the surface species derived from methanol.

Unusual Kinetics of Hydride Formation in Mg-Pd Sandwiches, Studied by Hydrogen Profiling and Quartz Crystal Microbalance Measurements

A. KROZER and B. KASEMO, 3. Less-Common Met.,

Hydrogen uptake by Pd-covered Mg samples of Mg thicknesses of 600-1,3oonm with Pd coating of 7-8nm, was studied at 260-403K and at pressures of 0.03-30 Torr by depth profiling and quartz crystal microbalance measurements. The unusual pressure dependence observed for the H uptake which increased with decreasing pressure, is related to the formation of a hydride in the Mg near the Pd-Mg interface. The uptake was kinetically restricted at - 296K and pressures of 20.01 Torr.

Diffusion of Silicon in PdzSi during Growth C. M. COMRIE and J . M. EGAN, J. vac. sci. Technol.,

Radioactive Si has been used to study the diffusion of Si in Pd, Si during silicide formation. Results show that Si diffuses by a vacancy mechanism during polycrystalline Pd,Si growth, and that Si self- diffusion is relatively small in completely formed Pd,Si but is extremely large during silicide growth. The most likely mechanism of Si diffusion in epitaxial Pd, Si is also a vacancy mechanism. Pd does not dif- fuse through epitaxial Pd, Si during silicide growth.

A. 8. ANTONIAZZI, A. A. HAM2 and P. C. STANGEBY, 3.

X. GUO, L. HANLEY and 1. T. YATES, J . Am. Chem.

1. RYDeN, B. HJ(IRVARSSON, T. ERICSSON, E. KARLSSON,

19899 152, (219 295-309

19893 A7, (3, 1 4 9 2 - 1 4 9 6

Spillover Effects in the Detection of H2 and CH, by Sputtered SnOz Films with Pd and PdO Deposits

Actuators, 1 9 8 9 , 17, (3&4), 355-359 R. HUCK, U . BOTTGER, D. KOHL and G. HEILAND, sens.

Auger spectroscopy has been used to study the deposition of up to 10 monolayers (ML) of Pd on SnO,(IIo) crystal faces in UHV. Initial layer-by- layer growth was followed by cluster formation. 0 from the substrate was transferred to the clusters and metallic Sn was observed. After annealing at >650°C in UHV, SnO, reappeared, indicating a strong metal- support interaction. Sputtered SnO, films with an 8ML Pd deposit showed an open substrate surface besides Pd clusters. Spillover effects are discussed to explain the increase in conductance in air containing H, or CH, of films with Pd and PdO clusters compared to those without Pd clusters.

Solubility of Hydrogen in PdzErS, PdzEr,, PdEr, Pd4Er3, and Pd3Er: Thermodynamics of Pd-Er-H Systems s. RAMAPRABHU and A. WEISS, Ber. Bunsenges. Phys.

The solubility of H in the intermetallic compoudds Pd2Ers, Pd2ErI, PdEr, Pd,Er, and Pd,Er was measured by the pressure reduction method in the range I <P /mbar<~ ,mand 473< T/K< 1 , 1 4 8 . The pacial molar enthalpy of solution at infinite dilution (A%) was found to decrease with increase of Pd content. In Pd,Er, however, (A%) was anomalously high at - 4 5 . 1 kJ/mol, which indicates that the formation of the ordered structure results in an additional increase of exothermicity of H absorption reaction. The increase of exothermicity of H absorption in Pd,Er when compared to PdEr may be attributed to the smaller octahedral interstitial hole size. Pd,ErJ, Pd,Er, and PdEr showed decomposition reactions by which Er hydride and the next intermetallic compound in the Pd-Er phase diagram with less Er content were formed.

A Comparative Study of the Solubility and Thermodynamics of Hydrogen in Pd,-,RE, (RE=Dy, Gd, Sm, and Y; x=O.O5 and 0.08) Solid Solution Alloys

Bunsenges. Phys. Chem., 1989, 93, (6), 686-696 Pressure-composition-temperature absorption isotherms have been determined for the Pd I ,RE, solid solution face centred cubic alloys in the pressure and temperature ranges of 2 < P(H,)/mbar < 1,000 and 473 < T/K < 873 using the manometric method. The partial molar enthalpy of solution of H at infinite dilution (A%) becomes more exothermic with increasing x m due to the lattice expansion and an attractive metal-H interaction. The partial molar exgss entropy of H solution at infinite dilutkn (AS y ) decreases with x ~ . The dependence of A of the “expanded” and “contracted” Pd, -xMx alloys on the size of the octahedral interstitial hole sites occupied by H atoms is discussed.

Chem., 1989, 93, (2), 146-148

S. RAMAPRABHU, N. RAJALAKSHMI and A. WEISS, Ber.

Platinum Metals Rev., 1989, 33, (4) 2 14

The Thermophysical and Thermo- chemical Properties of RuO, from 0 to 1 OOOK

and R. SHAVIV, 3. Phys. Chem. Solids, 1989, 50, (4), 429-434 The heat capacity from 5 to 350K of RuO, has been measured by adiabatic calorimetry. For the ther- mgchemical properties at room temperature Cp (298.15K) = (56.42fo.08)Jrnol-~K-’ and SO(298.15K) = (46.15+o.o5)Jmol-~K-’ have been derived. Enthalpy increments relative to 298.15K have been measured by drop calorimetry from 410 to 757K. The thermodynamic functions, including the formation properties A/tIo(T) and A p ( m , , have been derived for temperatures up to I , m K . Accurate thermodynamic data for RuO, is needed to model chemical processes occurring in nuclear accidents.

E. H. P. CORDFUNKE, R. 1. M. KONINGS, E. F. WESTRUM

CHEMICAL COMPOUNDS A New Tetradentate (N-),S2 Macrocyclic Ligand which is Highly Selec- tive for Platinum(I1) and Palladium(I1) E. KIMURA, Y. KUROGI, s. WADA and M. SHIONOYA, 3. Chem. SOC., Chem. Commun., 1989, (IZ), 781-783 A newly designed tetradentate macrocyclic ligand 10,1o-dimethy1-9, I I-dioxo-I, 5-dithia-8, IS-diazacy- clotetradecane (H,L) in which two amide and two sulphide units act co-operatively showed high selectivity and efficiency for complex formation with Pt(I1) and Pd(I1) over Cu(II), Ni(I1) and Co(I1). Complexation of the ligand in MeOH-H,O (I:I) solution containing 2 equiv. of K,CO, (pH-9) occurred quickly ( - I h) with Pd(0Ac) , and slowly ( - I day) with K,PtCI, with simultaneous deprotonation of the amides to give the products [M”LI0 isolated as yellow (100% yield) and col- ourless needles ( - 9% yield), respectively. The most remarkable feature of this ligand is that it does not form complexes with Cu(II), Ni(I1) or Co(I1) under the same conditions. This clear-cut recognition of Pt(I1) and Pd(I1) against other metal ions has no precedent.

Scanning Tunnelling Microscopy of Rh, and Pt12 Carbonyl Clusters Adsorbed on Graphite

ICHIKAWA, J. Chem. soc., Chem. Commun., 1989,

The images of the metal carbonyl clusters Rh, (CO) and [NEt,I ,IPt,,(CO).I adsorbed on highly oriented pyrolitic graphite (HOW) have been observed in well-ordered structures by scanning tunnelling microscopy. The humps observed in the line- scanning image of “Et,l,[Pt,,(CO),,l were determined to originate from a [Pt (CO) ,, I - cluster. In- formation on size and shape was obtained. Humps observed for Rh, (CO) were in an ordered array and showed the arrangement of adsorbed Rh, clusters.

T. FUJIMOTO, A. NKUOKA, J . NAKAhtURA and M.

( ID, 845-848

ELECTROCHEMISTRY Anodic Oxidation of Propylene Car- bonate on Platinum, Glassy Carbon and Polypyrrole. An “in-situ” FTIR Study P. NOVAK, P. A. CHRISTENSEN, T. IWASITA and w. VIELSTICH, J. Electmanal. Chem. Interfacial Elec- trochem., 1989, 263, (I), 37-48 The electrochemical oxidation of propylene carbonate (PC) was studied on Pt, glassy C and polypyrrole electrodes and production of CO, and other oxidation products was monitored by using in-situ FTIR. At a polished Pt electrode held at +2.0V (vs.Li/Li+), PC was stable but above +2.1V oxidation of PC started and this oxidation greatly accelerated above + 3.5V (vs.Li/Li+). Oxidation of FC was also observed on polypyrrole covered Pt electrodes and on bare glassy- C electrodes, but their decomposition rate was much lower. In Li cells, direct oxidation of PC at high- potential cathodes contributes to self-discharge.

Incipient Hydrous Oxides-The Missing Link in Noble Metal Electrocatalysis

O’LEARY, 3. Electrochem. SOC., 1989, 136, (4), 1015-1021

Charged hydrous oxide species are formed as surface- bound species at adatom sites on Pt at potentials as low as 0.2V (WE) in acid media and, with precautions taken to minimise deactivation problems, many reactive organic compounds commence oxidation in this region. Recent spectroscopic data support the view that Pt(IV) species are present on Pt/Ru alloys at low potentials. The species formed on pure Pt in acid above 0.2V is assumed to be Pt(OH), - -based species; the OH ligands not only accelerate many oxidation processes but inhibit certain reduction processes at the interface.

Oxidative Dimerisation of Methane on Silver-Palladium Alloy Electrode, Con- nected with a Solid Oxide Electrolyte

and A. D. NEUIMIN, Dokl. Akad. Nauk SSSR, 1989,

Studies were performed of oxidative dimerisation of CH, on zo%Pd-Ag electrode in high temperature solid oxide electrolyte of o.9Zr02 +o.IY,O, at atmospheric pressure, at 840°C, in a stream containing xo%CH, at ~ m l / s . In electrolytic regime, 0, was introduced into the reaction zone by passing of the electrolytic current through the cell. Dependences of stationary formation rate of C,H, and C,H,, degree of CH, conversion and selectivity of C,-hydrocarbon formation, on the amount of 0,-stream or the ratio of O,:CH, stream rates during oxidation of CH, in the electrocatalytic and catalytic systems are described. The results showed that this type ofelectrocatalytic dimerisation of CH, on Pd-Ag alloys is more convenient than those performed in other catalytic systems. During C, -hydrocarbons formation an important part is played by various electrolytic stages.

L. D. BURKE, 1. F. HEALY, K. 1. O’DWER and W. A.

V. D. BELYAEV, V. A. SOBYANIN, V. A. ARZHANNIKOV

305, (6), 1389-1392


Organicnnorganic Electrodes (ORINELs) with Continuous Phase Components B. AURIAN-BLAJENI, s. c. HOLLECK and B. H. JACKMAN, 3. Appl. Electrochem., 1989, 19, (3), 331-335 A new class of composite materials for electrodes comprising hydrated Ir oxide and polyaniline is described. The ORINELs (organic-inorganic electrodes) were prepared by electropolymerisation of a monomer in the pores of a disordered matrix which was formed by electrodeposition. The characteristic feature of ORINELs is the connectivity of the components. These electrodes have improved response to electrical perturbations as the distance travelled by the counter ions is reduced. Composites were characterised by impedance spectroscopy and current pulse experiments. The rate characteristics of the ORINEL are different from those of the inorganic layer.

PHOTOCONVERSION Charge Transfer Process at Illuminated SemiconductorlEleetrolyte Junctions Modified by Electrodeposition of Microscopic Metal Grain P. ALLONGUE, E. SOUTEYRAND and L. ALLEMAND, 3. Electrochem. Soc., 1989, 136, (4), 1027-1033 Studies have shown that n-GaAs photoanodes can be very well stabilised in aqueous electrolytes by electrodeposition of microscopic, optically transparent Pt grains of various morphologies. Fh morphology was the key parameter to effectively protect the surface against both chemical etching and photocorro- sion. The mechanism of stabilisation by Pt grains was also studied by considering the surface state distributions, determined by photocapacitance experiments, at both bare and modified interfaces. The photovoltaic properties of the modified electrode are better than those of a bare electrode or of a solid Schottky barrier.

In Situ Formation of Ru(I1) Dinitrogen Complex [Ru"(H-EDTA)N, ]-and Its Reduction to NH, by Visible Light Ir- radiation of Pt or Rh Loaded CdS Par- ticulate System in the Presence of EDTA as a Sacrificial Electron Donor M. M. TAQUI KHAN and N. NAGESWARA RAO, 3. Mol. Catal., 1989, 5 2 , (2), LS-LIO In situ formation of [Ru"(H-EDTA)N, 1 -, where H- EDTA is protonated ethylenediaminetetraacetate by visible light irradiation of IURu"'(H- EDTA)CII.2H2O in the presence of Pt (or Rh)/CdS, through which N, is bubbled, is reported. The co- ordinated N in the Ru(I1) complex was catalytically reduced to NH,. For the Pt/CdS particulate system NH, was formed at 0.04 mol NH, (mol cat.)- I h- I. For Rh/CdS the rate reached 0.032 mol NH , (mol cat .) - I h - I . In the presence of a sacrifkial electron donor, EDTA, the rate increased to 0.076 mol NH, (mol cat.)-' h-l for the Pt/CdS system.

APPARATUS AND TECHNIQUE The Measurement of Instantaneous Local Heat Transfer Coeficients in a Cir- culating Fluidized Bed R. L. wu, c. J. LIM and J . R. GRACE, Can. J . Chem.

A small Pt instantaneous heat transfer probe has been developed and used to measure local instantaneous and time-averaged bed-to-wall heat transfer in a cold model circulating fluidised bed riser at three different heights for sand at a superficial gas velocity of 7mls and for solids circulation fluxes up to -7okglm's. The probe consisted of a thin Pt fdm deposited on Icmz glass protected by a thin plastic fdm. This probe design employs simple digital control to maintain the probe temperature constant, and the instantaneous heat flux from the probe and its temperature were determined relatively easily and accurately.

Analytical Utility of Cylindrical Microelectrodes s. T. SINGLETON, J. J. O'DEA and J. OSTERYOUNG, Anal. Chem., 1989, 61, ( I I ) , 1211-1215

The behaviour and utility of z5pm diameter, 0.5-1.0 cm long Pt microelectrodes sealed in microcapillary pipettes has been studied for the cylindrical geometry. Chronoamperometry and cyclic staircase and square-wave voltammetry were performed on the fern-ferrocyanide couple reversible system, and the observed behaviour was as predicted by theory. Plating and stripping of Ag illustrate the practicality of this electrode.

Electrochemical Determination of Cholinesterase Activity and Indication of Its Inhibitors Using a Thick-Film Metalliz- ed Platinum Electrode R. GRUSS, F. SCHELLER, M. J. SHAO and c. c . LIU, Anal. Len., 1989, 22, (9, 1159-1169 A thick fdm metallised Pt electrode operated in the voltammetric mode has been used to determine the cholinesterase activity in human serum and erythrocytes, which indicates the level of organophosphate intoxication caused by pesticides. Inhibitors of the enzyme can also be quantified by the electrode with cholinesterase either immobilised on the electrode or dissolved in the test medium.

Solid Polymer Electrolyte-Based Elec- trochemical Oxygen Sensor H.-Q. YAN and 1.-T. LU, Sens. Actuarors, 1989,19, (I), 33-40 A new type of solid polymer electrolyte-based solid- state electrochemical 0, sensor with a working electrode consisting of a hydrophobic Teflon-bonded Pt black layer pressed on a piece of Nafion membrane, with a diffusion-controlling capillary in front, has been developed. The sensor showed fast response (95% response time of I-zs), small temperature coefficient (0.3%/OC), and long-term stability.

EW.9 1989, 67, (213 301-307

Plarinum Metals Rev., 1989, 33, (4) 216

Planar Amperometric Enzyme-Based Glucose Microelectrode M. KOUDELKA, S . GERNET and N. F. DE ROOIJ, Sew. AC- tuaton, 1989, 18, (2), 157-165 The fabrication and performance of a small (0.8mm x 3mm) amperometric glucose sensor containing a transducer consisting of a planar 3-electrode cell with Pt working and counter electrodes and AglAgC1 reference, coupled with an immobilised glucose OX- idase membrane, are described. An outer polyurethane membrane renders the sensor response less dependent on dissolved 0 concentration. The potential for development of a cheap, disposable glucose electrode for biomedical applications is shown by the easy, reproducible fabrication of the device, its linear response up to 40mM glucose with sensitivity of I . 8 f o.mA/mM.

Sensing Characteristics and Working Mechanism of Four-Probe Type Solid- State Hydrogen Sensor Using Proton Conductor N. MIURA, T. HARADA and N. YAMAZOE, y. Elec-

A solid-state proton conductor (antimonic acid, AA) H, Sensor composed of a basic electrochemical cell: sample gas, Pt, IAA sheet, Ag, , AA disc, Ag,, AA sheet1 Pt, , AA sheet, sample gas, has been developed. With the two outer Pt electrodes short-circuited the potential difference between the two inner Ag probes was used as a signal output in t h i s four-probe type sensor. Output was proportional to H, concentration (up to 1.3%) in air, and independent of relative humidity (7-90%).

Effect of Platinum Distribution on the Hydrogen Gas Sensor Properties in Tin Oxide Thin Films T. SUZUKI, T. YAMAZAKI, K. TAKAHASHI and T. YOKOI, J. Muter. Sci., 1989, 24, (6), 2127-2131 Tin oxide and Pt layers were deposited on oxidised Si wafers by ion-beam sputtering. Studies at 3moC of the H, sensing properties of undoped films and Pt- doped films showed that surface Pt, when annealed with the SnO, film at 5oo°C, increased the sensitivity and reduced the response time compared to those of undoped films. Longer annealing times tended to increase the optimum sensor thickness.

Graphite Furnace Determination of Molybdenum by Palladium- Hydroxylamine Hydrochloride Matrix Modification E. w. LOYA, At. Specrrosc., 1989, 10, (z) , 61-65 The addition of an equal volume of a solution containing 0.1% Pd and 1.0% hydroxylamine hydrochloride greatly improved the accuracy of results obtained for the determination of Mo in natural waters by graphite furnace atomic absorption spectroscopy. Precision was improved by 47% and sensitivity by 36% by the reduced Pd matrix modifier.

troChO?I. SOC., 1989, 136, (4), 1115-1219

Use of Palladium(I1) Chloride as a Colour-Forming Reagent for the Deter- mination of N-Acetyl-L-Cysteine in Water and Fluimukan Injections T. s. JOVANOVIC and B. s. STANKOVIC, Anal., 1989,

Study of the formation of a complex between WCI, and N-acetyl-L-cysteine (NAC: a biologically active substance used as an antidote for acetaminophen poisoning) in Britton-Robinson buffer solution at pH= 2.08-8.00 has led to the development of a simple, rapid and accurate spectrophotometric method for the determination of NAC in water and in Fluimukan injections in concentrations of 4.0-65.3pg/ml. The detection limit was 1.63pg/ml of NAC. The relative standard deviation varied from 0.63 to 1.92% for NAC in 8.16-32.64pg/ml.

The Ammonia Sensitivity of Pd-Ir Alloy- Gate MOS Field-Effect Transistor 2. WEIXIN and z. LINGJUAN, sem. Actuators, 1989, 19, (21, 177-181 A new NH -sensitive metal-oxide-semiconductor field-effect transition (MOSFET) based on the use of a sputtered Pd-Ir alloy gate has been developed. Comparisons of sensitivity and selectivity of the Pd-Ir gate MOSFETs with data reported for others shows that these devices are highly sensitive and have good selectivity for NH .

Plasma-Edge Diagnostics Based on Pd- MOS Diodes

and D. N. RUZIC, y. Nucl. Mater., 1989, 162-164, 587-592 Palladium metal-oxide-semiconductor (MOS) devices showed rapid, sensitive, dosimetric and reproducible response to energetic H,. W-MOS diodes can be regenerated when saturated with H by heating to 1oo-20o0C for a few minutes. These properties, along with the devices small size, make it useful for plasma-edge diagnosis of H particle fluence when the energy distribution of the incident H is known. Pd- MOS diode sensors were used in the laboratory and in the ZT-qoM reversed-field pinch to measure energetic H fluxes.

Mechanism of Hydrogen Gas-Sensing at Low Temperatures Using Rh/Ti02 Systems c. MUNUERA, A. R. GONZALEZ-ELIPE, A . M U ~ ~ O Z , A. F E R N ~ D E Z , J. SORIA, J . CONESA and J. SANZ, sens. Ac- tuaton, 1989, 18, (3 i% 41, 337-348 The effects of H, adsorption on the conductivity of pressed pellets of a Rh/TiO, polycrystalline material were studied as a function of the degree of hydroxylation and reduction of the TiO, support. The results which were obtained by EPR, NMR and i.r. spectroscopic studies showed that this material can be an efficient sensor for H, at 295K in ambient atmosphere. A behaviour mechanism is proposed.

1x4, 401-403

R. BASTASZ, B. L. GAIN, T. E. CAYTON, R. C. HUGHES


HETEROGENEOUS CATALYSIS Evolution during Thermal Treatment of Pure and Lanthanum-Doped Pt/Al,O, and Pt-RhlAl 0 Automotive Exhaust Catalysts. Transmission Electron Microscopy Studies on Model Samples F. OUDET, A. VEJUX and P. COURTINE, Appl. Catd.,

Lanthanum-doped and undoped Pt/Al,O, and Pt- Rh/Al, 0 , automotive exhaust model catalysts were thermally aged step by step in air up to w 0 C . Systematic transmission electron studies after each step of thermal ageing showed that the La exerted a stabilising effect on the Al,O, support and on the metallic dispersed phase. Results suggested that La does not mod& the mechanism of thermal sintering but limits its extent at high temperature. With Rh- containing undoped samples, severe modifications were observed at low temperature.

Enantioselective Hydrogenation of a- Keto Esters: Temperature-Programmed Reduction Study of Liquid-Phase PtlAl 0 Hydrogenation Catalysts

WEHRLI, Appl. Catal., 1989, 5 2 , (I-& 19-32 The effect of thermally pretreating Pt/Al,O, catalysts in H, on enantioselectivity and activity in the liquid-phase hydrogenation of a-keto esters and the structure and oxidation state of the catalysts was studied by TPR, CO and N adsorption, and X-ray diffraction techniques. Thermal pretreatment in H, at 673K gave 15-20% higher optical yields of cr- hydroxy esters produced and the activity of the catalyst was up to three times higher for the activated catalysts. The TPR studies showed three well resolved peaks which were assigned to a Pt oxide shell on a Pt core at 200-400K, residual Pt salts at 4m-550K and C deposits that originate from the liquid-phase preparation processes at 600-700K. The amount and reducibility of the Pt oxide was determined by TPR and correlated with the activity of the catalysts when strongly oxidised catalysts show lower activities.

I9’Pt NMR Studies of Supported Catalysts 1. P. BUCHER, J. BUTTET, J . J. VAN DER KLINK, M. GRAETZEL, E. NEWSON and T. B. TRUONG, Colloids Surf., 1989, 36, (2) , 155-167 An overview of 19s Pt NMR data for Pt catalysts supported on Al,O,, SiO,, TiO,, and C carriers is presented. The fraction of atoms at the surface of the metal particles (the dispersion) can be derived from the spectra. Effects of surface treatment (oxido- reduction, H absorption, strong metal-support interaction) are discussed in terms of the electronic local densities of states at the Fermi energy level. The qualitative features of the I ” P t NMR spectrum are independent of the carrier material in the series SO, , Al , 0 ,, TiO, , unless a high-temperature reduction is performed.

1989, 5% (I), 79-86

H. U. BLASER, H. P. JALET’T, D. M. MONTI and J . T.

Identification of Dispersed Platinum on y-Alumina by Laser-Raman Spectroscopy K. ono, w . H. WEBER, G. w. GRAHAM and 1. 2. SHYU, Appl. Surf. Sci., 1989, 37, ( z ) , 250-257 Laser-Raman spectroscopy has been used to identify highly dispersed Pt on y-Al,O , . Under conditions favourable for dispersed Pt three peaks were observed at about 125, 335 and, 590 cm-I. Results indicated that dispersed Pt coemsts with particulate Pt even at concentrations as high as 30 wt. O/oPt/y-Al , 0 , . The method can be used to study sintering and redisper- sion of Pt as a function of temperature and gas-phase.

Aromatization of n-Hexane over Pt-KL Catalyst I. MANNINGER, x. L. xu, P. T ~ T ~ N Y I and z. PML, Appl. CUtUl., 1989, 51, (I), L7-L11 Studies have shown that Pt on KL-zeolite promotes aromatisation, isomerisation and hydrogenolysis of n- hexane with a selective pattern similar to Pt/SiO, (EUROPT-I). Studies of the possible routes of aromatisation of n-hexane showed that olefms may be intermediates. The formation of cyclohexane in the aromatisation process at higher H, pressure has been confirmed by a “C radiotracer study.

Study of Genesis of Active Phase of Platinum Catalysts for Complete Oxida- tion Modified by Rare Earths

SEMIKOLENOV, A. L. CHUVILIN and P. G. TSYRUL’NIKOV, Kinet. Katul., 1989, 30, ( 2 ) , 422-428 Studies of the effect of rare earth cations on the character of thermolysis were made during thermodecomposition of H, PtCl -Ln(NO , ) , mixture in air (where Ln is La or Ce), and temperature at the end of the decomposition of the mixture, and phase state of the product were established. The decomposition of the mixture H,PtCI,-La(NO,), proceed- ed with mutual acceleration of thermodecomposition of the components and was accompanied by formation of La oxychloride, with ionic Pt stabilised in its structure. The decomposition of the mixture H,PtC16-Ce(N0,) , resulted in the formation of Ce(1V) oxide and metallic Pt.

ESCA, SIMS, SEM and XRD Investiga- tions of Pt-1O%Rh Catalyst-Gauzes

R. MERTENS, 0. A. KOEIMAN and K. H. BERRESHEIM, Fresenius Z . Anal. Chem., 1989, 333, (4-9, 535-539 The nature and origin of harmful surface contaminants of spent P t - ~ o Y o R h catalyst gauzes used in HNO , acid production has been determined by HR- SEM, ESCA, SIMS and XRD. All used gauzes showed a strong Rh surface enrichment (Rh:Pt-z:~ at.%). The extent of Rh oxidation and the surface structure were determined for head, mid and tail gauze positions. Results showed that the degree of surface contamination could be greatly reduced and optimisation of several process parameters could improve the effective lifetime of the Pt-Rh catalyst.

V. A. DROZDOV, E. I . GRIGOROV, P . E. KOLOSOV, A. S.

A. P. V. ROSENSTIEL, W. H. J. BRUIS, G . H. VAN OS, P.


State of Palladium in Pd/AIZO3 and Pd- Ce/Al,O, Catalysts from i.r.- Spectroscopic Data and Its Effect on Their Activity during CO Oxidation A. L. TARASOV, v. A. SHVETS and v. B. KAZANSKII, Kinet. Katal., 1989, 30, (9, 396-402 The i.r.-spectroscopy of adsorbed CO molecules and high temperature impulsive reoxidation studies were used to determine the effect of Pd and Ce interactions in deposited Pd-Ce/Al,O, catalysts containing 0.5wt.% Pd and up to 2wt.% Ce, on their oxidative- reductive properties. The results showed that Pd promotes Ce reduction and Ce in return inhibits Pd reduction. Addition of Ce to the catalysts also results in a lower share of Pd surface available as crystallographic Pd(1 I I) phase. Thus, under oxidation conditions, Pd/Al,O, and Pd-Ce/Al,O, catalysts were more active during CO oxidation than during reduction.

Temperature-Programmed Deeorption Studies on Pd/Ce02 after Methanol and Formic Acid Adsorption and Carbon Monoxide-Hydrogen Reaction c. DIAGNE, H. IDRISS, I. PEPIN, J. P. HINDERMANN and

Temperature programmed desorption (TPD) studies on 3%Pd/CeO, (and 3%Pd/SiO,) catalysts after methanol and formic acid adsorption and CO-H, reaction suggested that formyl species are involved in CH,OH synthesis on Pd/CeO, catalysts, whereas on G O , formate could be the main intermediate. After adsorption of formic acid on CeO, alone, CH,OH was desorbed with a maximum at 540-550K, indicating the possible hydrogenation of formate species to methanol. However, no CH,OH was observed after formic acid adsorption on 3%Pd/CeO,. Methanol desorption after CO-H, reaction on CeO, produced a TPD peak at 383K, possibly after methoxy hydrogenation, and a peak at 535K, possibly due to hydrogenation of formate. TPD after CO-H, reaction on 3%Pd/CeO, gave results similar to those after CH,OH adsorption.

Effects of Palladium Particle Size and Palladium Silicide Formation on Fourier Transform Infrared Spectra of CO Ad- sorbed on Pd/Si02 Catalysts L.-L. SHEU, z. KARPINSKI and w. M. H. SACHTLER, J. Phys. Chem., 1989, 93, (IZ), 489-4894 The two major modes of CO adsorption on Pd/SiO, , bridging (B) and linear (L), reflect different extents of back-donation which is controlled, in part, by the local electron density at the adsorption site. The formation of B-CO increases with increasing Pd particle size, while that of L-CO decreases, indicating high electron density at Pd atoms in terraces of close- packed crystal faces. A B/L vs. metal dispersion curve was obtained for samples reduced at 3moC and 6ooOC. At 6oo°C significantly lower B/L values were obtained due to Pd silicide formation.

A. KIENNEMANN, Aml. catid., 1989, 50, (I), 43-53

Elementary Steps in the Formation of Highly Dispersed Palladium in Nay. I. Pd Ion Coordination and Migration S. T. HOMEYER and W. M. H. SACHTLER, J. catal., 1989, 1x7, (I) , 91-101 Detailed examination of the processes occurring during calcination of ion-exchanged Pd(NH,), +/Nay have shown that the ammine ligands are oxidised to N, and H,O in discrete steps yielding Pd(NH,), +

and Pd(NH,), + in the zeolite supercages (calcination at <25ooC), and Pd(NH,), + (300°C) and Pd, +

(400OC) in sodalite cages. The relative abundance and location of these ions can be controlled by the calcination programme. The Pd particle size after reduction depends on the location and co-ordination of Pd ions after calcination. A general principle is given in which the relative rates of nucleation and growth determine the particle size in the kinetic regime. Accordingly, highest dispersion of Pd is achieved by retaining the Pd ions in the supercages and maximising the diammine:tetraammine ratio.

Highly Selective Dimerization of Ethylene over Pd-Mg-X Zeolite and Determination of Its Active Sites by In- frared Spectroscopy T. BABA, K. NAKANO, s. NISHIYAMA, s. TSURUYA and hi. MASAI, Appl. catal., 1989, 52, (I-& 81-91 Studies of the dimerisation of ethylene over X-type zeolite containing Pd’ + and an alkaline earth metal cation Mg’ + were performed in order to prevent the decrease in the catalytic activity of Pd-Ca-X. X-type Pd, + and Mg’+ containing zeolite had a high catalytic activity and a high selectivity for the ethylene dimerisation at 305K when it was pretreated with 0, at 6ooK and a constant catalytic activity of X-type zeolite exchanged with Pd’ + was maintained by Mg, + introduction. The i.r. spectroscopic results showed that Pdz + is the catalytically active species and the primary product, I-butene, is formed over Pd’ + sites in the zeolite.

Conversions of Carbon Monoxide on Membrane Catalysts Based on Palladium Alloys. 11. Interaction of CO and H2 on Palladium-Nickel Alloys Covered by Dispersed Layers of Nickel and Copper 0. s. GUR’YANOVA, YU. M. SEROV, s. G. GUL’YANOVA and v. M. GRYAZNOV, Kinet. Katal., 1989, 30, (2) ,

471 -474 Studies of CO hydrogenation on Pd-Ni alloys covered by layers of Ni or Cu were performed at atmospheric pressure and 563-663K. The results showed that in addition to the normal yields of methane, ethanol and ethylene formed from CO and H, on the Pd-Ni alloys, after covering alloys with Ni, propane, propylene and a number of butanes and butenes were formed. On Cu covered surfaces, however, only methane was formed. Various methods of H, introduction into the reaction zone and their effects on activity and selectivity of the catalysts were also studied.


Dissociation and Oxidation of Carbon Monoxide over RUAI 0 Catalysts B. K. CHO and c. J. STOCK,J. caral., 1989, 1x7, (I) , 202-217 Transient isotopic pulse experiments using a packed- bed reactor have shown significant CO dissociation activity during CO oxidation over Rh/AI,O, catalysts. Oxidation of CO proceeds via dissociative oxidation by its own 0 as well as via direct oxidation by gas phase 0, on well dispersed Rh/AI,O,. The rates of CO dissociation and CO oxidation were of the same order of magnitude; under steady state conditions at 30o0C, CO dissociation rate was - 112 that of direct oxidation. CO oxidation performance of Rh/AI,O, was better at low temperatures, possibly due to high CO dissociation activity. NO in the feedstream affected product distribution. The importance of CO dissociation kinetics is discussed, with reference to the different activities between single- crystal Rh surfaces and well-dispersed Rh/Al , 0,.

Selective Hydrogenation of Esters to Alcohols with a Catalyst Prepared from R h 2 0 3 , Sn(n-C4H9)4, and SiO,: Evidence for Site Isolation

A. FERRE’ITI and J . -M. BASSET, Angezu. Chem., hi. Ed. E n d . , 1989, 28, (31, 347-349 The Rh-Sn/SiO, catalyst, which was formed by reac- tionof Sn(n-C,H,), with Rh,O,/SiO,, was more active and selective than Rh/SiO , for the hydrogenation of ethyl acetate to ethanol. The result indicates the ability of Sn atoms to isolate Rh atoms from their neighbours, as shown by the absence of bridged CO ligands after chemisorption of CO on the Rh-Sn/SiO, catalyst and leads to an increase in selectivity in the hydrogenation of ethyl acetate. The amount of ethanol increased from 57.2 for Sn:Rh=o:x to 97.2% for Sn:Rh = I .7: I. At the same time the conversion of ethyl acetate increased from 1.32 to 4.66%.

Shape-Selective Hydrogenation of Olefins with a Rhodium-Zeolite Catalyst T. JOH, I. YAMAGUCHI and s. TAKAHASHI, Nippon Kagaku Kaishi, 1989, (3), 487-492 The shape-selective hydrogenation of olefins over Rh/NaY catalysts was studied on catalysts prepared by drying and calcinating of a Rh ion-exchange zeolite, [Rh(NH,),l’+/NaY (~.gwt.% Rh), followed by treatment with CO at r30°C giving a Rh carbonyl cluster zeolite which was further treated with H, at IZOOC. A pale brownish grey powder of Rh/NaY catalyst thus produced catalysed hydrogenation of various olefins with rates depending on the size/shape of olefin molecules. Selectivity of the catalyst was evaluated on the basis of comparison with Rh/C in the competitive hydrogenation of two kinds of olefins in a single medium. The results obtained showed that the active Rh species were located inside the zeolite cavities. The Rh/NaY catalyst may bt applicable to shape-selective hydrogenation owing to the molecular sieve nature of the zeolite support.

A. EL MANSOUR, J. P. CANDY, J. P. BOURNONVILLE, 0.

Structural Characterisation of Zeolite- Entrapped Rh6 and RhFe Bimetallic Clusters and Their Catalysis in CO Hydrogenation Reaction A. FUKUOKA, L.-F. RAO and M. ICHIKAWA, Nippon Kagaku Kaishi, 1989, (3), 561-568 Studies of Rh, and bimetallic RhFe clusters syn- thesised within NaY zeolite supercages showed Rh,(CO),, entrapped in NaY with i.r. spectrum of terminal carbonyl bands at 2,096 (s), 2,046 (w), and 2,020 (w), and a broad band at 1,760 (m) cm-’ due to the triply bridging CO interacting with Al + or Na+ located on the wall of the NaY supercage. Prechemisorbed S on the reduced Rh, /Nay selectively suppressed the bridging CO chemisorption. Rh K- edge EXAFS studies of Rh,(CO) ,,/Nay provided evidence for the stoichiometric formation of hexa- nuclear Rh carbonyls within NaY supercage. The use of Rh, (CO) /Nay catalyst led to the selective formation of olefin-rich C , - C , hydrocarbons in CO hydrogenation while the bimetallic RhFe/NaY catalysts showed higher selectivity for C, -C, alcohols.

Synthesis of 2-Arylethanols by the Reac- tion of Benzyl Halides with CO/H2 Us%g a Cobalt-Rhodium Bimetallic Catalytic System M. ISHINO and T. DEGUCHI, J . Mol. catal . , 1989, 5 2 ,

(2) , LI7-LI9 A novel reaction catalysed by a Co-Rh bimetallic system, which gives 2-arylethanols from benzyl halides and COiH, is reported. The activities of Rh, Co-Rh and Co, catalysts were determined. Co-Rh gave 2-phenylethanol in good yield in a one-step hydroxymethylation mechanism of benzyl halide. Co gave 2-phenylacetaldehyde almost exclusively and Rh gave 2-phenylethanol as well as the aldehyde. The results suggest that Co and Rh, respectively, catalyse the formylation of the benzyl halide and the reduction of the aldehyde.

A Controlled Atmosphere in Situ X-Ray Diffraction Study of the Activation and Performance of Ammonia Synthesis Catalysts Derived from CeRu ,, CeCo, , and CeFe, A. P. WALKER, T. RAYMENT and R. M. LAMBERT, J . Catal., 1989, 117, (I), 102-120

Highly active NH , synthesis catalysts derived from CeRu,, CeCo, and CeFe, intermetallic alloy precursors have been studied at up to 50 bar and 550°C, with precursor activation in H , , N , /H , and CO/H, . Precursor activation in N,/H, produced active and thermally stable Ce hydride systems which showed NH, activity decreasing in the order CeH,+,/Ru>CeH ,+x/Co>CeH,+,/Fe. CeO, /( Ru, Co, Fe) catalysts produced by activation in CO/H, had a much lower activity for NH, synthesis. The special activity of the hydride based catalysts could be due to intimate interaction between the support phase and the ultradispersed transition metal particles.


HOMOGENEOUS CATALYSIS Water Soluble, Zero-Valent, Platinum-, Palladium-, and Nickel-P(CH,OH) Com- plexes: Catalysts for the Addition of PH, to C H 2 0

PRINGLE and M. B. SMITH, 3. Chem. Soc., Chem. Com- mun., 1989, (16), 1~96-1097 Studies have shown that the air-stable phosphine P(CH, OH) , forms H,O-soluble complexes IM{P(CH,OH),},l where M is Pt, Pd or Ni, which are catalysts for the production of the ligand itself from PH, and C H , O . The Pt complex was readily protonated by H,O, and a reaction scheme is given. The crystal structure of the Pd complex is also described showing that Pd atom is sheathed by the 12 alcohol groups which presents a highly hydrophilic surface to an approaching solvent.

Competitive Routes of Decay of Pt(I1) and Pt(1V) Ethyl Complexes in Aqueous Iodide Solutions. Estimation of Contribu- tion of @-Elimination s. A. MITCHENKO and v . v. ZANASHCHIKOV, Kinet. Katal., 1989, 30, (2), 297-302 Studies in the system NaI(1 .3 -3 .3M)- H C 1 0 , ( o . 1 - 2 . 5 M ) - H 2 0 showed that Pt(I1) (0 .02 -0 .16M) catalysed hydrogenation of ethylene to ethane, and hydrohalogenation of ethylene to ethyliodide, at 353K, upon which the latter product reacted with F't(II), again yielding ethylene or directly being reduced to ethane. A reaction mechanism, which included the intermediate formation of Pt(I1) and Pt(1V) ethyl complexes is given. The basic route of decay of ethyl Pt(1V)-6-eliminated complexes was determined in which the rate was twice the rate of complimentary reduction of C, H , Pt(IV) to C, H , Pt(I1) and reducible elimination yielding C,H,I, when [P~(II)I=o.IM. Ethyl Pt(I1) complexes, in contrast to C,H,Pt(IV), decay in two ways: protolysis forming ethane and reoxidation to

Stereoelectronic Requirements of a Pd(0)-Catalyzed Cyclization. A Synthesis of allo-Pumiliotoxin 339B

K. N . HARRISON, P. A. T. HOYE, A. G. ORPEN, P. G.

Cz H 5 WV).

B. M. TROST and T. S. SCANLAN, 3. Am. Chem. SOC.,

1989, 1113 ( I D , 4988-4990 '

Studies of a synthesis of allo-pumiliotoxin 339B, one of the most complex indolizidines, have established the geometric boundary for endo-type Pd-catalysed cycloalkylations to be between 5 and 6, and suggests an astonishing similarity of a Pd cationic leaving group to a conventional leaving group. With respect to pumiliotoxin, Pd-catalysed alkylations of vinyl epoxides provides a facile entry into the basic in- dolizidine ring system, allows a concise convergent strategy, and controls the creation of the proper stereochemistry at C(II) by chirality transfer. The potential of this sequence as a general route to this in- triguing alkaloid family is suggested.

Hydrocarboxylation of Polybutadiene on Palladium Complex Catalysts A. L. LAPIDUS, S. YA. GROBOVENKO, A. V. GORYACHEV- SKAYA, E. L. BERMAN and A. D. KAGARLITSKII, IZV. Akad. Nauk SSSR, Ser. Khim., 1989, (6), 1 3 9 - 1 3 9 2

Carboxylated polybutadiene was prepared by catalytic carboxylation of CO in the presence of Pdcl,(PPh,), catalyst. The results showed the possibility of introduction in polybutadiene of up to 60% of carboxylic groups in the presence of the Pd catalyst with PPh, addition at 9 0 - 1 7 0 ° C and CO pressure of a.o-xq.oMPa, due to the presence of double-bonds in the polymer.

Excimer Laser-Induced Homogeneous Catalytic Reactions n. MORIYAMA, A. YABE, H. ARAKAWA, T. SAKAKURA and M. TANAKA, Shokubai, 1989, 31, (2), 100-103

Homogeneous hydrogenation of olefins under mild conditions by RhH(CO)(PPh,) , was accelerated by Xecl excimer laser irradiation. Significantly enhanced dark reactions were observed after periods of laser irradiation, which generated highly active catalytic species. The apparent quantum yield was estimated to be > I . However, hydroformylation of ethylene was not accelerated by laser irradiation. It is suggested that photoexcitation processes are involved in the catalytic cycle besides photodissociation of the CO ligand, as in the photocatalysed C-H bond activation of hydrocarbons using RhCl(CO)(PMe 3 ) different wavelength dependences were observed.

Phosphanorbornadienes as Ligands in the Transition Metal-Catalyzed Synthesis of Fine Chemicals D. NEIBECKER and R. ReAU, Angew. Chem., h i . Ed. E n d . , 1989, 58, (41, 500-501 Highly active and selective Rh hydroformylation catalyst prepared from [Rh(CO),CIl and phosphanorbornadienes in situ, were successfully used for hydroformylation of I-hexene, styrene and ethyl acrylate at 25-80OC. The catalysts a;? suitable for the synthesis of aldehydes from a large variety of olefins, especially functionalised olefins, under very mild conditions. The results are promising for the selective production of hydratropaldehyde.

Selective Dimerisation of Vinylketones into 1,5-Diketones Catalysed by RhCl(PMe 3 ) , M. G. VINOGRADOV and G. I. NIKISHIN, Izv. Akad. Nauk SSSR, Ser. Khim., 1989, (9, 1098-1103 Detailed studies of a-0-dimerisation of methylvinylketones catalysed by Rhcl(PMe ,), were performed and the feasibility of the preparatory synthesis of a number of a-methylene substituted I , 5-diketones from vinylketones of various structure was studied. A selective method of synthesis of a- methylene substituted I ,s-diketones by dimerisation of vinylketones was established; aromatic vinylketone was dimerised easier than the aliphatic one.

I. P. KOVALEV, YU. N . KOLMOGOROV, A. V. IGNATEMO,


Catalytic Reduction of Carbon Dioxide to Methane and Other Species via For- mamide Intermediation: Synthesis and Hydrogenation of HC(0)NH2 in the Presence of [Ir(Cl)(CO)(Ph P) I

Mol. Catal., 1989, 52, (2) , LII-L16 Synthesis and hydrogenation of formamide, HC(O)NH,, in the presence of IIr(CI)(CO)(Ph,P),l and NH, as cocatalyst is reported as a process for CH, formation from CO,. The Ir(1) complex catalysed the synthesis of formamide from CO, + H I +NH,. Then neat formamide was catalytically hydrogenated using the Ir(1) complex to give CH, , N-methylformamide and N,N- dimethylformamide, as well as the five products which were produced by a non-catalytic “blank” run (in the absence of the Ir(1) complex). These complex and unexpected results are discussed in detail.

Highly Selective Synthesis of Aldonolac- tones from Protected AIditols by Ruthenium Complex-Catalyzed Dehy- drogenation. A Method of Converting Aldopentoses to Their Stereoisomers

YOSHIKAWA and Y. UCHIDA, Chem. Lett. Jpn., 1989, (4, 563-366 Highly selective H transfer reaction of substituted diols catalysed by RuH,(PPh,), was used during conversion of aldopentoses into their stereoisomers via protected pentitols, and the selective transformations of L-arabinose and L-ribose to protected L- lyxonolactone and D-ribonolactone, respectively, were thus achieved. It is suggested that high selec- tivities will be achievable for the lactonisations of 2,3-disubstituted I ,4-diols when the difference in the steric bulkiness between the two substituents is sufficient.

L. VASKA, S. SCHREINER, R. A. FELTY and J. Y. YU, 3.

M. SABURI, Y . ISHII, N. KAJI, T. AOI, I. SASAKI, S.

FUEL CELLS Dual Modification of Platinum Electrode by Bonding It to Solid Polymer Elec- trolyte (SPE) and by Its Alloy Formation as Methanol Fuel Cell Anode A. ARAMATA, Shokubai, 1989, 31, (2 ) , 52-35 In the development of a highly active anode for a CH , OH fuel cell Pt metal was first bonded to SPE, then Pt-SPE was modified by other metals such as Ru, Sn and Mo. Pronounced activity toward CH,OH electro-oxidation was observed. The alloy formation with other metals further increased the activity of Pt- SPE. The highest activity was obtained for the ternary Pt-Ru-Sn alloy-SPE electrode with current density of 50 mA/cm’ at 0.4 V vs. RHE at 6o°C in IM CH , OH + o.gM H, SO,. Ternary alloy catalysts were more active than binary alloy catalysts. Activity was also affected by the presence of amorphous alloy phases. The proper choice of the second metals for ternary or quaternary Pt alloy is suggested.

A NafionO -Bound Platinized Carbon Electrode for Oxygen Reduction in Solid Polymer Electrolyte Cells

GOODENOUGH, 3. Appl. Electrochem., 1989, 19, (3), 383-386 A full-factorial statistical method has been used to optimise the amount of binder, the compaction load and the compaction time in order to fabricate Nafion- bound C electrodes containing Pt and pyrolysed CO meso-tetramethoxyphenylporphyrin (CoTMPP). The electrodes are used for 0 reduction in solid polymer electrolyte fuel cells, and it has been found that incorporation of Nafion gel with the C substrate facilitates its binding with the Nafion membrane of such a fuel cell. The polarisation behaviour of a Nafion-bound C electrode containing Pt is compared to that containing COTMPP.

Electrochemical Control of the Partial Oxidation of Olefms with Fuel Cell Reac- tion System

Shokubai, 1989, 31, (2) , 48-51

When a positive potential was applied to the (C,H,,H,O, PdIH,PO, IPt,O,) fuel cell system at 366K, the oxidation of propylene to the Wacker type product, acetone, was enhanced dominantly. The r- ally1 oxidation products, acrolein and acrylic acid, were obtained when a negative potential was applied. Addition of H,PdCl, and HCI to the electrolyte enhanced the rate of acetone formation remarkably. The selectivity to the two types of oxidation depended on the relative concentrations of Pdo (active sites of r-ally1 oxidation) and Pd* + (active sites of Wacker oxidation) coexisting at the interface between Pd- electrode and H,PO, electrolyte.

A. K. SHUKLA, P. STEVENS, A. HAMNETT and J . 8.

K. OTSUKA, Y. SHIMIZU, I. YAMANAKA and T. KOMATSU,

ELECTRICAL AND ELECTRONIC ENGINEERING Magneto-Optical Properties in Ultrathin Co/Pd and Co/Pt Multilayer Films Y. OCHIAI, s. HASHIMOTO and K. ASO, Jpn. J . Appl. Phys., 1989, 28, (4), L659-L660 A polar Kerr loop tracer has been used to characterise the magnetic properties of Co/Pt and Co.Pd multilayer films prepared by magnetron-type sputtering. Both multilayer films had perpendicular magnetic anisotropy when the Co layer became < 10 A. The Kerr rotation angle 6k was enhanced at the film thickness t c 5 o o A and the Kerr remanence: saturation ratio became &:6k = I at t < 2mA. In the COPd system, the coercive force was influenced by the sputtering gas pressure. Simultaneous enhancement in 6k and &:Bk i s assumed to originate from the optical and magneto-optical parameters and the perpendicular magnetic anisotropy, respectively. Ultrathin Co/Pd and CoPt multilayer films are suitable for magneto-optical media due to their strong corrosion resistance.


Annealing Effect on Magnetic Characteristics of Pt/MnSb Multilayered Films T. KAWANABE and M. NAOE, 3. Phys. (Paris), 1989,49, (12), 1783-1784 Magnetic properties of PtMnSb multilayered films depend on the annealing temperature and time. Distinct perpendicular anisotropy has been found in the films composed of MnSb layers sohi thick and Pt layers - I3h i thick after annealing at 4 0 0 O C for 2.5h in vacuum. These films have perpendicular anisotropy constant K,, of 4x10~ ergkc.

Pt and PtSi, Schottky Contacts on n- Type o-Sic

APPl. PhYS., 1989, 65, (9, 3526-3530 The electrical and annealing characteristics of novel Schottky barrier rectifying contacts formed by e- beam-deposited Pt on n-type D-SiC have been studied. Short annealing cycles at 350-80o0C led to the formation of a mixed structure of PtSi, and PtC at the Pt/SiC interface, as shown by migration of Pt into the Sic above 35oOC. The barrier height was found to increase from 0.95 to I .35eV with increasing annealing temperature. The rectifying characteristics improved following an initial 350°C anneal and remained relatively stable up to 8w°C.

A Novel Process for High-Performance Schottky Barrier PMOS B.-Y. TSUI and M.-C. CHEN, 3. Electrochem. soc., I 989,

A novel process for high performance rinsed asymmetric Schottky barrier PMOS transistors with a Schottky barrier junction source and a p-n junction drain is described. PtSi is used to form the source Schottky junction. Spacer oxide is not necessary for this process to isolate the poly-Si gate and the source PtSi; thus the source PtSi may directly contact the in- verted channel. The new Schottky barrier PMOS can circumvent the drawbacks of conventional Schottky barrier PMOS.

PtPTilp-In o . 5 3 Ga o . ,, As Low-Resistance Nonalloyed Ohmic Contact Formed by Rapid Thermal Processing

N. A. PAPANICOLAOU, A. CHRISTOU and M. L. GIPE, 3.

136, (51, 1456-1459

A. KATZ, W. C. DAUTREMONT-SMITH, S. N. G. CHU, P. M. THOMAS, L. A. KOSZI, J. W. LEE, V. G. RIGGS, R. L. BROWN, S. G. NAPHOLTZ, J. L. ZILKO and A. LAHAV, Appl. Phys. Lett., 1989, 54, (23), 2306-2308 Very low resistance nonalloyed ohmic contact of PtRi to I . ~ X I O ’ ~ cm-, Zn-doped In,,,,Ga,.,,As were formed by e-beam evaporation of Pt/Ti films on- to the ternary epitaxial layer and subsequently subjected to rapid thermal processing at temperatures over the region 300-60o0C for 30s. These contacts were ohmic as deposited with a specific contact resistance value of 3 . 0 ~ 1 0 - ‘Qcrn,. A very limited interfacial reacted layer (20nm thick) was observed between the Ti and the InGaAs as a result of heating at 450°C for 30s.

System Bi2 -,Pb,Pt, -,Ru,O, -=: A Pyrochlore Series with a Metal-Insulator Transition G. MAYER-VON K ~ T H Y , W. WISCHERT, R. KIEMEL, S. KEMMLER-SACK, R. GROSS and R. P. HUEBENER, 3. Solid State Chem., 1989, 79, (I), 34-45 The pyrochlore compounds Bi, Pt,O, (insulator) and Pb,Ru,O,,, (metallic conductor) form a continuous series of solid solutions Bi, -,PbxPt, -,Ru,O, --Z. In- creasing substitution of Pt by Ru resulted in a gradual insulator-metal transition. Metallic conductivity was found for a substitution level of x 1 I . 5 .

High-Barrier Height Metal-Insulator- Semiconductor Diodes on n-InP Y. S. LEE and W. A. ANDERSON, 3. Appl. Phys., 1989, 65, (101, 4051-4056 Metal-insulator-semiconductor diodes have been made using Pd, Ni and Au contacts on n-InP covered by 40hi chemically grown oxide. Pd devices gave the highest barrier height of o.8eV and the lowest reverse saturation current density. The oxide had a refractive index of 1.4-1.6 and a composition of mainly In,O, + some InPO, near the surface and mixed oxide + InP near the interface. The temperature dependence of the barrier height was determined.

Anodically Electrodeposited Iridium Ox- ide Films (AEIROF) from Alkaline Solu- tions for Electrochromic Display Devices K. YAMANAKA, Jpn. 3. Appl. Phys., 1989, 28, (4), 632-637 Anodically electrodeposited Ir oxide films from alkaline solutions have been studied for application to electrochromic devices. Micro-crystalline (diameter I & films obtained by the electrolysis of aqueous alkaline solutions containing I r a , , o d i c acid and K, CO, showed good electrochromic reversibility. The colouration efficiency of the fims was about 1/3 that of typical evaporated W oxide films, and the response rate measured by the amount of injected charge was about double. The cycle lives of the cells, composed of electrodeposited Ir oxide films, IM H , PO, -NaOH(pH = 3 - 5) , and an activated C cloth, were >8x106 with a 0.6V, IHZ continuous wave.

MEDICAL USES Shape-Selective Targeting of DNA by (Phenanthrenequinone diimine) rhodium(II1) Photocleaving Agents A. M. PYLE, E. C. LONG and J. K. BARTON, 3. Am. Chem. Soc., 1989, 111, (IZ), 4520-4522 Phenanthrenequinone diimine (phi) complexes of F&(III) are described as a family of new, highly efficient, photocleaving reagents which appear to recognise ostensibly B-form DNA sites on the basis of considerations of shape. Rh(phen),phi’ +, where phen is phenanthroline, is useful as a probe of local variations in major groove size. These complexes may find application both in vitro and in vivo.


NEW PATENTS METALS AND ALLOYS Preparation of Uniform Palladium Particles TANAKA KIKINZOKU KOGYO Japanese Appl . 114,409 Pd particles having a narrow particle size distribution are made by adding alkali metal hydroxide to an aqueous solution of iodopalladate, such as K,WI,. By controlling reaction conditions a high yield can be achieved, and agglomeration of particles can be prevented. In an example Pd particles of 5.5 pm average particle size were obtained with a 4.8-6.5 pm particle distribution (70% of the total particles).

Corrosion Resistant Titanium-Base Alloy NIPPON MINING K.K. Japanese Appl . 1121,041 An alloy having excellent corrosion resistance and workability consists of 0.005-2.0wt.% of at least one of Pt, Rh, Ir and Os, 0.05-2.owt.% of at least one of Ni, Co, Mo, Wand V, a controlled content of up to 0.15wt.% 0, up to 0.3wt.% Fe, and balance Ti. The alloy is made by heat treating at 550-750°C, and is used for environments of non-oxidising acids.

ELECTROCHEMISTRY Electrolysis Cell for High Purity Europium Production RHONE-POULENC CHIMIE European Appl . 299,838A An electrolysis cell has an anode of Pt or Ni, especially solid Pt or Ni, and a cathode of solid graphite, with the cathodic and anodic compartments separated by a cationic type ion exchange membrane. The cell is used for electrolytic reduction and separation of Eu, and gives Eu(I1) in high yield and very high purity, which is used particularly in luminescence.

Degradation Resistant Electrolysis Cathode KANEGAFUCHI CHEM. K.K.

Japanese Appl . 631312,990 A degradation resistant cathode has a substrate dispersion-plated with a multicomponent alloy consisting of at least one from each of Ni, Co and Ag (used as the matrix); Al, Zn, Mg and Si; Pt, W, Rh, Ir and Lu; and Ti, Zr, V, La, Ce, Pr and Nd. The cathode is used for electrolysis of aqueous solutions of alkali metal halideshydroxides, and can be used for a long duration with low H, overvoltage.

Platinum Anode for Ozone Generator NIHON MEDICS K.K. Japanese Appl . 1136,784 An ozone generator consists of a Pt electrode or an electrode with a surface of Pt, arranged concentrically with a stainless steel electrode in dilute salt water. A DC voltage is applied using the Pt elecrode as the anode, and 0, is produced at high current efficiency.

ELECTRODEPOSITION AND SURFACE COATINGS Activator Composition for Electroplating Nickel on Ceramic SPRAGUE ELEC. CO. U.S. Patent 4,806,159 A ceramic surface to be electroplated with Ni is sen- sitised with an activator composition containing 0. ~-pv t .% Pd (which may be partially replaced by Pt andlor Ru), at least 85 wt.% Ag, and ~-rowt.% of one or more of Cu, Si, Bi, Zn, and so on. The activator provides strong adherence of Ni at low cost, and the method is used for example to produce a ceramic chip carrying a thin film resistor.

Chromium Electroplating Apparatus TOPPAN PRINTING K.K. Japanese Appl . 631293,197 Apparatus for Cr electroplating has Pt coated Ti and lead peroxide coated Ti anodic electrode plates hung on separate bus bars. The content of trivalent Cr in the solution is controlled by regulating the surface area ratio of these two anode plates, which gives improved quality of the deposited film, increased service life of the solution, and avoids solution contamination.

Precious Metal Plating Titanium Base Material VICTORIA K.K. Japanese Appl . 631310,993 Ti base material is plated with precious metal by first treating with a solution containing fluoride(s); then subjecting to Ru-strike plating using a bath of Ru sulphate, sulphamic acid and H,SO,; and finally plating with precious metals, for example a Au-Pd plating. Corrosion resistant ornamental materials are obtained by thinner plating.

Optical Fibre Coating Composition TORAY SILICONE K.K. Japanese Appls. 64169-70 A fibre coating composition consists of an organopolysiloxane or a methylphenyl polysiloxane, an organohydrogen polysiloxane, and Pt compounds containing 0.5-1,oooppm Pt metal. The composition hardens rapidly, has excellent air foam breaking property, hardly produces H, gas which can cause a transmission loss, and is used for coating quartz optical fibres for public information and long distance communication.

Catalyst for Electroless Plating HiTAcHI CHEMICAL K.K. Japanese Appl . 64275 Articles for electroless plating are first dipped into a solution of a catalyst containing a complex system having monovalent, divalent or trivalent metal ions, Pd, an alkylamine and a halogen. The method gives improved Pd adsorption properties and Cu covering power, and is used for forming circuitry on the surface of an insulating material.

Platinum Metals R e v . , 1989, 33, (4), 224-231 224

APPARATUS AND TECHNIQUE

High Accuracy Enzyme Sensor TERUMO CORP. World Appl. 891691A An enzymic sensor consists of an enzyme-sensitive unit having an insulating base layer, a conductive Ir oxide layer, and a top layer in which an enzyme is immobilised; a reference electrode unit which is similar but does not contain the enzyme; and a low- impedance load connecting the two units. The enzyme sensor has simple construction, small size, high accuracy, and is especially suitable as a urease sensor.

Biosensor with Receptor Membranes COMMONWEALTH SCIENT. ORG.

World Appl. 8911, I 59A A biosensor is claimed which consists of a membrane bilayer attached to a solid surface, which is preferably a Pd-coated glass electrode. Each layer of the bilayer is composed of self-assembling amphiphilic molecules having ion channels andlor receptor molecules. The membranes have a high density of receptor sites, and serve as highly selective binding surfaces to which molecular species to be detected will bind.

Superior Poly-yne Polymer Non-Linear Optical Material

A protective device has at least one layer of a polymerised transition metal poly-yne containing Pt, Pd or Ni or 2 of these, interposed in the path of laser light to have a non-linear optical effect on the light. The devices are used for optical switching, frequency conversion and protection of sensory organs or sensors, and can protect both instruments and their operators from high energy laser beams.

Enhanced Spectroscopic Metal Deter- mination Using Palladium Modifier VARIAN ASSOCIATES U.S. Patenr 4,806,489 Determination of metals such as As, Se, P and Bi by atomic absorption spectroscopy is enhanced by a non- contaminating modifier comprising Pd plus a surfac- tant. This is added to samples which are heated in a graphite furnace to at least 300OC to reduce the Pd to a finely divided state dispersed in the metals. The modifier increases the vapourisation temperature of the metals, and atomisation peaks obtained during analysis are sharper and more gaussian.

Platinum Electrodes for Ceramic Seneor MURATA MFG. CO. Japanese Appl. 631194,303 A porous Pt electrode of 7.00 mm diameter is provided on each face of a sintered disk consisting of a humidity sensitive ceramic having WO, , MOO, or TeO, added to a major component such as Ca-Zr-La oxide. The humidity sensitive ceramic has high reliability, and is used for ceramic sensors in microwave ranges, ovens or dishwashers. The sensor has good response, and detects absolute temperature even in the high temperature region.

MARTIN MARIElTA CORP. world Appl. 8911,182A

Anisotropic Unwoven Fabric for Sensitive Sensor AGENCY OF INLI. SCI. TECH.

Japanese Appl. 631295,762 An unwoven fabric is manufactured by first adsorb- ing Pd using Pd organosol, and then electroless plating the nylon or vinylon unwoven fabric with Ni, Cu, Co or Ag in an alkaline electroless plating bath. The unwoven fabric is anisotropic and is used for the switch or keyboard of electronic equipment, sensitive sensors, and as a connector of an electrocircuit.

Platinum Micro-Electrode Preparation SHIMADZU SEISAKUSHO K.K.

Japanese Appl. 631300,954 A Pt micro-electrode useful for an enzyme sensor or electrode is prepared by etching part of the suface of a glass base plate by photolithography, and plating Pt on the surface of the plate by sputtering or a non- electrolytic plating method. The Pt electrode can be formed on the glass base plate without an intermediate layer, and can work stably in aqueous solution for long periods.

Production of Fine Platinum Particles TANAKA KIKINZOKU KOGYO

Japanese Appl. 631307,209 Production of fine Pt particles from a chloroplrtinic acid solution involves reducing with a reducing gas at room temperature and pressure, at a specified Pt density of less than 20 gA (less than 0.1 mol), and a specified pH of higher than 7.0. The process precipitates fine Pt particles without causing cohesion (aggregation), and gives particles with narrow grain size distribution.

Stable Gas Sensor for Combustion Control WDENSEI MUKIKAGOBU

Japanese Appls. 631311,160-61 A gas sensor has a base material consisting of an 0 ion conductive solid electrolyte, with an anode having Pt as a main body, and a perosvskite type composite oxide cathode on the other face of the base material. On the cathode is a gas diffusion layer which may consist of, or contain, MgO. The gas sensor is used to detect the &fuel ratio from the dissolved 0, concentration in combustion exhaust gas, and is used for combustion control. The sensor is stable, and measures 0, concentration with good accuracy, for a long period.

Gas Separation Membrane with Two Palladium Layers AGENCY OF IND. SCI. TECH. Japanese Appl. 114,216 A gas separation membrane consists of a porous ceramics layer of pore size less than I pm diameter, with a 1-3 pm thick non-electrolytic Pd metallising layer on the surface, and a 10-30 pm thick electrolytic Pd (alloy) metallising layer formed on top. The gas separation membrane can have a thickness of less than 100 pm, and is useful for selective separation of H, gas.


Combustion Control Sensor with Improved Stability DODENSEI MUKIKAGAKU Japanese Appl. 1/28,549 A sensor component consists of a perovskite composite oxide with a MgO coating layer on the surface, and includes as the sensor material 0-80 mol% of the oxide SrMO, , where M is at least one of Ti, Zr and Hf, with at least one Pt element also included in the sensor material. The sensor component is used in a sensor for controlling combustion, which has improved stability and operates with high accuracy.

Enzyme Sensor with Electrolytically Polymerised Enzyme Layer TERUMO CORP. Japanese Appl. 1/32,160 An enzyme sensor consists of an insulating base, an electroconductive layer of Ir oxide, Pd oxide or Ru oxide, and a fured layer of enzyme formed by electrolytic polymerisation. This process prevents the enzyme from leaking, and the sensor is used for precise measurement of the concentration of a substrate.

Biosensor with Platinum Group Metal Counter Electrode DAIKIN IND. LTD. German Appl. 3,822,886 A biosensor has a basis electrode consisting of a working electrode, a reference electrode, and a counter electrode made of a platinum group metal. An enzyme foil is fured by a material such as glucose oxidase, and is covered by a dispersion control film of cellophane. A bias potential can be applied between the electrodes, so that the biosensor produces an accurate density reading.

JOINING Novel Nickel-Palladium Alloy Used as a Brazing Foil ALLIED-SIGNAL INC. U.S. Parent 4,802,933 A novel Ni-Pd alloy consisting of 38-55at.% Pd, 19-34.5at.% Fe, 11-2oat.Oh Si, balance Ni and im- purities is used in a homogeneous, ductile brazing foil. The alloy has high temperature melting characteristics, and is used as a filer for high temperature brazing of various materials.

HETEROGENEOUS CATALYSIS Palladium Alloy Catalyst for Hydrogen Oxidation in Safety Devices JULICH KERNFORSCHUNGS European Appl. 301,536A A Pd alloy used as a H, oxidation catalyst has at least 8owt.% Pd, up to 19.9wt.% of a Group VIII metal (especially Ni), and a maximum of Iowt.O/o Cu. It is useful in an automatic safety device for eliminating H, and preventing explosive H,/O, gas mixtures forming during nuclear reactor accidents, especially in light water reactors. The alloy provides very high activity and is not sensitive to poisons.

Oxidation Catalysts Containing a p-Type Oxide ENGLEHARD CORP. European Appl. 304,095A Catalysts having a Pt group element, preferably Rh with initial particle size 3-8 nm, 5-30wt.Yo Ce oxide, and AI,O, dispersed on a substrate, are improved by using a p-type oxide dispersed on the support, most of which is in contact with the G O , . The catalytic promoting effect of the G O , is enhanced by the p-type oxide, and the catalysts are used for oxidation of hydrocarbons and CO in engine exhaust gases.

Carbon Monoxide Oxidation Catalysts PHILLIPS PETROLEUM CO.

European Appls. 306,944-45A and U.S Patent 4,808,394

Catalysts consisting of Pt and/or Pd (oxide) and optionally Fe, or Ru, Cu, Re or Fe oxides on an Al , 0 , , TiO, or MgO support are activated by heating in reducing gas atmosphere. The catalysts are contacted with CO plus 0, gas mixtures to oxidise CO to CO,, and are used at o-ioo0C and 5-20 psia (or 1-2,000 psia). Uses include in breathing masks to remove CO from inhaled air, in CO, lasers to combine CO and 0, formed by CO, dissociation during discharge.

Two-Stage Catalytic Conversion of Waste Gas DEGUSSA A.G. European Appl. 308,789A Waste gases containing hydrocarbons, halogenated hydrocarbons and CO, especially from vinyl chloride manufacture are passed through a first zone at 300-800°C with a catalyst for oxidative cracking, and then through a second zone with a Pt, Pd, Pt/Pd or Pt/Rh catalyst for oxidative afterburning having a Pt:Pd wt. ratio of 1:s to 5:1 or a l't:Rh wt. ratio of 5-20:1. Use of the first zone prevents sintering and poisoning of the second zone catalyst.

Catalysts for Carbon Dioxide Regeneration in Lasers HUGHES AIRCRAFT c o . World Appl. 88/1o,151A New catalysts with longer life and lower activation energy for regenerating CO, in lasers consist of l't, Pd, Rh or Ir metal supported on Al 0, or SnO, having at least z types of surface atomic sites, with the metal atoms only at one of the sites. The catalyst is particularly 0.25-1at.% Pt supported on AIIO, in pellet form, and promotes increased reaction throughput, with reduced usage of expensive catalysts at low temperatures.

Palladium-Zinc Hydrogenation Catalysts EASTMAN KODAK CO. World Appl. 89/886A Novel, high activity catalysts consisting of I'd and Zn on a support are readily prepared by a process with several optional steps, and require no special handl- ing precautions. The catalysts are used to promote low pressure hydrogenation of a wide range of car- bony1 compounds, for example alkyl carboxylates, to the corresponding alcohols.


Oxy-Iodination of an Aromatic Compound EASTMAN KODAK CO. World Appl. 891986A The iodination process involves (a) producing molecular I, by combusting a I - I ~ C alkyl or 6-2oC aromatic iodide at 200-1o0o0C in the presence of a source of 0, and an ignition source, which may be at Pt, Pd, Rh, Ru andlor Fe catalyst, and (b) reacting the I , with an aromatic compound. The iodinated aromatic compounds produced can be converted to aromatic carboxylic esters, which are valuable intermediates.

Low Pour Point Lubricating Oil Production CHEVRON RESEARCH CO. World Appl. 8911,506A A lubricating oil is prepared by hydrocracking a hydrocarbon feed to obtain a hydrocracked oil, then catalytically dewaxing at 200-475OC and 15-3,m psig with a catalyst containing a crystalline silicoaluminophosphate, and Pt or Pd, for example o.o~-xowt.% Pt. Less H, is used for dewaxing than with known catalysts, and the lubes have relatively low pour point and excellent viscosity.

New Palladium and/or Rhodium Hydrogenation Catalyst GAF CORP. U.S. Patent 4,795,733 A new hydrogenation catalyst consists of 0.05-5 wt.% Pd andlor Rh, 0.03-10 wt.% Re, and 10-9 wt.% Ni on an Al,O,-containing support which is in fluted extended form. The catalyst can be used for hydrogenation of alkynediols to alkanediols, olefins to alkanes, or particularly 1,q-butynediol to 1,4-butenediol and 1,4-butanediol with higher activity and selectivity. Glycols such as ~,q-butanediol are used as monomers and in the pharmaceutical industry.

Palladium Catalyst for Hydrogen Peroxide Production DU PONT DE NEMOURS CO. U.S. Patent, 4,800,075 A cyclic fued-bed process for H,O, production involves hydrogenation of a solution of quinones using a Pd catalyst on a support containing 5-99% a- Al,O, with a BET surface area of 108-5 m’lg. a- Al , 0 supported catalysts retain their metal composition, have low absorption of acidic products, retain activity and selectivity over commercial times and are resistant to deactivation by H,O,.

Hydrocarbon Conversion Catalyst AMOCO CORP. U.S. Patent 4,808,763 Converting a gaseous feed containing 2-5C paraffinic hydrocarbons to aromatic hydrocarbons uses a catalyst consisting of a gallosilicate molecular sieve, o.ox-Iowt.Oh of a Pt metal component, and 0.1-xowt.% of a C1 component. Activity is stable, and the process is used especially for C,H,, giving greater selectivity towards benzene, toluene and xylene and lower selectivity towards I -2C production than the prior art process.

Combustion Device with Dual Catalysts TANAKA KIKINZOKU KOGYO

Japanese Appl. 63/294,41 I A combustion device for burning a mixture of hydrocarbon fuel and air has a front catalyst of Pd dispersed on a stabilised oxide coated carrier, and a rear catalyst of Pt-Rh alloy, also dispersed on a stabilised oxide coated carrier. Catalyst life can be improved as fuel ignition is easily performed on the Pd catalyst which is not subjected to high temperatures, and fuel burning occurs at the rear catalyst where Pt is included as an alloy to improve its antioxidising property.

Monolithic Catalyst for Cleaning Exhaust Gas NISSAN MOTOR K.K. Japanese Appl. 631302,950 A catalyst for cleaning combustion engine exhaust gas has a monolithic carrier, a coating layer of a perovskite-type compound oxide containing one or more of Pt, Pd, Rh, Ir and Ru; activated Al,O,, and powder of rare earth metal oxide, and one or more of Pt, Pd, Rh and their oxides as the active component. The rare earth metal oxide prevents dissociation of the noble metal oxide, and so suppresses sintering and improves durability.

Filter for Diesel Exhaust Purification TOYOTA JIWSHA K.K. Japanese Appl. 631310,615 A filter consists of 0.5-20 gfl of Pt, Pd or Rh supported on a particle-trapping surface of porous ceramics, with a 0.3-10 pm Cu layer on the noble metal, and a thin Ag layer on the Cu layer. The filter is used for purifying waste gas from an internal combustion engine, especially a diesel engine. The noble metal protects Cu and Ag from heat-degradation, and the Cu maintains good properties.

Catalytic Carbon Monoxide Remover for Gas Masks TOPY KOCYO K.K. Japanese Appl. 631310,627 A CO remover consists of a CO oxidation catalyst havingo.01-0.5 mmollgofaPdsalt,o.1-2.ommollg of a Cu salt and optionally a promoter on a porous support; and a gas adsorbent which has a porous support carrying at least one salt of Ti, V, Cr, Mn, and so on. The remover is used in a gas mask or as a cigarette filter, and effectively removes CO in waste gas containing organic gas, with high activity.

Platinum Catalyst for NO, Removal MITSUBISHI HEAVY IND. K.K.

Japanese Appl. 631319,049 A catalyst for removing NO, consists of anatase type TiO, with at least two of Pt, MnO,, and V,O, at up to I, 10 and 5 wt.%, respectively. The catalyst is used to remove NO, from exhaust gas from coal or heavy oil combustion apparatus at comparatively low temperature, by reduction of the NO, in the presence of NH,. It is used in the combined desulphurisation and NO, removing process.


Ruthenium Reforming Catalyst for Town Gas Production JGC CORP. Japanese Appl. I 19,801 Town gas is produced using a combined apparatus for (a) adiabatic type low temperature reforming at 300-500~C with liquefied petroleum gases or naphtha and a Ru catalyst which is easily changed, and (b) medium temperature reforming at 550-65o0C with the product from (a) and a Ni catalyst. The equipment is simple, its operation is economical, and it is suitable for producing town gas of calorific value 4,000-5,500 kcal/Nm3.

Carbon Monoxide Oxidation Catalyst for Gas Masks

A CO oxidation catalyst is prepared by oxidising an alloy containing Au, Zr, and optionally Pt, Pd, Rh, Ir, Ru, Ag, Si, W or others, in an H,O-containing gas stream at - 100 to 400OC. The waste gas containing CO is treated at - 1 x 1 to goo°C under a pressure of 0-200 atm. The catalyst can oxidise CO even at below normal temperatures, and is used for air cleaners, gas masks or fdters.

Three-Way Catalyst with Palladium and Rhodium in Separate Layers TOYOTA CENT. RES. & DEV. Japanese Appl. 1111,643 A three-way catalyst for removing CO, hydrocarbons and NO, from combustion exhaust has a first oxide layer of Ce and Zr on a monolithic support, a fmt Al,O, layer loaded with Pd, a second oxide layer of Ce and Zr, and either a second Al,03 or ZrO, layer loaded with Rh. The Pd and Rh are on separate layers so that NO, can be removed efficiently even above h 0 C , and low cost Pd is used in place of Pt.

Exhaust Purification Catalyst without Hydrogen Sulphide Generation TOYOTA JIDOSHA K.K. Japanese Appl. 1115,138 A catalyst for purification of car exhaust gas without generation of H,S has at least one of Pt, Pd or Rh supported by A, Ce, Co, with one of Ni, Fe or La. The catalyst components are immersed into the support, then dried and sintered above 5oo°C. Ni, Co or Fe reversibly change from a divalent to a trivalent ion, and the sulphate ion is not converted to H,S.

Preparation of Neutral Palladium Catalysts

IDEMITSU KOSAN K . K . Japanese Appl. 1111,642

TANAKA KIKINZOKU KOGYO Japanese Appb. 1118,443-45

Neutral Pd catalysts for hydrogenation are prepared by impregnating supports of Al,O,, SiO, or active C with a solution of (a) a diaquodiamino Pd salt, (b) a dinitrodiamino Pd salt, or (c) a dichlorodiamino Pd salt, followed by reduction. Strong acids such as HCI do not remain, and the resulting Pd catalysts are neutral, providing an aqueous suspension of pH 6.5-7.5, so they hardly decompose organic compounds on hydrogenation or other organic reactions.

Durable Three-Way Catalyst for Exhaust Gas Decontamination NIPPON SHOKUBAI KAGAKU Japanese Appl. 1/27,643

A three-way catalyst has a honeycomb support loaded with a catalytic composition of average particle size 0.5-20pm, which consists of 5-3owt.% Pt supported on a fire-resistant inorganic oxide, and/or 1-20 wt.% Rh supported on a fire-resistant inorganic oxide, and Ce oxide. The catalyst simultaneously removes toxic components such as hydrocarbons, CO and NO, from exhaust gas, and is durable when used under severe conditions such as a high temperature oxidising atmosphere.

Nitrogen Oxide Decomposition Catalysts

Japanese Appls. 1130,641 and 1130,647-49 Catalyst powders with good thermal resistance consist of 0-I% of a platinum group metal such as Pt, Pd, supported by composite oxide(s) or a perovskite composite oxide containing alkaline earth, rare earth and copper group metals (Cu, Ag), in turn supported by pelletised or honeycomb Al , 0 , , SiO, or cordierite. The catalysts are used at 3 0 0 O C to decompose NO, to N, in exhaust gas from cars or furnaces containing 0, (about 10%) without using a reducing reagent.

Catalyst Layer for Heat Exchanger Wall H. KRAUCH German Appl. 3,723,603

A heat exchanger wall is coated with a catalyst layer containing Pt (oxide), Ag-Cu, Fe(II1) oxide or V (oxide), which is where catalytic chemical fuel conversion occurs simultaneously with flames burning in the combustion zone. The heat exchanger is used for machines in which combustion heat is transferred through a solid wall, such as external combustion heat engines, heat pumps, and so on. The catalyst layer gives improved efficiency.

Improved Exhaust Treatment Catalyst with Metal Carrier MAZDA MOTOR CORP. German Appl. 3,826,155

A catalyst having higher activity for treating I.C. engine exhaust gases is prepared by alternately ar- ranging corrugated and flat metal sheets to form a honeycomb carrier, forming a base layer and top layer of Al, 0 , , and impregnating at least the top layer with catalytically active components, especially Pt and Rh. The catalyst components are uniformly distributed.

Palladium Catalyst System for Selective Hydrogenation VEB. OTTO GROTEWOHL East German Paten1 261,105

At least 2 different particulate Pd/Al I 0, catalysts are arranged in layers or beds, and contain 0.1-2.5 wt.% Pd, Si andlor alkaline earth compounds, alkali compounds, promoters, and Al,O,, having defrned surface and pore characteristics. The catalyst system is used at 273-670 K for selective trickle phase hydrogenation of strongly unsaturated components in hydrocarbon mixtures which boil at 220-500 K.

MATSUSHITA ELEC. IND. K.K.


Highly Selective Palladium Hydrogenation Catalyst VEB. o m GROTEWOHL East German Patent 261,171 Fixed bed PdlAI,O, catalysts are used for selective hydrogenation of strongly unsaturated compounds in the presence of akenes and aromatics, to stabilise gasoline hydrocarbon mixtures. Reaction is under controlled flow, at 280-670 K and up to 7 MPa, using a catalyst of o.~-zwt.% Pd and up to I% alkali metal compounds on an AI,O, carrier with up to 10% SO,, having defmed specific surface, pore data and surface acidity.

Platinum-Chromium-Cobalt Alloy Catalysts for Fuel Cells TANAKA KIKINZOKU KOGYO

Japanese Appls. 631319,051-52 Pt-Cr-Co ternary alloy catalysts are prepared by con- tacting a C black support loaded with Pt powder with a solution of either (a) Cr and Co nitrates, or (b) Co chromate, to adhere 0 and Co to the support. The catalyst is then treated at 800-1,000°C for 0.5-zh in inert gas to form the Pt-Cr-Co alloy. Cr and Co can be uniformly and simultaneously deposited, to give a catalyst which is used for fuel cells.

Cleaning Process for Industrial Exhaust Gases CHEMICAL TECHNOLOGY 0. A. ZUN Russian Patent 1,412,797 Industrial exhaust gases are cleaned by a process consisting of catalytic oxidation at high temperature on two catalyst beds. The second bed has a PtlAI,O, catalyst, while to increase performance the first bed is metal designed for Fe melting, and vapour of the gum materials being removed is also introduced with C dust. This simplified process reduces costs.

Platinum Meshes for Ammonia Oxidation A. V. SHISHKIN Russian Patent 1,416,169 A contact apparatus for catalytic oxidation of NH , to oxides of N2 at 9-950°C has Pt catalyst meshes beneath an ignitable burner made as a tubular ring with holes at the top, which is used to establish and maintain combustion of NH, in 0,. The equipment is used for processing gaseous reagents, such as during production of hydroxylamine-sulphate.

HOMOGENEOUS CATALYSIS Rhodium Catalyst for Olefm Hydroformylation KURARAY K.K. Japanese Appl. 1126,530

Palladium-Copper Alloys for High Purity Hydrogen Production ISE KAGAKU KOGYO K.K.

Japanese Appls. 631294,925 and 63/295,402 Pd-Cu alloys are used for H, permselective membranes (71-94wt.Yo Pd and 6-29wt.Oh Cu) and H, separating fdms (80-92wt.% Pd and 8-zowt.% Cu). The membranes and fdms are made by chemically plating a thin fdm of Pd on the surface of heat resistant porous materials, followed by chemically plating Cu on the Pd f h and heat treating. The membranes and fdms are used for production of H, gas with improved purity and product yield.

Platinum Paste for Heating Elements on Glass Substrates NIPPON DENSO K.K. Japanese Appl. 631314,789 A Pt paste consists of 70-80 wt.% granular Pt, 5-10 wt.% of Au andlor Ag for bonding the Pt mutually, and 3-10 wt.%, glass frit andlor ceramic frit for bonding the Pt to the substrate. The Pt paste is printed and baked on a glass substrate to form a heating element having long term stability at elevated temperature.

Hydroformylation of olefms involves treating with Spinning Nozzle for Chemical Fibre synthesis gas in the presence of Rh compounds and Manufacture tris(substituted aryl) phosphites having characterised AsAHI IND. K.K. Japanese Appl, 116,1 electronic and steric parameters. The Rh catalyst can be supported metallic Rh, Rh oxide, c-boxylic acid The extruding face Of a has at least fi salts, and so on, and is used more economically by one covering layer of pt metals, pt metal oxides, or using the phosphite component. alloys containing the Pt metals. The covering layer is

0 . 5 - 5 p thick at the extruding face and o.I-zgm

FUEL CELLS Platinum-Gallium-Chromium Fuel Cell Catalyst

A ternary metal catalyst consists of at least 5oat.% Pt, 5-2oat.% Ga, and one of 0 , Co, Ni or a &reure onn a carbonaceous support, and has at least 30 m* /g of catalytically active surface. The catalyst has high activity for electrochemical reduction of 0, , and is used in fuel cells where it is resistant to sintering and chemical dissolution and prolongs cell operating life.

UNITED TECHNOLOGIES CORP. U.S. Patent 4,806,515

thick at the extruding groove. The spinning nozzle is used to make a chemical fibre by wet spinning.

GLASS TECHNOLOGY Glass Melting and Tapping System TOSHIBA GLASS K.K. Japanese Appl. 115,917 Class is made by heating and melting glass raw material formulations in a melting bath, and using a run-off hole made of Pt-Au alloy to supply the melt. This system prevents the glass sticking at the run-off holes and stabilises the discharge of the glass, giving homogenous glass free from crystals.


ASAHI CHEMICAL IND. K.K. Japanese Appl. 1/6,110

The extruding face of a spinning nozzle has at least one covering layer of Pt metals, Pt metal oxides, or alloys containing the Pt metals. The covering layer is o.s-spm thick at the extruding face and 0.1-2pm thick at the extruding groove. The spinning nozzle is used to make a chemical fibre by wet spinning.

ELECTRICAL AND ELECTRONIC Long Life Cathode for Microwave Devices

U.S. Patent Appls. 7,200,219 and 7,213,035 U.S. SEC. OF THE ARMY ENGINEERING

Production of Langmuir-Blodgett Films THORN EM1 P.L.C. European Appl. 301,725A Organometallic compounds of Ru, Re or Co are used in the production of Langmuir-Blodgett films having second order molecular hyperpolarisability, chemical stability, and a melting point above 7oOC. The films may be deposited on many substrates, show second order optical non-linear properties, and are used in electronic devices, semiconductors, and sensor and piezoelectric devices.

Magneto-Optical Recording Medium HITACHI K.K. European Appl. 302,393A A recording medium has a substrate with an alloy film having 2-1oat.~/0 of at last one of Pt, Pd, Rh and Au, I-Ioat.% of at least one of Nb, Ti, Ta, Cr and Al, at least one rare earth element, and one Fe group element, with molar ratio of fmt:second metal of 2:1 to 4:3. The alloy has perpendicular magnetic anisotropy, and the medium has high corrosion resistance, as well as high magneto-optical properties and reliability.

Perpendicular Magnetic Recording Medium SOW CORP. European Appl. 304,927A A perpendicular magnetic recording medium is formed by cqating a substrate with a magnetic layer 50-800 A thick, which is a multi-layered film of alternate Co-Pt or Co-Pd layers. An under-layer, 200-2,ooo A thick, of Pt, Pd, Rh, Ir, Au andlor Ag may be formed on the substrate. The magnetic layer has a highly improved signal:noise ratio, and excellent corrosion resistance compared with prior art materials.

Thick Film Resistors GTE COMMUN. SYST. U.S. Patent 4,796,356 Preparation of a thick film resistor on a ceramic dielectric substrate includes printing at least two resistor terminations to the substrate using a precious metal conductor consisting of a Pd-Ag compound. The resistor terminations are fmed by air drying and air firing at 85oOC. The resistors are used in ceramic hybrid microcircuits and can be made to close tolerance.

Stable Organosiloxane Compositions DOW CORNING CORP. U.S. Patent 4,801,642 Curable organosiloxane compositions used as confor- mal coatings and for encapsulation of electronic devices consist of an organosiloxane copolymer, an organohydrogensiloxane, and a metallic Pt or Pt- organosilicon compound catalyst to promote the hydrosilation reaction. Addition of less than Iwt.% of amines to the composition inhibits discolouration after curing, giving heat stability and long term storage stability.

~~ ~ ~~

A cathode is prepared by (a) forming a porous billet having 65wt.Yo W, 34wt.% Ir and ~ w t . % ZrH, activator, and impregnating with Ba aluminoiridate by firing in a H , atmosphere at about 1,475OC for 2 min. or (b) forming a porous billet by pressmg and sintering 70wt.% W, 29wt.% 0 s and xwt.% Zr hydride activator, and impregnating by contact with molten Ba 0 s , 0, in a dry H, atmosphere. A long life, high current density cathode is formed for use in mm wave and microwave devices.

High Current Density Cathode Preparation U.S. SEC. OF THE ARMY

U.S. Patent Appls. 7,215,081 and 7,224,980 A high current density cathode is obtained by impregnating a W - Ir billet with (a) a mixture of Ba, Sr and Al oxides, heating, and exposing the surface to vapour of an organ0 compound of Rh, Ir, 0s or Ru to deposit a 5,000-6,000 A layer on the billet, or (b) a low melting material having a melting point of 1,385-1,450°C, such as Ba,In,O,. A cathode having longer life and superior emission characteristics is obtained, for use in microwave and mm wave tubes.

Iridium Oxide Electrochromie Layer CANON K.K. Japanese Appl. 631282,720 An Ir oxide film is formed on a transparent electrode by repeating anodic oxidation several times on Ir films on the electrode. The method causes no film separation and produces an electrochromic device with an eletrochromic layer having high colouring and discolouring concentration change. The electrochromic device is used as a numerical display device, an X-Y matrix display and an optical shutter.

Metallising Composition for Low- Temperature Firing Ceramics NGK SPARK PLUG K.K. Japanese Appl. 631295,491 A metallising composition having IW parts wt. CuO+Cu, 20-80 parts wt. Pd and/or Pt, up to 10 parts wt. MnO,, and up to 5 parts wt. Ago, is used to form a metallised surface on low-temperature firing ceramics, as a low melting point, low resistance conductor material capable of fving simultaneously with the ceramics. It is used especially on the inner walls of through-holes of high density multilayer ceramic wiring boards.

Platinum Film Stabiliser for Superconductor

A substrate of AI,O, for making an Y-Ba-Cu-0 superconductor has a stabiliser to prevent chemical reaction between the substrate and the superconductor. The stabiliser consists of a Pt fdrn 3,000 A thick deposited by sputtering to make a compound substrate, which enables a chemically stable superconductor to be manufactured.

CHICHIBU CEMENT K.K. Japanese Appl. 631305,574


Platinum-Manganese-Lad Photomagnetic Recording Medium MATSUSHITA ELEC. IND. K.K.

Japanese Appl. 6313 I 6,339 A photomagnetic recording medium consists of PtMnPb and at least one of the rare earth elements Tb, Dy and Ho. The medium has improved vertical magnetic anisotropy, large Kerr rotational angles or large quantity of signals, and is capable of recording and reproducing information using laser beams.

Base Metal Powder Production TOSHIBA K.K. Japanese Appl. 64718 A base metal powder is produced economically from a base metal core powder (such as Cu) having particle size 0.1-20 pn, by activating the surface with Pd chloride solution, and applying a different base metal layer (such as Ni) on the powder. The powder has excellent oxidation resistance, high reliability, and is suitable for a layered ceramics capacitor electrode composed of base metal powder layers.

Metal Fibre Reinforced Superconducting Oxide Material HITACHI K.K. Japanese Appl. 113,909 A reinforced superconducting oxide material is a composite of an Y-Ba-Cu-0 superconducting oxide and metal fibres of Pt, Pd, Ir, Au, Ag, Moor W. The material is used for wire and coils, having improved strength and reliability.

Formation of Patterned Metal Plating on Printed Circuit Substrate ADACHI SHIN-SANGYO Japanese Appl. 1115,377 A vehicle of TiO, , ZnO, SnO, , Sic or CdS powder of 50-0.005 pn grain size, precipitated with a catalyst of Pt, Pd, Au or Ag, is applied to a substrate to form a printed pattern f h , which is allowed to harden prior to electroless plating. The method is used to form patterned metal plating on a printed circuit.

Perovskite Structured Oxide Superconductors TOSHIBA K.K. Japanese Appl. 1128,219 Perovskite structured oxide superconductors consist of at least one of Y, La, Sc, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb or Lu, at least one of Ba, Ca, or Sr, and Cu as well as Pt andlor Pd. The oxide superconductors obtained have high transition temperatures and current densities.

Glass Composition for Resistors

Ag-Pd conductors are used as contacts in the production of a glass composition for resistors, based on oxides of Ba, Si, B, Ca, Sn, Mn and Cu. The proposed glass can be used as a glass binder for thick fdm resistors, such as Sn0,-based thick fdm resistors, and can be used in radio and electronic techniques. A reduced noise level and voltage coefficient, and improved stability are obtained.

MOSC. ELTRN. ENG. INST. Russian Patent 1,418,301

MEDICAL USES Dental Composite Structure for Artificial Teeth KULZER & co. G.m.b.H. European Appl. 298,190A A dental material for making artificial teeth has a support of at least 20wt.% Ag, at least 20wt.% Pd, and at least 50wt.% total Ag+Pd, coated with a 10-150 nm thick heat protection layer of Au, Ag, Cr or others, a cover layer, and a f d plastic layer. There is no cracking between barrier layers, and the heat protection layer protects the Ag+Pd layer from separating and gives the composite a higher shear strength.

Low Toxicity Platinum Anti-Cancer Agents KURARAY K.K. European Appl. 307,827A New Pt complexes of dextran or hydroxyethyl starch have at least one carboxylated active site, and are useful as water soluble anti-cancer agents. Compared with known Pt-based anti-cancer agents, they cause fewer side effects, have a broader spectrum of action and stronger activity. There is not significant accumulation in normal tissue, and they are readily delivered to metastases in the lymphatic system.

New Platinum Anti-Tumour Complexes TORAY IND. INC.

Japanese Appk. 631303,987-88 and 631307,890 New Pt(I1) complexes used in anti-nunour drugs are (a) diaminocyclo Pt(I1) complexes; (b) cis- dichloro(L-3-aminoperhydroazepin) complexes; or (c) I ,2-cyclobutanecarboxylate (3-aminoperhydroaze- pine)Pt(II) compounds. The complexes can be ad- ministered in various forms at an adult daily dose of 0.01-50 mg, and d have anti-turnour activity with (a) and (b) having weak toxicity.

Palladium Foil Denture Making Matrix Superconductive Ordered Material Containing Atomic Pairs GIREDMET. RES. INST. Russian Patent 1,409,254

A denture making matrix is prepared from Pd foil of HITACHI K.K. thickness 0.02-0.025 mm, made from monocrystals

A high temperature superconductive Ordered with an orientation of (101)*2O which have been sub- material consists of a Cu-Ag-Au-Pd d o y with a jected cold deformation. denture making I-dimensional long periodical structure containing atomic pairs of Cu, Ag, Au and Pd with oxygen. Preparation of a superconducting material, having Tc of 77K or higher, is achieved without incorporating any rare earths or alkaline earth elements.

yapanese ~ ~ ~ 1 . 1/28,336

matriu uses less materials than one

The New Patents abstracts have been prepared from material published by Derwent Publications Limited.

of pt.


GIREDMET. RES. INST. Russian Patent 1,409,254

A denture making matrix is prepared from Pd foil of thickness 0.02-0.025 mm, made from monocrystals with an orientation of (101)*2O which have been subjected to cold deformation. This denture making matrix uses less materials than one made of F’t.

HITACHI K.K. Japanese Appl. 1128,336

AUTHOR INDEX TO VOLUME 33

Page Abdi, S. H. R. 90, 91 Abon, M. 24 Acres, G. J. K. 21 Adachi, G.-Y. 26 Adachi, H. 34 Adams, V. W. 174 Aizawa, M. 86 Akolekar, D. B. 144 Alcini, W. V. 34 Aldabe de Bilmes,

S. A. D. 84 Aldao, C. M. 92 Alekseeva, N. F. 146 Alessio, E. 92 Allemand, L. 216 Allongue, P. 216 Alnot, M. 137 Alston, D. R. 25 Al’m, L. Ya. 26 Al-Bazi, S. J. 147 Al-Dabbagh, R. K. 28 Anahara, R. 172 Anan’in, V. I. 29

Anderson, D. R. 12 Anderson, 0. P. 148 Anderson, W. A. 223 Andersson, C.-M. 146 Ando, H. 142 Anlage, S. M. 25 Ansermet, J.-P. 81 Antoniazzi, A. B. 214 Aoi, T. 222 Appleby, A. J. 170 Arai, K. 34 Arakawa, H. 90. 221 Aramata, A. 222 Arblaster, J. W. 14 Armgarth, M. 28 Arroyo, V. 90 Arulraj, I. 147 Arvia, A. J. 84 Arzhannikov, V. A. 215 Asada, T. I72 Asakura, K. 31 Axoli, A. 172 Aso, K. 25, 222 Attia, W. M. 92 Auerbach, R. A. 28 Auffermann, G. 26 Aurian-Blajeni, B. 2 16

Anbang, D. 35

Baba, N. 34 Baba, T. 219 Babenkova, L. V. 89 Badoz, P. A. 34 Bahatt, I. 84 Baiwchi, F. A. I48 Bakker, H. I38 Baller, T. S. 92 Ballini. Y. 34

Page Balzani, V. 85 Bamfield, P. 89 Bankston, C. P. 140 Bannwarth, W. 92 BBnslgi, T. 31 Bao, J.-B. 30 Baran, S. V. 89 Barbier, J. 139. 143 Bard, A. J. I39 Bardi, U. 213 Barnard, C. F. J. 162 Barnard, J. A. 137 Baron, F. I75 Baronetti, G. T. 88 Bartak, D. E. 84 Barteau, M. A. 144 Barton, J. K. 148. 223 Basset, J.-M. 220 Bastasz, R. 87, 217 Bastein, A. G. T. M.

90 Bastin, G. F. 138 Bava, E. 138 Bazhutin, Yu. V. 27 Bearzotti, A. 87 Becker, E. R. 46 Behrsing, T. 144 Belapurkar, A. D. 30 Bell, J. U. 35 Belova, I. D. 25 Beltramini, J. N. 29 Belyaev, V. D. 215 Belyatskii, V. N. 89 Benedict, U. 25 Bennett-Slavin, L. L.

I48 Berman, E. L. 22 I Bernal, S. 31 Berresheim, K. H. 218 Berthier, Y. 29 Bertolini, J. C. 24 Besson, B. 32 Bewick, A. 83 Bhardwaj, C. 27 Bhardwaj, R. C. 27 Bittins-Cattaneo, B.

83. 84 Blair, A. 86 Blanpain, B. 24 Blaser, H. U. 218 Blomen, L. J. M. J. 171 Boichinova, E. S. 83 Bonev, Ch. 29

Boodts, J. C. F. 140 Boone, D. H. 141 Borkowski, M. 28 Boronin, A. I. 30 Bose, R. N. 148 Bottger, U. 2 I4 Bournonville, J. P. 220 Bowles, J. F. W. 13

Bongers, J. 35

Bradshaw, A. M. Brailovskii, S. M. Branitskii, G. A. Bray, W. Bressan, M. Brewer, L. Bronger, W. Brown, R. L. Bruis, W. H. J. Bruneau, C. Bucher, J. P. Burke, L. D. Burkhardt, J. Buschmann, H. W. Buslaeva, T. M. Buttet, J.

Page 24

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218

Cain, B. L. 217 Caliendo, C. 87 Calligaris, M. 92 Cameron, D. S. 10 Candy, J. P. 220 Capith-Vallvey, L. F.

73 Carbajal, J. L. I40 Carcia, P. F. I77 Carr, M. J. 82 Caspar, J. V. 83 Castro, A. A. 88 Cattaneo, E. 83 Cayton, T. E. 217 Cervera-March, S. 140 Chabot, J. 9 Chakraborty, A. K. 86 Chandrasekaran, R. 147 Chang, C. C. I48 Chang, C. Y. 92 Chang, L.-D. 213

Chanjuan, X. 140 Chassot, L. 85 Chaudouet, P. I39 Che, C.-M. 32, 141 Chen, A. I80 Chen, J. 82 Chen, J.-R. 2 I3 Chen, M.-C. 223 Chen, N.-Y. I38 Chen, Y. 30. 82 Chen, Y.-J. 27 Cheng, C. H. 143 Cheng, T. F. 92 Chernikova, 1. E. 35 Chevallier, J. 91 Chiou, B.4. 34 Chitale, S. M. 92 Cho, B. K. 220 Cho, K.-C. 141 Chojnacki, T. P. 137 Choudhary, V. R. 144 Christensen, P. A. 215

Chang, P.-H. 34

Page Christou, A. 223 Chu, S. N. G. 223 Chumakov, V. G. 27 Chuvilin, A. L. 30, 218 Ciano, M. 85 Cieslak, M. J. 82 Cima, M. 84 Cocking, J. L. I27 Cole, H. S. 86 Cole, T. I40 Cole-Hamilton, D. J. 145 Colleuille, Y. 32 Comrie, C. M. 2 I4 Conesa, J. 217 Cooper, B. J. 61 Cordfunke, E. H. P. 215 Cordonna, G. W. 46 Cosnier, S. 27 Cottington, I. E. 12, 16.

20, 21, 23, 54, 60, 63, 72, 80, 105, 113. 116, 127, 168, 180. 193, 212

Courtine, P. 218 Cribb, S. J. 13 Crisafulli, C. I45

Coupland, D. R. 9

Dabos, S. 25 Damyanov, L. 29 Datta, R. 60 Dautremont-Smith,

W.C. 223 Davis, J. L. 144 De Almeida, S. G. 35 De Miguel, S. R. 88 De Reus, R. 92 de Rooij, N. F. 217 De Visser, A. 91 de Wet, D. J. 72 Dean, V. W. 24 Deb, P. 141

Demopoulos, G. P. 16 den Broeder, F. J. A.

I77 Denier Van Der Gon,

A. W. 81 Deronzier, A. 27 Derouin, C. R. 33 Deshpande, V. M. 145 Deuschel-Cornioley, C.

85 Devekki, A. V. 89 Dheenadayalan, S. 147 Diagne, C. 219 Diamond, S. E. 31 Dijkgraaf, P. J. M. 29 Dixneuf, P. H. I47 Domen, K. 30 Dooley, K. M. 143 Doornik, M. 0. 138

Deguchi, T. 220

Platinum MetaLc Rev., 1989, 33, (4) 232-236 232

Page Dovganyuk, V. F. 146 Doyle, M. L. 17 Drago, R. S. 31 Drozdov, V. A. 218 Dubrouillet, J. N. 140 Dufour, R. I74 Duplyakin, V. K. 26 Duprez, D. 143 Durand, R. 82, 139 Dud, R. 213 Dwight, K. 31 Dyer, C. I75 Dziedzic, A. 35 D’Amico. A. 87

Echavarren, A. M. Egan, J. M. Egashira, M. Ehrhardt, J. J. El Mansour, A. Emel’Yanova, G. I. Engler, B. Enyo, M. 26, Ericsson, T. Escaffre, P. Escudero, J. S. Esteruelas, M. A. Etspiiler, A. Evans, J. Evans, N. J.

Fan, F.-R. F. Farooq, M. A. Farrauto, R. J. Farrell, N. P. Faure, R. Felter, T. E. Felty, R. A. Feret, J. M. Ferla, G. FernPndez, A. Ferretti, 0. A. Fgoli, N. S. Filonenko, G. V. Fincher, C. R. Flanagan, T. B. Fleischmann, M. Flower, H. M. Fortunato, G. Franse, J. J. M. Freiser, H. Frenklach, M. Frolov, V. M. Fujimori, H. Fujimoto, T. Fujita, F. E. Fuiita. M.

146 214 23

137 220 88

I43 140 2 I4 32

140 83

I93 127 87

I39 I48 88 35 82

137 222 171 34

217 220

88 144 I77 82 54

106 87 91

147 24 32

I48 215

81 145

Fujitani, Y. 142, 144 Fukuoka, A. 215, 220 Fukusaki, Y. 82 Fultz, B. 25 Funakoshi, M. 144

Page Gaisenko, L. V. 26 Galle, J. E. 31 Gallezot, P. I43 Galvagno, S. I45 Galyamov, B.Sh. 25 Gao, Y. 92 Garrett, B. 137 Gatte, R. R. 137 Gdowski, G. E. 137 Gerasimova, L. V. 29 German, R. M. 35 Gernet, S. 217 Ghetta, V. I39 Gibbs, T. K. I27 Gileadi, E. 84 GimCnez, J. 140 Giner, J. 139 Gintovt, T. 1. 30 Giordano, M. C. 84 Gipe, M. L. 223 Girault, H. H. 86 Girushtin, G. I. 144 Godlieb, W. F. I77 Godone, A. 138 Goethel, P. J. 24 Golonka, L. 35 G6mez, R. 90 Gondlez-Elipe, A. R.

217 Goodenough, J. B.

147, 222 Gorbatsevich, M. F.

88, 143 Goroncek, K. 28 Goryachevskaya, A. V.

22 I Goswami, N. 148 Gottesfeld, S. 91 Grace, J. R. 216 Graetzel, M. 218 Graham, G . W. 218 Grau, J. M. 29 Gray, H. B. 141 Greenbaum, E. 27 Greidanus, F. J. A. M.

I77 Greiner, G. 85

Griffith, W. P. 181 Griffiths, K. 213 Grigorov, E. I. 218 Gritsenko, V. 1. 144 Grizan, N. V. 27 Grobovenko, S. Ya. 221 Gross, R. 223 Gruba, A. I. 35 Grumet, C. 9 Grunewald, G. C. 31 Gruss, R. 216 Gruzdkov, Yu. A. 85 Gryaznov, V. M. 219 Guczi, L. 89 Guenais, B. 34 Guenin, M. I43 Guida, R. 86

Griffin, R. B. 140

Page Guivarc’h, A. 34 Gul’yanova, S. G. 219 Guo, X. 214 Gupta, N. M. 30 Gur’yanova, 0. S. 219 Guseinova. A. D. 27

Haasz, A. A. 214 Hadj-Aissa, M. 143 Haen, P. 91

Halligudi, S. B. 90, 91 Hamnett, A. 91, 147,

222 Hanaoka, T. 90 Handley, J. R. 64 Hanley, L. 214 Hara, M. 35 Harada, H. 33 Harada, T. 217 Hards, G. A. 1 I4 Harriman, A. 28 Harris, M. R. 20 Harrison, K. N. 221 Haruki, M. 27 Harvey, P. D. 141 Hashimoto, K. 33 Hashimoto, N. 172 Hashimoto, S. 24, 222 Hatta, S. 34 Hayakawa, M. 25 Hayashi, K. 25, 138 Hayashi, Y. 33 He, J.-W. 213 Head, R. A. 32 Heal, G. R. 89 Healy, J. F. 215 Heijligers, H. J. M. 138 Heiland, G. 214 Heinrich, K.Kh. 30 Herrmann, S. 32 Hibiya, T. 138 Higaki, K. 83

Hills, C. R. 82 Hindermann, J. P. 219 Hirai, H. 85 Hirochi, K. 34 Hishinuma, Y. 33

Hallberg, A. 146

Higashino, H. 34

Hjorvarsson, B. 214 Ho, W. 82 Hoge, D. 24 Holleck, S. C . 216 Homeyer, S. T. 219 Hong, Q. Z. 213 Honji, A. 33 Horiuchi, M. 33 Hornung, C. 92 Hoye, P. A. T. 221 Huang, T. S. 92 Huang, Y.J. 29 Huck, R. 214 Huebener, R. P. 223 Hughes, R. C. 87. 217

Page Hung, L. S. 81 Hyoma, M. 138

Ichikawa, M. 215. 220 Idriss, H. 219 Igarashi, R. 85 Ignatenko, A. V. 221 Ignatenko, V. M. 146 Ikariyama, Y. 28, 86 Imanaka, T. 25. 90 Inomata, K. 24 Inoue, A. I38 Inoue, H. 142, 144 Inui, T. I45 Isaeva, V. I. I46 Ishigaki, Y. I45 Ishii, Y. 222 Ishikawa, M. 92 Ishikawa, W. 25 Ishino, M. 220 Itagaki, H. 32 Itaya, K. 83 Itoh, N. 170 Ivanova, Z. V. 86 Ivashchenko, N. I. 26 Iwakuro, H. 147 Iwasaki, Y. 25 Iwasawa, Y. 31 Iwasita, T. 215 Iyer, R. M. 30 Izumi, Y. 31

Jablonski, E. L. 29 Jackman, B. H. 216 Jackman, T. E. 213 Jackson, R. L. 86

Jakubowska, T. 141 Jalett, H. P. 218 Jeffries-Nakamura, B.

I40 Jenkins, J. W. I I8 Jiang, X.-Z. 30 Jin, J. 82 Jin, T. 31 Joh, T. 83, 220 Johnson, H. H. 25 Johnston, G. R. 127 Joon, K. 171 Jorge, G . 82 Jovanovif, T. S. 217 Junod, A. 92

Jaeger, H. 144

Kachurina, D. N. Kadaner, L. 1. Kadowaki, K. Kagarlitskii, A. D. Kaji, N. Kajihara, K. Katk , P. Ksmiya, N. Kanda, T.

35 86 91

22 1 222 82 32 84 33


Page Kaneda, K. 90 Kaneko, M. 85 Kaplan, G. 1. 25 Karlsson, E. 214 Karpinski, Z. 219 Karustis. G. 86 Kasemo, B. 214 Kaska, S. M. 139 Katsaros, N. 26 Katsnel’son. A. A. 24 Katsube, T. 35 Katz, A. 223 Kavanagh, K. L. 148 Kawamura, T. I38 Kawanabe, T. 223 Kawashima, A. 33 Kazanskii, V. B. 219 Kazee, B. 84 Kemmler-Sack, S. 223 Kennedy, B. J. 91 Kerr, J. M. 89

Khartonik, 1. A. 35 Khataee, A. I06 Kieffer, R. 31 Kiemel, R. 223 Kiennemann, A. 3 I , 2 19 Kikkert, S. J. 140 Kikuchi, E. 87. 142 Kim, J.-D. 141 Kim, K.-J. 141 Kimura, E. 215 Kishkinova, M. 81 Kita, H. 33. 139 Klein, C. F. 142 Kliger, E. G. 32 Knor, Z. 90 Knorr, R. 92 Kober, E. M. 83 Kobentein, E. 143 Kochubeeva, L. I. 27 Kwiman, 0. A. 2 I8 Kwl, B. E. 81 Kohl, D. 214 Kokh, I. G. 89 Kolar, R. M. 61 Kolmogorov, Yu. N. 221 Kolosov, P. E. 218 Komarov, V. S. 144 Komatsu, T. 222 Komiyama, H. 144 Kondo, T. I45 Konings, R. J. M. 215 Kosanovich, M. 46 Koskova, S. P. 144 Kost, K. M. 84 Koszi, L. A. 223 Koszykowski, M. L. 137 Koudelka, M. 217 Kovalenko, N. L. 27 Kovalev, 1. P. 22 I Kozlov, N. S. 88, 143 Krausz, E. 27 Kravchuk, L. S. 26

Khang, S.-J. 34

Page Kris’ko. 0. V. 24 Krozer, A. 214 Krylova, A. Yu. 88 Krylova, G. S. 83 Kuanyshev, A. Sh. 31 Kude, Y. 87 Kudo, A. 30 Kuech, T. F. 148 Kuhn, D. K. 25 Kul’chitskaya, T. Yu.

89 Kumar, C. V. I48 Kume, M. 85 Kumm, W. I74 Kummer, J. T. I40 Kunimoto, A. 54 Kupcha, L. A. 30. 143 Kurita, S. 27 Kuroda, T. I47 Kurogi, Y. 215 Kuwana, T. 84 Kuznetsov, V. L. 144 Kuznetsova. 1. L. 144

La Via, F. Lafait, J. Lahav, A. Lamb, J. L. Lambert, R. M. Lambert-Andron. Lamy-Pitara, E. Lanza, P. Lapidus, A. L. Lau, S. S. Lau, T.-C. Lawson, D. R. Lawton, T. J. Mdr, K. Leclercq, C. Lecomte, J.

Lee, B. H. Lee, H. C. Lee, J. W. Lee, W.-M. Lee, W.-0. Lee, Y. s. Legresy, J. M. Lemons, R. Lemos, F. R. Lennard, W. N. Lghouzouani, L. Liangbo. F. Lietz, G. Ligrani, P. M. Lim, C. J. Lin, C. C. Lin, 2. Lingjuan, Z. Linke, U. Lister, D. H. Littleiohn. D.

Lee, K.-S.

34 87

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LitvGkov; E. N. 31 Krishnan. K. M. 25 Liu, C.-C. 180. 216

Page Liu, J.-X. 30 Liu, Y. S. 86 Lo, H . 4 . 34 Lo Cascio. D. M. R. 138 Lobach, A. S. Lobadyuk, V. I. Loboda, T. P. Loeff, P. I. Long, E. C. Long, Y.-C. Lopez-Poveda, M. Loveland, M. E. Lovering, D. G. Loya, E. W. Lozinskii, N. S.

Luewnd, R. Lundstrom, I. Luo. H.

Luo, R. Lynch, S.

Lu, J.-T.

LUO, H.-Y.

30 32 25

I38 223

31 I45 I40 I69 217 35

216 85 28 25 90

I80 I93

Machida, K.4. 26. 140 Madar, R. Maestri, M. Maggiore, R. Mahe, R. Maksimov. B. 1. Malush, R. E. Malykh, 0. A. Mal’chenko, S. N. Mandler, D. Manninger, I. Manoharan, R. Mantese, J. V. Mardilovich. P. P. Marecot, P. Mares, F. Margot, E. Marmion, M. E. Marshakov, A. 1. Marshall, E. D. Martens, J. H. A. Martin, C. R. Marucchi-Soos, E. Marusyak, S. A. Maruya, K.4. Masai. M. Masuda, H. Masumoto, T. 54. 138 Matsuda, T. 87. 142 Matsuda, Y. 91 Matsui, F. 141 Matsumura-Inoue, T. 91 Matsuzaki, T. 90 Mayer, J. W. 24. 81.

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Mayer-Von Kiirthy, G. 223

Mayor, A. 84 McCabe. R. W. 88 McGill, 1. R. 105.

177. 185

Page Mclellan, R. B. 82 Mekhryakova, N. G. 146 Memmert, U. 213 Mertens, P. R. 218 Meshoyrer, R. 148 Meuldijk, J. 29 Meulenbroek, V. J. M.

91 Meyer, T. J. 83 Mikhailovskii, Yu. N. 26 Miller, M. M. I48 Millet, P. I39 Mita, K. 85 Mitchell, P. J. 88 Mitchenko, S. A. 221 Miura, N. 217 Miyagawa, K. 27 Miyama, H. 85 Mkayula, L. L. 89 Moiseeva, G. A. 27 Moldavskaya, N. A. 32 Mole, T. 144 Montes, H. 24 Monti, D. M. 218 Moran, G. 27 Mori, T. 33 Morita, M. 91 Moriyama, H. 141. 221 Morton, D. I45 Morvillo, A. I47 Mosseri, S. 28 Motoo, S. 33 Moutet, J.-C. 27 Moylan, T. E. 213 Mugerwa, H. N. 171 Miiller, F. 92 Miiller, P. 26 Munoz, A. 217 Munuera, G. 217 Muradov, N. Z. 27 Muraki, H. 142, 144 Murarka, S. P. 148 Muto, S. 81 Muzhumathi, S. 147 Muzychuk, R. V. 138

Nacamulli-Piran, L. Nagai, A. Nagamoto, H. Nageswara Rao, N. Nahor, G. S. Naito, S. Nakabayashi, Y. Nakagawa, Y. Nakajima, H. 33. Nakamura, J. Nakanishi, H. Nakano, K. Naoe, M. Napholtz, S. G. Narasimhan, C. S. Nardin, G. Natarajan, S. R. Nee, C. Y.

84 148 144 216 28

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Puge Neibecker, D. 22 I Nestroni, G. 92 Neta, P. 28 Neuimin, A. D. 215 Newson, E. 218 Ni, Z.-M. 142 Nichols, R. J. 83 Nieuwenhuys, B. E. 137 Nihei, Y. 213 Nikishin, G. I. 22 I Nikolskaya, L. V. 83 Nimz, M. 89 Ning, Y.-T. 138 Nishigori, S. 84 Nishihara, H. 138 Nishiyama, S. 219 Norton, P. R. 213 Nosaka, Y. 85 Noskov, Yu. G. 146 Noskova, S. P. 144 Nosova, L. V. 30 Notton, J. H. F. 13 Novhk, E. 31 Novsk, P. 215 Nowicka, E. 213 Nylandsted Larsen, A.

Nyrkova, A. N.

Ochiai, Y. Ocken, H. Ogawa, H. Ohnuma, S. Ohto, M. Ojima, I. Okada, M. Okuhara, T. Okuno, H. Omarov, Zh. T. Onishi, T. Onitsuka, K. Oppolzer, W. Oro, L. A. Orpen, A. G. Oshima, R. Osteryoung, J. Ota, K.4. Otsuka, K. Otto, F. D. Otto, K. Oudar, J. Oudet, F. O’Brien, L. A. O’Dea, J. J. O’Dwyer, K. J. O’Leary, W. A.

Pa& Z. Pafford, J. Palazov, A. Paliteiro, C.

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I47 Paneque-Sosa, M. 145 Papanicolaou, N. A. 223

Puge Parenago, 0. P. 32 Parera, J. M. 29, 88 Parmon, V. N. 85 Parsons, R. I70 Pattahiraman, R. 147 Pedersen, A. S. 91 Pepin, 1. 219 Perevalova, V. 1. 26 Perron, R. 32 Petrov, E. S. 146 Petty, M. C. 87 Phillim. J. 24. 29. 137 Philhtt, j . E. Pieck, C. L. Pineri, M. Pletcher, D. Ponaryadov, V. V. Ponec, V. Pons, S. Poon, C.-K. Popova, N. M. Potts, P. J. Pound, B. G. Pouskouleli, G. Pradier, C.-M. Prater, K. Preiss, D. Price, G. L. Prichard, H. M. Pringle, P. G. Prins, R. Prutchenko, S. G. Pryakhina, N. Ya.

58 29

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Pshenichnikova,A.B. -146 Pushpavanam, M. ~ 28 Pyatnitskii, Yu. I. 144 Pyle, A. M. 148, 223

Qinglin, L. 140 Qiu, W. I39 Querini, C. A. 88

Rajalakshmi, N. 214 Ramaprabhu, S. 214 Ramarao, K. V. S. 30 Ramnarayan, K. 145 Rangwala, H. A. 89 Rao, L.-F. 220 Rao, V. 60 Rastler, D. M. 171 Rau, H. 85 Rauh, R. D. 87 Rayment, T. 220 RCau, R. 22 1 Regina, F. J. 31 Regull, P. 84 Rehmann, J. P. 148 Reikhsfel’d, V. 0. 32 Richards, P. G . 127 Richardson, D. E. 35 Richardson, N. V. 213 Ricketson, B. W. A. 55 Riggs, V. G. 223

Puge Rijk, M. J. M. 29 Riley, B. 174 Rimini, E. 34 Robbins, J. L. I42 Roberts, G. G. 87 Rodriguez, M. 31 Rodriguez-Izquierdo,

J. M. 31 Roginskaya, Yu. E. 25 Ros, M. B. 83 Rose, J. W. 86 Rosencher, E. 34 Rosenstiel, A. P. V. 218 Rudakov, E. S. 146 Ruppert, R. 32 Russell, M. J. H. 60,

117. 186 Rustamov, M. I. 27 Ruzic, D. N. 217 RydCn, J. 214 Ryndin, Yu. A. 30

Saburi, M. 222 Sachtler, W. M. H. 219 Saegusa, S. 83 Saito, Y. 32 Sakakura, T. 22 I Sakamoto, A. I45 Sakamoto, Y. 82 Sal’nikov, V. S. 87 Samad, S. A. I47 Sanders, J. H. 60 Sandrini, D. 85 Sannier, J. 9 Santos, E. 84 Sanz, J. 217 Sarangapani, S. 139 Saris, F. W. 92 Sasaki, I. 222 Sasaki, Y. I47 Sassi, M. P. 138 Sato, N. 87, 142 Satoh, T. 138 Sava, G. 92 Savchenko, V. 1. 137 Savinov, E. N. 85 Saws, T. 24 Sbitnev, V. L. I38 Scanlan, T. S. 22 1 Scelza, 0. A. 88 Scheller, F. 216 Schembari, G. I45 Schmehl, R. H. 28 Schmidt, D. 92 Schmidt, L. D. 137, 145

Schubert, P. I43 Schwarz, J. A. 29 Schweizer, E. 24 ScirC, S. 145

Sella, C. 87 Semarge, R. E. 82 Semikolenov, A. S. 218

Schreiner, S. 222

SecouC, M. 34

Puge Sen, B. 30 Senateur, J. P. I39 Sen’kov, G. M. 29,

88, 143 Serein-Spirau, F. 32 Serfass, J. A. 173 Serov, Yu. M. 219 Serrano, J. L. 83 Sevostyanov, M. A. 25 Shan, X . Q . 142 Shao, M. J. 216 Shapovalova, L. B. 31 Shaprinskaya, T. M. 144 Sharf, V. Z. I46 Shaviv, R. 215 Shebut, S. 25 Sheu, L.-L. 219 Shevtsova, M. A. 35 Shibata, S. 28 Shifrina, R. R. 25 Shimazu, K. I39 Shimizu, Y. 23, 33, 222 Shimura, T. 148 Shinjoh, H. I42 Shinoda, S. 32 Shiokawa, J. 26 Shionoya, M. 215 Shirinskaya, L. P. 144 Shitova, N. B. 26 Shmidt, V. S. 91 Shoji, M. 148 Shorikov, Yu. S. 138 Shorokhov, N. A. 91 Shubert, U. 1 I7 Shuh, D. K. 27 Shuikina, L. P. 32 Shukla, A. K. 147, 222 Shulyakovskii,G.M. 146 Shul’ga, Yu. M. 30 Shutt, E. 1 I8 Shvets, V. A. 219 Shyu, J. Z. 218 Sidash, E. V. 89 Siddiqui, M. R. H. 147 Siera, J. I37 Silonov, V. M. 24 Simanova, S. A. 83 Simarro, R. I40 Sinfelt, J. H. 81 Singleton, S. T. 216 Skinner, P. E. 102 Skorobogatova, T. V. 24 Skov, K. A. 35 Skrigan, E. A. 88, 143 Skvortsov, N. K. 32 Slawin, A. M. Z. 25 Slichter, C. P. 81 Slyusarskaya, T. V. 86 Smith, M. B. 22 I Smith, R. J. 81 Smulek, W. 28 Sobczynski, A. 141 Sobyanin, V. A. 215 Sokolova, 1. G. 25 Sola, E. 83


Page Page Page Page

31 Tatarchuk, B. J. 60 Viniqra, M. 90 Worner. M. 85 Sololovskava. E. M. 25 Tarasov, A. L. 219 Vielstich, W. 83. 84, 215 Woo, H. S. 88 Solymosi, F. Song, J. I. Soria, J. Sotola, J. Souteyrand, E. Spetz, A. Spevak, V. N. Spirlet, J. C. Srinivasan, S. Stallard, R. L. Stangeby, P. C. Stankovif, B. S. Stark, D. S. Stasevich, V. P. Steckhan, E. Stevens, P. Stille, J. K. Stock, C. J. Stoddart, J. F. Stonehart, P. Strasser, K. Struzhko, V. L. Stulen, R. H. Suckling, C. J. Sugawara, S. Sugi, Y. Sugino, K. Suhr, H. Sullivan, B. P. Sumino, M. Sun, Y.-M. Suzuki, T. Swars, K. SzaM. A. Szentirmay, M. Szymura, J. A.

Taha, Z. Tainon, Y. Takabatake, T. Takahashi, K. Takahashi, M. Takahashi, N. Takahashi, S. Takahashi, T. Takanashi, K. Takao, Y. Takasu, Y. Takeguchi, T. Takemoto, T. Takemura, H. Takeuchi, K. Takeuchi, K. J. Takeuchi, R. Tamaki, J. Tamura, K. Tan, T.-C. Tanaka, J. Tanaka, K. Tanaka, M. Tanimoto, M. Taqui Khan, M

90. 91.

26 217 90

216 28 32 25

33, 63 92

2 I4 217

20 144 32

222 146 220

25 83

I74 144 137 89 83 90 87

193 2. 83

28 34

217 21 81

N. 26 89

86 I39 92

217 85 90

83, 220 85

148 23 91

145 90 33 90 26

I45 25

213 I80 33 91

143 . M. 27, 147, 216

90, 221

Temkin, 0. N. Terekhova, M. I. TQCnyi, P. Thoma, P. E. Thomas, G. Thomas, J. M. Thomas, P. M. Thomson, F. L. Thorez, A. Ticianelli, E. A. Tifouti, L. Tomohiro, T. Toshima, N. Toyuki, H. Trafas, B. M. Trasatti, S. Trimble, K. A. Trotimov, A. E. Trokhimets, A. I. Trost, B. M. Truong, T. B. Tsai, A.-P. Tselepi-Kalouli, E. Tsui, B.-Y. Tsuji, Y. Tsuruya, S. Tsyrul’nikov, P. G .

Tueting, D. R. Turro, N. J. Tiishaus, M.

I46 146 218 I42 I74 I 69 223

86 32 33

143 I48 85 85 92

I40 171 32 29

22 I 218 138 26

223 I45 219 87, 218 146 148 24

Uchida, Y. 222 Uemiya, S. 87, 142 Uemura, T. I48 Underwood, M. L. 140 Unertl, W. N. 213 Urbanovich, I. I. 30 Usami, Y. I72 Ushioda, H. 28, 86 Usselman, M. C. 129 Utuk, I. D. 145

Van Delfi, F. C. M. J. M. I37

Van den Broeck, H. 175 Van Der Klink, J. J. 218 Van Der Veen, J. F. 81 Van Der Wiele, K. 29 Van Dukum, P. H. 171 Van Os, G. H. 218 Van Sprang, M. 91 Vandenavyle, J. A. 82 Vannice, M. A. 30 Varlamova, T. V. 25

Vejux, A. 218 Vellone, R. 173 Verderone, R. J. 29 Vest, R. W. 92 Victori, L. 84

Vaska, L. 222

Vinogradov, M. G. Viscuso, 0. Vishnevskii, A. L. Vitomirov, I. M. Vlaev, L. Vlasenko, V. M. Vogel Koplitz, L. Volkov, V. I. Volter, J. Vol’fson, V. Ya. Von Zelewsky, A. Vorenkamp, T.

22 I 34

I37 92 29 30 27 35 89 30 85 91

Wacholtz, W. F. 28 Wada, S. 215 Wagner, F. T. 213 Wahren, M. 30 Walker, A. P. 220 Walsh, M. P. 170, 194 Wang, J. 33, 86, 139 Wang, P. 82 Wang, Y. 82 Wang, Z. 81, 139 Wanke, S. E. 89 Warburton, P. R. G. 127

Washay, M. 175 Watanabe, J. 148 Watanabe, M. 83 Watanabe, W. 33 Watanabe, Y. 145 Weaver, J. H. 92 Weber, W. H. 218 Wehrli, J. T. 218 Weiss, A. 214 Weixin, Z. 28, 217 Wells, A. 72

Wenzel, M. 148 West, D. R. F. I06 Westerveld, J. P. A. 138 Westphal, R. V. 142 Westrum, E. F. 215

White, J. M. 31 White, R. E. I40 Whitehead, P. I93 Whiteley, L. D. 26 Whitman, L. J. 82 Whyman, R. 32 Wibberley, B. L. 128 Wickham, D. T. 81 Wilcox, J. 86 Wilhelm, S. 83 Williams, D. J. 25 Williams, R. M. 140, 148 Williams, R. S. 27 Willner, 1. 141 Wischert, W. 223 Wold, A. 31 Wolfram, Z. 213 Wong, C. 88

Wasa, K. 34

Wenxia, T. 35

Wheeler, B. L. 140

Wu, J. Wu, N. L. Wu, R. L. WUU, Y.-M.

Xinhua, Z. Xu, H. xu, s.-Y. x u , x. L. Xue, J.

144 29

216 I39

I40 I38 30

218 29

Yabe, A. 141, 221

Yakushkin, M. I. 89

Yamamura, M. 25 Yamanaka, H. I38 Yamanaka. I. 33, 222 Yamanaka, K. 223 Yamashita, M. 33 Yamauchi, S. 28, 86 Yamazaki, T. 217 Yamazoe, N. 217 Yan, H.-Q. 2 I6 Yang, R. T. 24 Yates, J. T. 81, 214 Yavari, R. 82 Yeh, F A . 213 Yellowlees, L. J. 86 Yermakov, Yu. I. 144 Yibing, Z. 28 Yokoi, T. 217 Yokota, K. 144 Yokoyama, M. 85 Yoshihara, M. 82 Yoshikawa, S. 222 Yoshino, T. 34 Yu, J. Y. 222 Yu, L. s. I48 Yukiashi, T. 28, 86 Yun, Q. 35

Yaji, T. 35

Yamaguchi, 1. 220

Zakumbaeva, G. D. Zanashchikov, V. V. Zaretskii, M. V. Zarzycki, R. Zegers, P. Zeper, W. B. Zhang, L. Zhang, Z.-D. Zhen, Y. Zheng, L. R. Zhengshi, C. Zhensheng, J.

Zhou, Y. Zhu, J.-Z. Zielinski, S. Zilko, J. L. Zink, J. I. Zonet. S.

Zhou, X.-M.

31 22 I

26 25

I73 I77 142 31

I38 81

I40 140 I38 31

138 141 223 21 92


SUBJECT INDEX TO VOLUME 33 a=abstract Page Absorption, spectra, of Pt(phpz), , Pt( 100)-CO, a 24. 85

Acetals, acetaldehyde dialkyl-, formation, a I46 Acetic Acid. Anhvdride. Acetvls. BP olant 168

Acetaldehyde 33, 60

- I . Acetone, hydrogeAation, ‘a Acetylene, reactions with Pd catalysts, a Adsorption, C, S, effect on H-Pd permeation, a

89.

CI, on Pt electrode, in 0 reduction, a CO, 0, on Pt, Pd, a EtOH. on Pt electrodes, a H, on Pt electrodes, sulphurised Pt, a H, D, in Pd, hydride formation, a HCI, +H, +H,O, on P t ( l l l ) , a NO, on Rh(100). a

Alcohols, allyl, hydroformylation, a aqueous, photocatalytic dehydrogenation, a benzyl, electro-oxidation, a butyl, from propene hydroformylation, a ethyl. for H production, a

81, 129,

84,

oxidation on Pt electrodes, a

30 I46 214 I39 219 83 139 213 213 82 90

I 40 27 I43 I45 83

production, a 32, 220 isopropyl, reactions with H,PtCI,, PtCI,, a 26

84 adsorption on PdlCeO,, SiO,, TPD, a 219 catalysts for exhaust control, a 88 conversion to aromatics, a 144 decomposition on Pd, CO desorption, a 214 dehydrogenation, a 32, 85 for acetic acid, ace$% anhydride I68 for H, in Hot Spot reactor 1 I8 fuel cells, a 33, 91 oxidation, on Pt, Pd, a 26, 33, 83, 84, 139 preparation, on Pd/SiO, +Fe, MgO. a 89 waste, for H production 58

methyl, +H,O, for H photoproduction, a 141 oleyl, production, a I45

220 photoreactions, with Pt complex, a 141 production from hydrocarbons, a 32 secondary, oxidation to ketones, a 147 selective oxidation. by Ru(1V)-phosphine, a 26

91, 143, 144, 145, 221 see also Acetaldehyde, Formaldehyde,

222 Alkali Metal Thermoelectric Converter, a 1 40 Alkanes, a 32, 144, 147 Alkenes, a 32, 89, 186 2-Alkoxy 1,3-Diene, production, a I46 Alkyl Vinyl Ethers, vinylation with enol triflates, a 146 Alkynes, a 89, 147 Allylic Acetates, electroreactions with carbonyls, a 139 Aluminium, Pd thin films on, a 81 Aminonitriles? production, on RhlMgO, a 31 Ammonia, oxidation, catalyst gauze etching study 12

production, a 27. 216, 220 sensors, a 28, 217

Andrussow Process, catalyst gauze etching study 12 Antimony, a 142, 143 Arenes, C-C bond formation reactions I86

144 Aromatisation, n-hexane, a 30, 143, 218 Arsenic, detection, a 142

a-Keto Esters, hydrogenation, a 218

Battery, redox, rechargeable, with Ru complexes, u 91 Benzaldehyde, production, a 27 Benzene, a 90

220 Bicarbonate, photoreduction, a 141 Bonding, Pt wire wedge, for IC, microsensor, a 34

methyl, on Pt(IOO), R(l1 I ) electrodes, a

phenyl, synthesis, on Co-Rh, a

Aldehydes, a

Benzaldehyde Alditols, for aldonolactone synthesis, a

Aromatics, production from MeOH, a

2-Arylethanols, synthesis, a 220

Benzyl Halide, reaction with CO/H. a

Page

Chemistry I I7 Combustion Research in Japan, Vol. 5 I05 Geo-Platinum 87, symposium 13

21 Boundary Layers, subminiature sensor for, a I42 BP Chemicals Ltd, acetic acid, plant I68 Bronzes, W doped with Pt, a 26 1,3-Butadiene, catalytic reactions, a 29, 89 Butane, oxidation, by Pt black-MO,, a 87 Butyraldehyde, formation, a I43

Cadmium 84, 193 Cancer, antitumour properties of complexes. a 35, 92

cisplatin, carboplatin drug therapies I62 Pt pyrimidine greens, one-pot synthesis, a 148

Carbalkoxylation, C,H,, a 146 Carbon, C-C bond formation reactions I86

C,-0 compounds, synthesis on Rh/V,O,, a 90 effect on H-Pd permeation, a 2 I4

Carbon Oxides, CO, adsorption, oxidation on 81, 137

adsorption on Pd/SiO,. Pd size effect, a 219 concentration sensor 180 disruption of RhlAl , 0, , NO effect on, a 3 I effect on propene-D exchange reaction, a 143 emission control from gas turbines 46 for NO, reduction on Pt foil, a 81, 138 from MeOH decomposition on Pd(l I I ) , a 214 hydrogenation, for Rh,, RhFe zeolite, a 220 hydrogenation, a 31, 88, 142, 144, 219 in MeOH synthesis, a 89 oxidation, a 219, 220 poisoning of Pt in fuel cells, a 91 Pt-C stretch mode, in Pt( I I 1 )-CO spectra, a 24 reactions with H, a 144, 219, 220

CO, CO, , reduction on Ru pyrolysed polyacrylonitrile, a 31

C O , , greenhouse gas 194 hydrogenation, on Pd/La,O, , a 30 reaction with alkynes, a 147

222 sensor, portable, cheap I27

Carbonylation 90. 145, 168 Carbonyls, addition to allylic acetates, a I39 Carboplatin, anti-cancer drug therapy I62 Castor Oil, hydrogenation, a 147 Catalysis, heterogeneous, a 29, 30, 31, 87, 88, 89,

90, 142. 143, 144, 145, 218, 219, 220

a 32, 90, 91, 145, 146, 147, 221, 222 61, 143, 194, 218

CeRu,, CeCo,: CeFe,, NH, synthesis, a 220 Co-Rh bimetallic. 2-arvlalcohol. a 220

Book Reviews, Advances in Metal Carbene

Gmelin Handbook of Inorganic Chemistry

Pt( I I I ) , Pt( 110). S/Pt( I 1 I ) , a

reduction, electrocatalytic, to fuels 2 reduction to CH,, via formamide. a

homogeneous, for COI electroreduction 2

Catalysts, automotive exhaust

. , Honeycat@ in fuel cells, review 63. Ir, Rh/AI,O,, S O , , microstructure, a Iridium Complexes, Ir(CI)(CO)(Ph,P), , a Ir/AI,O,, preparation, a 29, Ni-Cr, Pd, F’t additive effects, a Palladium, gauze damage, in HNO, reactor, a

in combustible gas sensor modified, 1.3-butadiene diacetoxylation, a

Palladium Alloys, Pd-Mn, styrene oxidation, a Palladium Complexes, C-C bond coupling

metallo-ene reactions, a organo-Sn coupling with vinyl epoxides. a PdBr, -LiBr-MeOH, ethylene oxidation, a PdBr,-P(OPh),-n-BuOH, formation, a PdCI,(PPh,),, a 139, 146, PdCl , -CuCI , -LiCI, ethylene oxidation, a

I78 I69 145 222 143 144 88 180 89 30 186 145 146 146 146 22 I 146


Catalysts (conid.) Page 22 I

Pd(dba),:2PPh1, arene-alkene coupling 186 Pd(II), thiophene oxidation, a 146 Pd(lI)+salen, alkyne, hydrogenation, a 89 Pd(OAc),, Pd(PPh,), , vinylation, a I46

Pd,(dba) ,L, arene-alkene reactions I86 phosphine-Pd, fluoro olefin, reactions, a 90

Pd acetate, heterocycle’s formation 186 Pd,Mo/WO /W, reaction with N, a 90 Pd, Rh, RukiO, , D exchange, a 143 PdCI,-CuCI, in SiO,. Wacker process 60

144 Pd(NH,),’ INaY, calcination study, a 219 Pd+La,O,la-AI,O,, cycled NO reduction, a 144 Pd-alizarin cly-Al,O ,, hydrogenation, a 30 Pd-CelAl,O,, Ce effect on CO oxidation, a 219 Pd-MglX-zeolite, ethylene dimerisation, a 2 19 Pd-B-cyclodedrins, photoreduction of HCO- , a141 Pd/AI,O,, Ce effect on CO oxidation, a 219

HCI effect on activity, a 29 with H absorbed layer, hydrogenations, a 89 S O , , vinylacetylene hydrogenation, a 30 films, CH, oxidation, a 89

PdlC, preparation, surface properties, a 89 PdlCd),, TPD after MeOH, adsorption, a 219 Pd/La,O,, SiO,, La-PdlSiO,, for CO,

hydrogenation, a 30 Pd/SiO,, CO adsorption, Pd size effect, a 219

in H reactor I I8 +MgO, Fe, for CO+H reaction, a 89

PdITiO,, hydrogenation of CO, aldehydes, a 144 Pd/TSVM,/TSVK zeolites, xylene, reactions, a 144 phase-transfer, Pd extraction, a 147 Platinum, black 87, 180

colloidal +polytungstate, a 27 foil, CO+NO, reaction, a 81. 138 modified, 1.3-butadiene diacetoxylation, a 89 0 reduction, a 82 poisoning in PEM fuel cells, a 91

tunnelling, in graphite hydrogenation. a 24 Platinum Alloys, oxidation gauzes 12, 88 Platinum Complexes, H,PtCI,-Ln(NO,),, a 218

H ,hCl &-(C &H j lN-(i-C,Hq), AIH, a 32 metallo-ene reactions, a I45 PtCI,(PPh,),, Pt(CO),(PPh ,),, iodide

carbonylation, a 145 Pt(lI), Pt(1V) ethyl, decay in iodide

solutions, a 22 I Pt(phpz), , Pt(phpz)(thpy), luminescence, a 85

[PtH(PEt,),l , H production, a 145 [PI , (P, 0 I H ,), 1 ‘-. photoreactions, a 141 [Pt2(RzS0),X,1, activity, a 32

Platinum Metals, gas turbine emission control 46 Pt clusters, in EDTA/Ru(bpy) MV”. H

photoproduction. a 85 Pt, Pd, Rh, Pd-Ag, AI,O,, MeOH exhaust, a 88 Pt, Pd, Rhla-Al,O,, propane, oxidation, a 142 Pt, Pt-Ir/Al,O,, preparation, a 29 Pt, RulPdlVlPdlAl, H oxidation, during

reactor accident, a 86 Pt, -Re, -Re-S/AI,O,, reforming, a 29 Pt,-RhlAl,O,, La doped, exhaust, study. a 218 PTFElR metallsubstrate, isotope exchange, a 30 PtZn,.,,Cd,., S/Cu,S, photocatalysts, a 85 Pt-Crl,Pt-SnlAl,O, , n-pentane,

methylcyclopentane conversions, a 29 Pt-CrlSiO,, in H reactor I I8 Pt-impregnated glass membrane,

Pt-Re-Cr/Al,O,,ly-Al2O1, n-heptane

Pd(0). pumiliotoxin synthesis, a

Pd-P(CH,OH),, a 22 1

PdQII), popmerisation, of aldehydes, a

gel, CO hydrogenation, a 144

powder, passivating oxidation, a 88

Pt-P(CH,OHk,, a 22 I

cyclohexane dehydrogenation, a 34

dehydrocyclisation, a 88. 143

Catalysts (conid.) Pt-RelAl,O,, coked. sulphided, a Pt-Rh gauzes, in HNO, production, a Pt-RhlAl ,O ,. gas turbine emission control Pt-SblAl,O,, Pt-Te/Al,O reforming, a Pt-SnlAl,O,, after redox cycling, a Pt-TiO,, in H photoreactor, a Pt-TiO, thin filmslglass, photocatalyst, a Pt.H-ZSM-S.AI,O,, mass transfer effects, a PtlAI,O,, CO hydrogenation, pathways, a

coking, a HCI effect on activity, a hydrogenation of a-keto esters, a S resistance, hydrogenolysis, a SiO,, TiO,, C, NMR study, a S O 2 , passivating oxidation, a

PtlC. deactivation, in oxidation, a fibre, for C$l hydrogenation, a

PtlCdS, for [Ru’(H-EDTA)N,l-, a surface composites,

photodehydrogenation, a PtlFecralloy, in CO, TEA lasers PtlH-ZSM-5 zeolite, olefin hydrogenation, a PtlKL-zeolite, aromatisation of n-hexane, a Ptlphotosynthetic membrane, a Ptlsilicalite, preparation, a PtlSiO,, sintering, during C,H, oxidation, a PtlTiO, , acetone hydrogenation, a

photo, in MeOH fuel cell, n powder, H production, a

Pt/X-zeolite+Re, W, Mo, n-hexane dehydrogenation, a

Ptly-Al,O,, preparation, pH effect, a

RhFelNaY zeolite. structural characterisation. Pt dispersion study, a

Page 88

218 46

143 88

1 40 85

144 142 143 29

218 143 218 88 29 88

216

140 20

144 218 27 89 29 30 33 30

30 142 218

a 220 Rhodium, diacetoxylation of I ,3-butadienc. a 89 Rhodium Complexes, CoRh(C0) , . for fluoro

olefin reactions. a 90 Rh -r I promoter, acetyls production I68 RhCI(CO)(PR,), . irradiated C-H bond

activation, a 90 RhCI(PMe,), , vinylketones dimerisation. a 22 I RhCl ,/SiO,, nitrobenzene reduction. a 146 RhH(CO)(PPh ,) , +laser irradiation.

olefin hydrogenation. a 141, 221

Rh(ll), carbene insertion in 0-lactams. a 148 Rh-, Rh,-(TPPTS), two-phase, alkene

Rh(diphos),+, for CO, reduction 2

32 h droformylation, a RhA(C,Me,)(bpy)”. NAD(P) +

reductions, a - 32 Rh,(CO),,, fluoro olefin

hydroformylation. a 90 [RhCI(COD)I ,/SiO,, nitrobenzene

reduction, a . I46 [RhH(CO)(PPr’,),l, irradiated for H, a 145

2 [Rh(bpy),lCI, H production, a 145 [Rh(CO) ,CI1, + phosphanorbornadiene,

Rh(C0) clusters/PS, animated, N - 0 bond

Rh+SelZrO,, ethene hydroformylation, a 31 Rh-Felgraphite, surface structure, a 137 Rh-Ptly-Al,O,, preparation, pH effect, a 142 Rh-SnlSiO, , ester selective hydrogenation, a 220

220 31

RhlCdS, for [Ru’ (H-EDTA)N,l-, formation, a 216 RhlMgO, dinitrile hydrogenation, a 31

220 RhlSiO,, C,H, hydroformylation, conditions, a 90 Rhlsupport, L,a,Ol promoted,

CO hydrogenation, a 31 Rh/V,O,, C , -0 compounds synthesis, a 90 Rhly-Al,O,, preparation, pH effect, a 142

[Rh(bpy) ,X , 1 -, CO, reduction

hydroformylations, a 22 1

deoxygenation, a 90

RhlAI,O,, CO oxidation, dissociation, a effect of NOtCO disruption, a

RhlNaY zeolite, olefin hydrogenation, a


Catalysts ( c o d . j Page Rh,(CO),,lNaY zeolite, structure, a 220 RuO, +LalZrO,, preparation, stability. a 31 Ruthenium, NH , production. from N, . a 27

tunnelling. in graphite hydrogenation, a 24 Ruthenium Complexes, cis-[Rulll(L),(OH ? ) , I +.

HC oxi tion, a 32

hydroformylation. a 90 RuCI,-,RuCI,, norbornadiene, arenes.

for vinyl carbamates. a I47 RuH ,(PPh , ), , aldonolactone synthesis. a 222 Ru(lI1)-EDTA. hydroformylation. a 91 Ru(I1) + hypochlorite, a 147 Ru(OAc)CI(PEtPh,) , + Li.

MeOH dehydrogenation, a 32 Ru-Co system, EtOH production, a 32 [H,RuCI,(ASP~,)~I . oil hydrogenation, a 147 LRu~,(N?)(PPh,),I, H production. a 145 IRu VO(bipy),(ERJ)l~+C, alcohol oxidation. a 26

Ru(bpy), z'lEDTA/MV* ', Pt clusters. H photoproduction, a 85

Ru-Co-MnlAl,O,, composite, high calorific fuel production. from syngas: a 145

Ru-Cu/Al,O,, syngas conversion, a 31 MgO, SiO,, propane hydrogenolysis. a 145

Ru-CulSiO,, H, chemisorption, a 31 Ru-PdlSiO,, synergism in C,H,

hydrogenation, a 90 Ru-Sn-BlAI,O,, oleyl alcohol production, a 145 Rulpyrolysed polyacrylonitrile,

CO,CO,, reduction, a 31 RulTiO, powder, H photoproduction, a 141

Cerium, a 143, 218 Cermets, Pt-AI,O, film. spectral selectivity. a 87 Chemisorption, H,, on Ru-Cu/SiO, , a 31 Chlorine, adsorption, on Pt electrode. a I39 Chloroplatinic Acid, a 26 Cholinesterase, activity in human serum, detector. a216 Chromium, dissolution rates, a 26

88. 143 141

Cisplatin, anti-cancer drug therapy I62 Coatings, Cr modified Pt aluminide, a 141

Pd, of stainless steel in nuclear reactors I85 Pt, on steel, slide wear 12 Pt, Pt alloys, for industry. jewellery I02 Pt modified aluminide, on gas turbine blades 127 Rh, thin films, by plasma enhanced CVD I93

Cobalt, dissolution rates, a 26 in ColPt magneto-optics 177, 222 MCo, in Pd coated steel, in reactors I85

Coking, in Pt/AI,O,, a 143 Cold Fusion I14 Colloids, Ir oxide + RuO,. a 28

Pd-8-cyclodextrins. HC0,- reduction, a 141 Pt, for H, photoproduction. a 27

Colombia, historical metallurgy 73. 80 Composites, for ORINEL electrodes, a 216

Pd thin filmlporous glass, water gas shift reaction, a 87. 142

SPE, with Ir, Pt species, H,O electrolysis, a 139 surface layers, Pt, CdS, photocatalytic alcohol

dehydrogenation, a 140 Conferences, 26th Champion Ignition and Engine

I05 Chemistry of the Platinum Group Metals,

1990, announcement I16 Electrochemical Society, California, May 1989 I13 Geo-Platinum 87, proceedings 13 Grove Fuel Cell Symp.,

I69 Int. Symp. Metal-Hydrogen Systems, 1988 17 National Fuel Cell Seminar, 1988 10 SAE Int. Congress, Detroit, 1989 61

Copper, electrokss plating, a 86

KIRu P ' "(EDTA-H)CII .2H,O.

effect on Pt+Re+Cr/y-Al,O,, a modified Pt aluminide coatings on Ni, a

Performance, Munich, 25, 26 April 1989

London, 18-2 1 September 1989

Page Corrosion, CI- adsorption.+H.+H,. on Pt( l l l ) . a 213

hot. of Cr modified Pt aluminide coatings, a 141 in Pd-Ag dental alloys, a 35 Pt anodes in H,SO,. a 84 Ti-Pd surfaces, a 82 (TiwRu,o)nSi,J, in saline, a 140

Cracking, isooctane, a 144 Crystallisation, PdSi, PdGe. H dissolved in, a 82 Crystals, cis-RuCI,(DMSO), , a 92

Ln,Ru,,P,,, a I39 quasi. Al-Cu-Ru, a 138 single, Pt(100). Pt(l1 I ) , MeOH adsorption, a 84

Pt-Ni, surface characterisation, a 24 TiO,. surfaces. Pt thermal deposition on. a 213 [Pt(en),I[Pt(en),CI,1(CIO,),, photo defects, a 27

Cyclic Voltammetry, a 84, 85 22 1 22 1

Cyclohexane, dehydrogenation reactions. a 34. 88. 143 from aromatisation of n-hexane, a 218

Cyclopentane, reactions over Pt, Ir/Al,O,. a 143

144 Dehydrocyclisation, n-heptane, a 88, 143 Dehydrogenation, aqueous alcohols, a I40

cyclohexane, a 34. 88. 143 cyclopentane. a 143 MeOH, a 32. 85 n-hexane, a 30

Deoxygenation, N - 0 bonds, a 90 Detectors, boundary layer measurements, a 142

CO , . portable. cheap 127 fish freshness 23 for H, HC, CO concentrations 180 glucose, a 217 glucose, saccharides, micro-enzyme, a 28. 86 H, a 28, 87. 217 heat transfer probe, for circulating fluidised bed, a2 16 H,S, by Pd gate MOS, a 28 H,O+, by Pt polypyrrole electrode, a 141 in spark ignition engines. book review 105 NH,. a 28. 217 N-acetyl-L-cysteine in H ,0. a 217 0, fast response, a 216 organic gases, with Rh probe, a 142 Pb, Cd, Sn in food slurries 193 proton, a 87 temperature, thin film Rh-Fe. cryogenic use 55

213 exchange reaction with propene, CO effect, a 143 isotopic exchange, on PTFEIPtlsubstrate, a 30 permeation with H, through Pd-Fe, a 25

Diacetoxylation, on Pt, Pd, Rh, a 89 Diesel, engines, pollution control 61

for H production, in Hot SpotTM reactor 118 Diffusion, barrier, Ta,N between Pd,SilAl. a 148

H, D, in Pd, Pd. alloys 17, 58, 82. 137. 213 Si, in Pd,Si, a 214 see also Permeability, Solubility

I, 5- Diketones, synthesis, a 91 Dimerisation, a 215, 219, 221 Dinitriles, hydrogenation, on RhlMgO, a 31 Diactyl Sulphide, for Pd extraction, a 147 Diodes, a 217. 223

35, 92, 148. 223 DNA, a D-gluconate, oxidation, a 29

E.E.C., exhaust emission control laws 194, 212 Ecuador, historical metallurgy 73. 80 Electrical Contacts, AllPtSiln '-Si, resistivity. a 91

GelPd, Au-Ge-Ni. to n-AIGaAs, resistivity, a 148 Pd-n-GaAs, high temperature behaviour, a 92 PtlTilp-InGaAs, low resistance, a 223 see also Sehottky

Cyclisation, to give pumiliotoxin. a Cycloalkylation, vinyl epoxides. a

Decarbonylation, aldehydes, on Pd(II1). a

paraffins, irradiated. a 90

Deuterium, adsorption in Pd, a


Electrochemiluminescence, Ru(bpy) , +, dc, a 85 Electrochemistry, a 26, 27, 83. 84, 139, 140, 215, 216 Electrwhromism, in 110, thin films. a 34, 223 Electrodeposition, a 28, 86, 87, 141

86 I02 28 84 83

91, 222 dissolution in H,SO,, a 84 for MeOH oxidation, a 83 in fusion reactions 54

cathodes, Al sheet, Ru(bpy) , + ECL, a 85 110 H evolution on, a I40

disc, Pt, Rh effects on dissolution rates, a 26 in solid state fusion I14 microplatinised, glucose, saccharide, a 28, 86 micro-, for glucose sensor, a 217

Pt, cylindrical, behaviour, a 216 ORINELs, with Ir oxide, polyaniline, a 216 Pd, Pd-Au, phase changes in hydride formation, a140 Pd, +Cd, TI, cyclic voltammetry, a 84 Pd-Ag, oxidative dimerisation of CH,, a 215 photoanodes, n-GaAs, stabilised with Pt grains. a216 Pt, allylic acetates electroreduction, a I39

EtOH oxidation on, a 83 hydrous oxide formation in acid, a 215 in H sensor, a 217 polyaniline deposition, a I39 Pt-AI surface alloy formation. a 84 glassy C, polypyrrole, for propylene

carbonate oxidation. a 215 metallised thick film, for cholinesterase

activity, u 216 rotating ring disc, 0, reduction on, a 33, 139

Pt phthalocyanine/C, fuel cell, evaluation, a 147 Pt polypyrrole, as H ,O+ sensor, a 141 Pt + adatoms, in formic acid fuel cell, a 33 Pt + CoTMPPIC, 0 reduction in fuel cell, a 222 Pt(100) electrofaceted, stabilisation in acid, a 84 Pt(100)/Pt foils, a 28 Pt(l I I ) , Pt(100). MeOH adsorption on, a 84 Pt-Mo-SPE, for MeOH oxidation, a 33, 139 Pt-SPE, H z O electrolysis, a I39 Pt-W bronze, for MeOH oxidation, a 26

33 Pt/Nafion, 0 reduction at, a 26 PtlNi, porous gas diffusion, evaluation, a I47 PtlPA/glassy C, H evolution, a 84 Pt/poly[RuL,Iz +-RuOz, oxidation reactions, a 27 Pt/PTFE, in CO, sensor 127 Pt/Ru. Pt(1V) species, in acid media, a 215 with thin polymeric films, for CO, reduction 2 WPt, WRh, in thermoelectric converter. a 140

Electrolysis, H,O, by Ir, Pt in SPE, a I39 Electronics, Pt, Pd powders for 16 Electroplating, a 28, 86, 102 Emission Control, 1989 SAE Int. Congress, Detroit 61

1992 E.E.C. standards 212 catalysts, book review 105

CeOl effects on, a 143 gas turbines 46 MeOH fuelled vehicles, a 88 motor vehicles, greenhouse effects I 94 print industry drying gas 178

Energy, solar, converter, a 85

Enol Triflates, reaction with alkyl vinyl ethers, a 146 Environment, protection 178, 194 Erythrocytes, detector, a 216 Esters, a 145, 146, 147, 220

Electrocatalysis, CO, by thin polymeric films

Pd-Ni alloys, from sulphamates, a

Pt films, from solution, a Pt microparticles, on PAlglassy C electrodes, a Pt on graphite, STM study, a

Pt. Pt alloys, new baths

Electrodes, anodes, Pt, in MeOH fuel cell, a

Pd,% fusion reactions 54

Pt/C, in SPE. HJPO, fuel cells, a

Engines, combustion, book review I05 design, conference, Munich, 1989 I05

Page Etching, Pt, a 12. 24 Ethers, oxidation. by Ru(1I) complexes. a 147

220 22 I

Ethylene, conversion to CH ,CHO. Wacker process 60 29, 31, 89, 90, 146. 219, 221

Extraction, Pd, by phase-transfer catalysis. a I47

Films, 110,. a 25 Pd/SiO,/Si, H effect, a 87 Pd/MIS, Langmuir- Blodgett. a 87 Pt on polycrystalline Pt foil, for electrodes, a 28 Pt-AI,O, cermet, spectral absorption. a 87

Fischer Tropsch, a 31 Fish, freshness detector 23 Fluoro Amino Acids, synthesis, a 90 Formaldehyde, MeOH fuelled vehicle, a 88 Formamide, intermediate in C 0 2 to CH,, a 222 Formate, production 2, 141 Formic Acid, adsorption, oxidation, a 219 Fuel Cells, a 33, 91, 147. 222

alkaline, PtPc/C. Pt/Ni electrode evaluation. a 147 33

formic acid, with Pt+ad atoms electrodes, a 33 Grove Symp.. London 18-21 September 1989 169 methanol, a 33, 91. 222 National Fuel Cell Seminar, 1988 10 PEM, catalyst poisoning, a 91 phosphoric acid, a 33, 222 review 63, 169 SPE, electrodes, a 33. 222

Fuels, alternative, book review 105 high calorific, synthesis from syngas. a I45 in engines, conference, Munich, 1989 I05

Furnaces, Pd coated, for As, Sb. Se detection, a 142 Fusion, solid state I14

9

Ethyl Acetate, hydrogenation to EtOH. a Ethyl Acrylate, hydroformylation, a

reactions, a

amorphous Ni alloy catalysts, a

Fusion Reactors, H purification for

Gas Turbine Engines 46. Gases, organic, sensor for, a Gasoline, Pb-free, for H production, Gauzes, catalytic 12. 88. Generators, H, Hot SpotTM reactor Geology, Geo-Platinum 87. conference report Germanium, Si,Ge,-,, reactions with Pt, a Glass, porous, Pd, plated composite, a

reactions with binary Rh alloys Vycor membrane, Pt impregnated, reactor, a

Glucose, detectors, a 28, 86, Gmelin, technology of the platinum group metals Graphite, hydrogenation, by tunnelling catalysts, a Greenhouse Effect, caused by motor exhausts Grove Fuel Cell Symposium, London

127 I42 I I8 218 I I S 13

213 87 64 34

217 21 24

I94 I69

Halides, organic, photoreactions, a 141 Heavy Water, production. a 30 1-Heptaldehyde, formation, a 91 Heptanal, production, a I45 n-Heptane, dehydrocyclisation, a 88, 143 Heterojunctions, micro, for H production, a 85

n-Hexane, catalytic reactions, a 29, 30, 143, 218 1-Hexene, hydroformy lation, a 91

73 Honeycat@, catalyst used in print industry I78

I18 Hydrazines, voltammetric determinations, a 86 Hydride, measurements, in As, Sb, Se detection, a 142

concentration sensor I80 emission control from gas turbines 46 production, from syngas, a 31 unsaturated, hydrogenation, a 32, 144

Hydrwarboxylation, polybutadiene, styrene, a 146, 22 I

1-Hexane, hydroformylation, a 22 I

History, Pt metallurgy 80

Hot SpotTM Reactor, H generation

Hydrocarbons, aromatic, formation, a 144

S . American, Pt separation from Au


Page Hydrocracking, n-hexane, catalyst selectivity, a 143 Hydroformylation, 1 -hexme, by Ru(I11)-EDTA, a 9 I

alkenes, by Rh, compl es, a 32 ally1 alcohol, by KIRu (EDTA-H)CII.2H2O, a 90 by [Rh(CO),CIl I + phosphanorbornadienes, a 221 C,H,. on Rh catalysts, a 31. 90

90 propene, during D exchange reaction, a I43

213 catalytic reactions with CO, a 144, 219 charging in Pd. Pd-Au electrodes, a I40 chemisorbed on Pd/AI,OJ, for hydrogenations, a 89 chemisorption, on Ru-Cu/SiO, , a 31 coadsorption on Pt( I 1 I ) with HCI, a 213 concentration detection I80 detectors, a 28, 87, 214, 217 diffusion 17, 58, 137 diffusion electrodes, in fuel cell, a I47 effect on PdlLB filmlSi MIS devices, a 87 effects, in Pd films/SiO,/Si, optical transport, a 87 in MeOH synthesis, on PdlSiO, +MgO. Fe, a 89 in metals, Int. Symp. 17 in PdGe, PdSi, properties, a 82 isotopes, H, D, H-D. permeability, a 25 isotopic exchange, PTFElPtlsubstrate catalyst. a 30 oxidation, on sulphurised Pt, electrochemistry, a 139 Pd-Ce-H solid solutions, properties, a 82 permeation in Pd, C, S, effects on, a 2 I4

with D, through PdlFe 25 photoproduction, a 27. 85. 140, 141 production, by Hot SpotTM reactor 1 I8

from aqueous solutions, over Pt/TiO,, a 30 from EtOH, by Ru, Rh, complexes, a 145 from MeOH, in fuel cell, a 33 from PtIPAIC electrodes, a 84 from waste MeOH 58 in water gas shift reaction, a 90, 142 on IrO, cathodes, a 1 40

purification, by Pd-Ag 9, 58 220

reduction, on RuO, +La/ZrO,. a 31 removal from nuclear accidents, a 86 response, by microionic insertion sensor, a 87 separation, from N,. CO. by Pdlporous glass, a 87 solubility, in Pd-Rare Earth alloys, a 82, 214 uptake in Pd-Mg sandwiches, a 214

Hydrogen Chloride, a 29, 213 Hydrogen Sulphide, a 28. 85 Hydrogenation, I , 3-butadiene, a 29

acetone, a 30 alkynes, alkenes, a 89 a-keto esters, a 218 benzene, on Ru-PdlSiO, , synergism, a 90 CO, for Rh, RhFe zeolite structure, a 220

on Pt, Pd, Rh catalysts, a 31, 88. 142. 144, aldehydes, unsaturated HC. on PtlTiO, , a 90

CO,. on PdlLa20J, ISiO,, La-PdlSiO,, a 30 CzH2,C2H,, on H on PdlAI,O,, a 89 C,H,, by Pt(1I) ethyl complexes, a 22 1 dinitriles, on Rh/MgO. a 31 ethyl acetate, to EtOH, on Rh-SnlSiO,. a 220 graphite, by tunnelling catalysts, a 24 jojoba, castor oils, a 147 methyl oleate, a I45 olefins, a 25, 141, 220, 221 thiophene, by Pd-alizarin cly-Al,03, a 30 unsaturated hydrocarbons, a 32 vinylacetylene, a 30

Hydrogenolyses, a 143, 145 Hydroisomerisation, olefins, branched chain, a 144 Hydronium, ion, sensor, a 141

Inquartation, historical method of separating Pt 73 Iodides, organic. carbonylation, a I45 Ion Beam Bombardment, Pt( I 1 I ) surfaces, a 137

fir fluoro olefins, by Rh,(CO) 11, a

Hydrogen, adsorption in Pd, a

reaction with CO + benzyl halide, a

Page Iridium, density, crystallographic data 14

in SPE, for H I O electrolysis, a 139 35

Ir(1V) hydroxide, thermal change to IrO,, a 138 Ir-Ta buffer layer, in Y-Ba-Cu-0 thin films, a 92

Iridium Alloys, Iridium-Palladium, a 217 Iridium Complexes, carbenes, book review 1 I7

[IrCI(CO),LI, liquid crystals, a 83 Iridium Oxides, colloid, stabilised, a 28

electrochromic films, a 34, 223 in ORINEL electrodes, a 216 IrO, films, for electrodes, a 25

powder, formation, a I38 I r O ~ / A I ~ O J , resistors, a 35 110,. cathodes, evolution. a 140

35 Iron, qromoter, to PdlSiO, catalyst, a 89 Isomerisation, a 32, 88, 143, 144 Isooetane, cracking, catalyst intercrystalline effect, a 144 Isopropyl Alcohol, from acetone, on PtlTiO,, a 30 ITS-90, new temperature measurement scale I28

Johnson Matthey, HoneycatR industrial catalyst 178 Hot SpotTM Reactor H generation I I8 “Platinum 1989” 1 I3

Jojoba Oil, hydrogenation, by Ru complex, a 147

KELEX 100, for Pd extraction, a 147 Ketones, production, a 32, 147

P-Lactams, synthesis, a 148 Langmuir-Blodgett Films, in Pd/MIS devices, a 87 Lanthanum, a 30. 31, 218

20 for irradiating RhH(CO)(PPh,), catalyst. a 141, 221 for measuring luminescence decay, a 27 used in CVD of Pt, a 27

Lead, detection in food slurries 193 Lewis Acid, base titration. of Pd, Nb, a 84 Luminescence, in Ru, Pt complexes. a 27, 28, 85

Magnesium, a 89, 214 Magnetism, Dy I Ru Ip P I,, a I39

in PtlCo, Pd/Co films, for magneto-optics, a 222 PtMnSb films, a 223 Pt-Fe-B, a 24 Ru-Fe-Ga-Si, films, a 25

I77 in PtMnSb 54, 148 in PtlCo, Pd/Co ultrathin films, a 222

35, 92. 148, 223 anti-cancer drug therapies I62 detectors, a 216, 217

Membranes, catalysts, a 142, 219 Metallo-Ene, reactions in organic synthesis. a 145 Metallurgy, history 73. 80 Methane, a 31, 89, 214, 215, 222 Methanol, see Alcohols, methyl Methyl Oleate, hydrogenation, a 145 Methylcylopentane, conversion on Pt catalysts, a 29 Mineralogy, Geo-Platinum 87, conference report I3 Molybdenum, a 30, 139. 217 MOSFET, with Pd-Ir gate, for NHJ detection, a 217

Naphtha, reforming, a 29 Nickel, dissolving rates, a 26 Nickel Alloys, amorphous catal$p, in fuel cells, a 33 Nicotinamide, reduction. by Rh + Na fonnate. a 32 Nitric Acid, catalyst gauze studies, a 88. 218 Nltrobenzene, reduction, by Rh complexes, a 146 Nitrogen, implanted in PtTil, PdTilsteel, wear, a 81

27 90 89

Ir tin oxide, in optical attenuator, a

in an optical attenuator, a

Lasers, CO, TEA, PtlFecralloy catalyst in

Magneto-Optics, ColPt layers for storage media

Medical, a

N-0 bonds, deoxygenation. a 90

reaction with Pd. Mo/WO,/W, a photocatalytically fixed to NH J , a

to study C catalyst supports, a


Page Nitrogen Oxides, exhaust control, greenhouse effect 194

82 cycled reduction on automotive Pd catalyst, a144 effect on CO disruption of RhlAI,O,, a 31

81, 138 Nuclear Fuel, a 28. 86, 91 Nuclear Fusion, see Solid State Fusion 54 Nuclear Reactors, Pd coated steel 185 Nucleic Acid, reactions with Ru ion complexes, a 26 N-Acetyl-L-Cysteine, determination in water, a 2 17

Olefins, hydrogenations, a 25, 90, 141, 144, 220, 221 22 I

Organic Synthesis, using Pd complex catalysts 145. 186 Organostannanes, coupling with vinyl epoxides, a 146 Osmium, density, crystallographic data 14 Osmium Complexes, IosII(N-N)(L), I “ + ,

[Osl’(N-N),(L~(L’)lRe, preparation, properties, a 83 Osmium Tetroxlde 138, 181 Oxidation, alcohols, by Ru(1V)-0x0 phosphine. a 26

alkanes, by alkylhydroperoxides +Ru, a 32 ethers, by Ru(I1) complexes, a I47

benzyl alcohol, by Pt/poly[RuL, l’+-RuO,, a 27 butane, by Pt black-MO,, a 87 CO, a 137, 219, 220

33 ethylene, in PdCI,-CuCI, systems, a 146

PtlSiO sintering during, a 29 EtOH, on Pt electrodes, a 83 formaldehyde, for exhaust catalyst, a 88 H, on sulphurised Pt, electrochemistry. a I39 MeOH, at Mo-Pt-SPE electrodes, a 33, 139

26. 83, 84 91

methane, deep, on Pd/AI,O,, a 89 products of gas turbine engines 46 propane, propylene, on Pt, Pd, Rhla-AlzO,, a 142

222 propylene carbonate, on electrodes, a 215 Pt in catalysts, passivation. a 88 Rh. I ron SiO,, A1,Oj, microstructure. a 145 styrene, on Pd-Mn, a 30 thiophene, by Pd(I1) complexes, a 146

181 137

deactivation of PtlC, a 29 reduction, on fuel cell electrodes, a 33, 147

26, 83. 139 sensor, with SPE+Pt black electrode, a 216

Palladium, additives, effects on Ni-Cr catalysts, a 144 black, reactions with Pt chloro complexes, a 27 coating in furnace, for As, Sb, Se detection, a 142 coatings, of steel in nuclear reactors 185 complexes, compounds, for organic syntheses 186 compounds, Pd-Er, H solubility, a 214 electrode. catalytic behaviour, +Cd, TI, a 84 electroplating bath, a 86 extraction, by phase-transfer catalysis, a 147

91 films, in SiO,/Si, H effect, properties, a 87 gate layers, in microionic H insenion sensor, a 87 gate MOS transistor, a 28 Ge/Pd electrical contacts to n-AIGaAs, a 148 H permeation through, C, S effects on, a 214 hydride formation, from H, D adsorption, a 213

in electrodes. a 1 40 in PH 13-8 Mo stainless steel, structure, a 82 in sensors, a 87, 214, 217 modifier, to detect Pb, Sn, Cd in food slurries 193 Pd gates/LB filrn/Si MIS devices, a 87 Pd(l lo), D adsorption, phases, a 213 Pd(l 1 I ) , H diffusion. a I37

MeOH decomposition on, a 214 Pd(II), complexation with macrocyclic ligand, a 2 15

NO, adsorption on Rh(100). a

NO,, reduction by CO, on Pt foil, a

for aldehyde synthesis, a

CL-, in fuel cell, a

at Pt electrodes, a on Pt bimetalliclC in fuel cell, a

propylene. in phosphoric acid fuel cell, a

Oxidations, using OsO,, Ru oxides Oxygen, adsorption, on Pt( 110). a

on Pt electrodes, a

from spent nuclear fuel, a

Palladium (conrd. ) Page Pd-Fe-Zr, phase studies, a 25 Pd-Mg sandwiches, H uptake in, a 214 Pd-n-GaAs, contacts, a 92 Pd-Se system, superconductivity in, a 92

222 Pd/Fe, H-D permeation through, a 25 PdlInP(1 lo), Schottky barrier formation. a 92 Pdln-InP, MOS, barrier height, a 223 Pdlporous glass, for H separation, a 87 Pd’+lpoly(acrylic acid) film, for Cu plating, a 86 Pd,SilTa,NlAl, diffusion barrier, a 148 PdraTi,, films, implanted in stainless steel, a 81 powder production, for electronics 16 selective deposition on polyimide, by Ar laser. a 86 thin films, on Al surfaces, reactions, a 81 thin filmlglass, water gas shift reaction, a 87. 142 used in solid state fusion I I5 +hydroxylamine hydrochloride, for Mo, a 217

Palladium Alloys, Palladium-Cerium-Hydrogen, a 82 Palladium-Gold, electrodes, a 1 40

-Rhodium, short-range order in, a 24 Palladium-Iridium, for NH, sensor, a 217 Palladium-Nickel, electrodeposited, a 86

electrodes, a 215 membranes, for H, purification 9, 58

Palladium-Titanium, a 82, 84 Palladium-Yttrium, H solubility in, a 82 Pd-Rare Earth, H solubility,

thermodynamics, a 214 Pd-(B,P), thin films, olefin hydrogenation, a 25 Pd,,Ge,,,Pd.,,Si,,, H in, properties, a 82

Palladium Chlonde, PdCI, , MgCl, , complexes, a 26 to measure N-acetyl-L-cysteine in water, a 217

Palladium Complexes, in PdC12-MgCI, solution, a 26 organo-Pd, cationic, a 83 Pd(I1) carbenes, book review I I7

Palladium Hydride, formation, a 213 Palladium Silicides, a 214. 219 Paraffins, a 90 n-Pentane, reactions on Pt-XIAI,O,, a 29, 88 Permeability, H, D, through Pd, a 9. 25, 87, 142

see also Diffusion, Solubility Petroleum, for H production, Hot SpotTM reactor 118 Phase Changes, Pt-Si,Ge, --x thermal reactions, a 213

D, on Pd(llO), a 213 in HCI, H, H , O +Pt, a 213 in Pd, Pd-Au electrodes, a 1 40

Phase Diagrams, IrO,, a 25 Pd-Er, a 2 I4 Pd-Nb-0. a 84 Pd-Zr-Fe, a 25 Pt-AI, a 25 Rh-Nb-0, a 84 Ru-AI, a 25 Ru-Al-Ti. isothermal sections 106

Photocatalysis, a 27, 28, 85. 86. 140, 216 Photocurrent, in IRu(bpy),l’+/C,V2+, a 86 Plating, electroless, Cu, a 86

Pd on porous glass, for H separation, a 87 Pt electrolytes, a 28

I02 selective of Pd on polyimide by Ar laser, a I13

“Platinum 1989” 86 Platinum, additives, effects on Ni-Cr catalysts, a 144

amorphous phases with Al, a 24 anodes, corrosion in H,SO,, a 84

for MeOH oxidation, a 83 anti-cancer drugs I62 Bi,- ,Pb,Pt,-,RurOI -,. conductivity, a 223 black, electrode, in SPE 0 sensor, a 216 compounds, PtMnSb films, bulk, for

magneto-optics 54. 148 81

215

PdlCo ultrathin films, magneto-optics, a

Palladium-Silver, dental alloys, a 35

Pt. Pt alloys, new baths

Pt-Rh clusters, NMR study, a [NEt, 1 ,[Pt I ,(CO),,l, on graphite, a


Platinum (conrd.) Page Co/Pt layers, for magneto-optics 177, 222 crystallites, for 0 reduction, a 83 CVD, thin films, a 27 deposition of polyaniline, electrochemically, a I39 eletrodeposited, on graphite, STM studies, a 83 electrodes, as hydronium sensor, a 141

for cholinesterase, erythrocyte activity, a 216 for EtOH oxidation, a 83 for 0 reduction in saline, a I39 for propylene carbonate oxidation, a 215 in fuel cells, a 33. 147, 222 in sensors, a 141. 217 R(ll I ) , Pt(100) single crystals, a 84 h-Al surface alloy formation, a 84 PtIPAlC, H evolution, MeOH oxidation, a 84 WPt, WRh in thermoelectric converter 140 (100)-type, stabilisation in acid, a 84

foils, films, catalytic etching, a 24 gates in MOS gas detectors, a 28 grains, to stabilise n-GaAs photoanodes, a 2 16 HCHO-Pt-H,SO,, for hydrazine

determinations, a 86 heat probe, for circulating fluidised bed, a 216 in cermets, optical absorption, a 87 in electrodes, SPE, for H20 electrolysis, a 139 in low resistance electrical contacts, a 223 in spark plugs I05 microelectrodes, cylindrical, behaviour, a 2 16 on electrodes, in CO, sensor I27 particles deposition, on TiO, crystal surfaces, a 213 photodeposition, from hexachloroplatinate ion, a 27 plating 28, 102 powder production, for electronics 16 PtMnSb thin films, magnetic properties, a 223 Pt(ll0). CO, 0 adsorption, CO oxidation, a 137 Pt(l I I ) , deposition, characterisation, a I37

HCI, adsorption on, +H, +H,O, a 213 hydrogenation of I ,3-butadiene on, a 29

81 Pt(II), complexation with macrocyclic ligand, a 215 Pt(1V) species, on PtlRu electrodes, a 215 Pt-C stretch mode in Pt{ 1 1 I}-CO spectra, a 24 PtlCo ultrathin films, magneto-optics, a 177, 222 PtlGaAs, interfacial reactions, a I47 Ptl(l I I)Si, thickness effect on silicide, a 213 S adsorbed, H response, a I39 Schottky contacts, production, properties, a 223 sponge, reaction with alkali hydrides, a 26 substrates for ErBaCuO superconductors, a 34 Tennant, Wollaston, partnership, history 129 thermal reactions with Si,Ge,-,, a 213 thin coating on steel, slide wear 72 thin film deposition, for electrodes, a 28 used in solid state fusion 115

+SnO,/Si wafers, H sensing properties, a 217

Platinum-Aluminium, surface alloy on Pt 84

Platinum-Boron-Iron, magnetic properties, a 24 Platinum-Iron, martensitic transformation. in, a 8 I Platinum-Nickel, single crystals, a 24 Platinum-Rhodium, a 137, 142 Platinum-RhodiumlSiO,, heat treated, a I37 Pt50Ti50 films, implanted in stainless steel, a 81 UPt,-B, superconductor T, enhancement, a 91

Platinum Aluminide, coatings for gas turbine blades 127 Cr modified, coatings on superalloys, a 141

Platinum Chloride, PtCI,, a 26 35

S/Pt( 1 I I ) . CO adsorption on, a

wire wedge bonding, a 34

Platinum Alloys, plating baths I02

electrode in AI,Br, solution, a

Platinum Complexes, antitumour tests, a A,PtH,, structure, a 26 bis(Pt) with diammines, affinity for DNA, a 35 carbenes. book review 1 I7 cis-diammine Pt greens, one-pot synthesis, a 148 cis-diamminedichloro-Pt(I1). a I48

Platinum Complexes (conid.) Page cis-dichloroethylene-diamine-Pt(II), a 148

35 K,PtCI , reactions with Pd black, a 27 Pt ethyrenediamine single crystals, defect states, a 27 Pt(II), reaction with PtCl,, H,PtCI,, a 26

83 trans-lh(PMe,)CI,(NH,)l, in 0-cyclodextrin, a 25

1 I6 use in spark ignition engines, book review 105 with H, Int. Symp. 17

34, 91, 213, 223 28 91

142. 144 194, 212

88 from gas turbine engines 46 H burning after reactor accident, a 86 motor vehicle exhausts, greenhouse effects 143, 194 print industry drying gas 178 SAE Int. Congress, Detroit, 1989 61

139

144 Potassium, adsorption on Rh(100). a 82 Powders, 110,. Ir(1V) hydroxide thermolysis, a 138

Pt, Pd production 16 RulTiO,, for H photoproduction, a 141

Printing Industry, catalytic cleanup of gases 178 Promoters, CeO,, in three-way catalysts, a 143

30, 89 31 30 31 90

Propane, catalytic reactions, a 142, 145 Propene, exchange reaction with D, CO effect, a 143 Propylene, a 142, 222 Propylene Carbonate, a 215 Proton, detector, by Pd gate MIS Schottky diodes, a 87

K2PtCI,, binding to metallothioneins, a

sorption on ZrO, , a

Platinum Metals, conference announcement

Platinum Silicides, a Plutonium, analysis in nuclear fuel, a Poisoning, Pt catalyst, in fuel cell, a

self, in catalysts, by 0, HC, a Pollution Control, E.E.C. laws

catalysts in MeOH fuelled vehicles, a

Polyaniline, deposition, on Pt, a Polybutadiene, hydrocarboxylation, a 22 I Polymerisation, aldehydes, on Pd(III), a

Cr, in Pt-Rely-Al,O,, a 88 Fe, MgO, La, in PdlSiO, catalysts, a La,O ,, in Rh catalysts, a Mo, Re, W, in PtlX-zeolite catalysts, a Se, in Rh/ZrO, catalysts, a VOCI,.5HI0, in Rh/SiO, catalyst, a

Pumiliotoxin, synthesis, a 22 I

Redox, cycling, for catalyst characterisation, a 88 Reduction, bicarbonate, photocatalytically, a 141

Carbon oxides, on Rulpyrolysed polyacrylonitrile. a3 1

H,, on RuO,+La/ZrO,, a 31 Ir, Rh on A1,O1, microstructure, a I45 nitrobenzene, by Rh

complexeslSi0,. a 146 144

0, on Pt, a 26, 33, 83, 139, 147 21

Reforming, a 29, 143 Resistance Thermometers, Pt, use in new ITS-90

temperature scale 55, 128 Resistors, thick film, a 35, 92 Rhenium, promoter, in PtlX-zeolite catalyst, a 30 Rhodium, compounds, Pt-Rh clusters, NMR, a 81

215 in electrode, in AMTEC, a I40 in organic gas sensor, a I42 Rh(100), adsorption of K and NO, a 82 RhlTiO, system, for H sensor, a 217 thin film coatings, by plasma enhanced CVD 193

64 Rhodium-Gold-Palladium, short-range order, a 24 Rhodium-Niobium, thermodynamic stability, a 84 Rhodium-Platinum, (4 10) interactions, a 137 Rhodium-PlatinumlSiO, , microstructure, a 137 Rhodium-Titanium, thermodynamic stability, a 84

Rhodium Complexes, carbenes, book review 1 I7 Rh(phen),phi I+, DNA shape targeting, a 223

CO,, electrocatalytically 2

NO, cycled on Pd + La, 0 , la-Al 0 , , a Refining, platinum metals, in Gmelin

Rh,(CO),,, on graphite, structure, a

Rhodium Alloys, binary, mechanical properties

Rhodium Arsenide, a 34


Page Ruthenium, Bi2-~Pb,Ptl-,Rux0, a 223

Dy,Ru,,P,,, preparation, structure, a 139 Pb,Ru,O, +Ti oxide, in resistors, a 35 URu I Si , , compression, a 25

in fish freshness detector 23 isotopes, for spent nuclear fuel analysis, a 28

Ruthenium Alloys, Ruthenium-Aluminium, a 25 Ruthenium-Aluminium-Copper, a I38 Ruthenium-Gallium-Iron-Silicon, a 25

106 (Ti?,Ru,,),,Si I j , amorphous, corrosion, a 140

Ruthenium Complexes, bathophenanthroline-Ru(II), non-radioactive labels, for oligonucleotides, a 92

binding to DNA, a 92, 148 K,IRu(H,O)CI,l. spectroscopic properties, a 35 0x0. for oxidations 181 ruthenocenoylester, organ distribution, a I48 RuX,(DMSO), , synthesis, cancer activity. a 92 Ru(bpy) ’ +, luminescence, a 27, 85 Rul(CnHlnt ,),bpyl,, redox potentials, a 85 Ru” reactions with nucleic bases, a 26 IRu(bpy),I(BF,),lCH,CN. a 91 [Ruppy) 1 *+/C,V’+, photocurrents, a 86 IRu (H-EDTA)N,l-, a 216 [(bpy),Ru(b-b)Ru(biq),l‘+ , luminescence, a 28

Ruthenium Oxides, RuO,. thermodynamics, a 215 thick film resistors, a 35. 92 colloids, stabilised in polyelectrolyte, a 28

RuO,, Ru(VI1) ions, Ru(V1) ions, oxidants 181

compounds, Bi,Ru,O,, resistors, a 35

with Ti aluminides, structure, properties

Saccharides, detection, a 28 Schottky Barrier Devices, n-Si/Pd, Si/Ta,N/AI, a 148 Schottkv Barrier Transistors. PMOS. with PtSi. a 223 ~~. ~ ~~ ~ ~~~~~~

Ghottky Barriers, formation.. a 92 Schottky Contacts, Pt, F’tSi,, production. a 223 Schottky Diodes, proton detection, a 34. 87. 91 Selenium, a 31, 142 Semiconductors, MOS Pd gate, a 28

MOS Pt gate, as H,. NH, detectors. a 28 Pd films/SiO,/Si, a 87 Pd-MIS Schottky diodes, for proton detection, a 87 Pd/n-lnP, barrier height, a 223 PMOS, with PtSi, a 223 Si MISlLB filmslPd, a 87 SilSiO,. in H microionic insertion sens0r.a 87 +microheterojunctions, photocatalyst, a 85

Sensors, see Detectors Silicon, a 213, 214 Sintering, PtlSiO,, during C,H, oxidation, a 29 SMSI, a 30, 218 sodium, effect on Pd, Rh, Ru/SiO, . a 143 Solid State Fusion I14 Solubility, H, in metals 17, 82. 214

see also Diffusion, Permeability Solvent Extraction, reprocessing of Pd. a 91 Spark Plugs I05 Standard, frequency, using OsO, beam, a I38 Steam, effect on coking on Pt/AI 0 j , a I43 Steels, a 72, 81, 82. 185 Structure, I ,3-bridged 8-lactams. a I48

Al-Cu-Ru alloys. a I38 Dy,Ru,,P,,. a I39 Ir oxide films, a 25 micro, Rh, Ir particles on SO, . A1,Oj. a 145

137 81

PtlGaAs, during interfacial reactions, a I47 Ru-Ti aluminides 106 surface. Fe-Rhlgraphite catalyst particles, a 137

Styrene, a 30, 146. 221 Sulphides, ions, for H photoproduction, a 85 Sulphur, effect on H-Pd permeation, a 214

effects on Pt, a 81. 139, 143 Sulphuric Acid, corrosion of Pt anodes. a 84

Pt-Rh particles on SiO,, heat treated, a Pt-Fe alloys, martensite transformations. a

Page Superalloys, coated 127, 141 Superconductivity, a 34, 91, 92 Surface Science, Pt(l I I ) single crystals. a 137

Pt-Ni, a 24 Fe-Rhlgraphite catalyst particles, a I37 110, formation, structure, a 138 h-Rh(410) single crystals, interactions, a 137

90 Synthesis Gas, conversions, a 31, 32, 90, 91, 145

Tellurium, a 84, 143 Temperature Measurement, 0.01 -800K. by

Rh-Fe sensor 55 ITS-90 128

Tennant, Smithson, history 129 Thermodynamics, Pd-Rare Earth-H systems, a 214

RuO,. a 215

Synergism, in Ru-PdlSiO, catalysts, a

Thermomagneto-Optics, ColPt, for storage media Thick Films, cholinesterase activity, a

Thin Films, uRh,As on GaAs(001). growth, a

177 216

resistors, a 35, 92 34

Ir oxide, electrochromism, a 223 Pd. H, D adsorption in, a 213

81 Pd-(B,P) heat treated, olefin, hydrogenation, a 25 PdlCo, PtlCo, magneto-optics, a 177, 222 Pdlglass composite, water gas shift reaction, a 142 Pt, catalytic etching, a 24

in heat probe, a 216 produced by CVD, a 27 thermal reactions with Si,Ge,-,. a 213

PtMnSb 54. 223 PtSi. incoherent light annealed, a 91 PtTi, PdTi, on steel, wear, a 81 Pt-AI, amorphous phases, a 24 Pt-TiO,/glass, photocatalysts, a 85 Pt/( I 1 I)Si, silicide formation, a 213 Rh. deposition by plasma enhanced CVD I93

SnO,, +Pt/Si wafers, for H sensor, a 217 Y-Ba-Cu-0, with Ta-lr sandwich, a 92

Thiophnne, production, a 30 Thiophene, reactions, a 30, 146 Tin, detection in food slurries I93 Tin Oxide, a 214. 217 Titanium, TiO, crystal surfaces, Pt deposition, a 213 Titanium Alloys, Pd plated, a 82 Titanium Aluminides, alloy with Ru 106

Tungsten, a 30, 140 Tunnelling, of Pt, Ru. Ni, a 24

Uranium, URu,Si,, compression, a 25

Vinyl Carbamates, synthesis. a I47 Vinyl Epoxides, alkylations, a 146. 221 Vinylacetylene, hydrogenation, a 30 Vinylation, alkyl vinyl ethers. a 146 Vinylketones, dimerisation, by RhCI(PMe,), , a 221 Voltammetry, of hydrazines, a 86

on AI(I 1 I ) , Al(110). reactions, a

Rh-Fe temperature sensor 55

Toluene, irradiated carbony!ation. a 90

Wacker Process, catalyst for 60 Water, coadsorption on Pt( I 1 I ) with HCI; a 213

determination of N-acetyl-L-cysteine in. a 2 17 electrolysis, by Ir. Pt SPE. a 139 ML determination in. a 217 photolysis, with Pt-TiO, powders. a 1 40

Water Gas Shift Reaction, a 90. 142, 145 Wear, behaviour of Pt on steel 72

81 Wires, Pt. a 34. 142 Wollaston, William Hyde. history I29

Pt, Pd alloy films on stainless steels, a

m-Xylene, o-Xylene, isomerisation. a 144


contents · cis-[ptcl,(nh 3)2 1, and cis-tetrachloro- diammineplatinum(iv), cis-[ptcl,(nh,),i, as...

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