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VOLUME 53 NUMBER 4 OCTOBER 2009

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Platinum Metals Review is published by Johnson Matthey PLC, refiner and fabricator of the precious metals and sole marketing agent for the six platinumgroup metals produced by Anglo Platinum Limited, South Africa.

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Editor: David Jollie; Assistant Editor: Sara Coles; Editorial Assistant: Margery Ryan; Senior Information Scientist: Keith White

Platinum Metals Review, Johnson Matthey PLC, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K.E-mail: [email protected]

E-ISSN 1471–0676

PLATINUM METALS REVIEWA Quarterly Survey of Research on the Platinum Metals and

of Developments in their Application in Industrywww.platinummetalsreview.com

VOL. 53 OCTOBER 2009 NO. 4

ContentsPlatinum Metals Review Highlights PGM Research 182

An editorial by David Jollie

A Highly Active Palladium(I) Dimer 183for Pharmaceutical Applications

By Thomas J. Colacot

Precious Palladium-Aluminium-Based Alloys 189with High Hardness and Workability

By Julien Brelle, Andreas Blatter and René Ziegenhagen

The 23rd Santa Fe Symposium on Jewelry 198Manufacturing Technology

A conference review by Christopher W. Corti

Novel Chiral Chemistries Japan 2009 203A conference review by David J. Ager

Melting the Platinum Group Metals 209By W. P. Griffith

PGM Highlights: Ruthenium Complexes 216for Dye Sensitised Solar Cells

By M. Ryan

“PEM Fuel Cell Electrocatalysts and Catalyst Layers: 219Fundamentals and Applications”

A book review by Gregory J. Offer

The Taylor Conference 2009 221A conference review by S. E. Golunski and A. P. E. York

Abstracts 226

New Patents 228

Indexes to Volume 53 230

Platinum Metals Rev., 2009, 53, (4), 182 182

Welcome to the October 2009 issue ofPlatinum Metals Review.

In this issue, we introduce a new occasionalseries of “PGM Highlights”, in which we pre-sent selected examples of activity in an area ofcurrent interest in platinum group metal (pgm)research. Here, we have chosen the area of pho-toconversion, in which ruthenium-based dyesplay a significant role for dye sensitised solarcells. This mini-review by Margery Ryan, of thePMR Editorial Team, highlights some of theinnovative work in the recent patent literature. Itis an extension of the patent abstracts that weselect for each issue, and aims to provide morein-depth coverage of the chosen area togetherwith some background, referenced to the widerscientific literature, to set the scene.

Additionally, this issue includes as usual ourannual Subject and Name Indexes, to appear inNovember. The Name Index lists the names ofall authors, reviewers and conference speakerswhose work has appeared in Volume 53. TheSubject Index gives detailed, fully cross-refer-enced entries for all of the pgm-containingcatalysts, alloys, compounds and complexesmentioned in this Volume, together with theprincipal topics by keyword. It serves to demon-strate the richness of pgm research that we havereported throughout 2009 and we hope that youwill find it a useful reference.

If you have any comments please contactme on: [email protected].

DAVID JOLLIE, Editor

Platinum Metals Review Highlights PGMResearch

DOI: 10.1595/147106709X477160

IntroductionThe palladium(I) dimer, di-μ-bromobis(tri-tert-

butylphosphine)dipalladium(I), [Pd(μ-Br)( tBu3P)]2,was synthesised and fully characterised by Mingos(1, 2). However, its potential as a unique C–C andC–N coupling catalyst (3) was first explored byHartwig (6). It has emerged as one of the bestthird-generation coupling catalysts for cross-cou-pling reactions, including C–heteroatom couplingand α-arylations. In this review, the physical andchemical characteristics of the Pd(I) dimer as a cat-alyst material are discussed from a practicalviewpoint, and up to date information on its appli-cations in coupling catalysis is provided.

Characteristics and HandlingThe Pd(I) dimer is a dark greenish-blue

crystalline material, which gives a single peak in the31P NMR spectrum at (δ) 87.0 ppm. The 1H NMRspectrum gives a peak at (δ) 1.33 ppm (singlet; onexpansion it appears as a distorted triplet) in deuter-ated benzene (1, 2). The compound decomposes in

chlorinated solvents, especially in deuterated chlo-roform. The X-ray crystal structure is reported inthe literature as a dimer with Pd–Pd bonding, stabilised by bromine atoms via bridge formation(1, 2). It can be handled in air as a solid for a shortperiod of time, allowing the user to place it into areactor in the absence of a solvent, degas and thencarry out catalysis under inert conditions. However,this compound is highly sensitive to air and mois-ture in the solution phase. It can also decompose inthe solid phase if not stored under strictly inert conditions. The solid state decomposition patternover time was monitored in our laboratory at 0, 48and 112 hours (Figure 1) (4). Its sensitivity towardsoxygen is well understood, and is based on the formation of an oxygen-inserted product with theelimination of hydrogen (Scheme I) (5). Figure 2shows the oxygen sensitivity of the Pd(I) dimer ona proton-decoupled 31P NMR spectrum recordedusing a solvent which was not degassed. The peakat 107 ppm indicates the presence of the oxygen-inserted decomposition product.

183Platinum Metals Rev., 2009, 53, (4), 183–188

A Highly Active Palladium(I) Dimer forPharmaceutical Applications[Pd(µ-Br)(tBu3P)]2 AS A PRACTICAL CROSS-COUPLING CATALYST

By Thomas J. ColacotJohnson Matthey, Catalysis and Chiral Technologies, West Deptford, New Jersey 08066, U.S.A.; E-mail: [email protected]

The Pd(I) dimer [Pd(μ-Br)( tBu3P)]2 is one of the best third-generation cross-coupling catalystsfor carbon–carbon and carbon–heteroatom coupling reactions. Information on itscharacterisation and handling are presented, including its decomposition mechanism in thepresence of oxygen. The catalytic activity of [Pd(μ-Br)( tBu3P)]2 is higher than either( tBu3P)Pd(0) or the in situ generated catalyst system based on Pd2(dba)3 with tBu3P. Examplesof suitable reactions for which the Pd(I) dimer offers superior performance are given.

DOI: 10.1595/147106709X472147

0 h 48 h 112 h

Fig. 1 The solid stateoxygen sensitivity of purePd(I) dimer, [Pd(μ-Br)( tBu3P)]2, withtime (4)

Applications in Coupling CatalysisThe high catalytic activity of the Pd(I) dimer

[Pd(μ-Br)(tBu3P)]2 is due to its ease of activation,presumably to a highly active, coordinatively unsat-urated and kinetically favoured ‘12-electron’catalyst species, (tBu3P)Pd(0) (Scheme II). Thisrenders the Pd(I) dimer more active than either theknown ‘14-electron Pd(0)’ catalyst, (tBu3P)2Pd(0),or the Pd(0) catalyst generated in situ by mixingPd2(dba)3 with two molar equivalents of tBu3P. Theapplications of the Pd(I) dimer in organic synthesisare described below.

Carbon–Heteroatom CouplingHartwig identified the potential of the Pd(I)

dimer as a highly active catalyst for C–N coupling

using aryl chlorides as substrates with variousamines at room temperature. A few examples areshown in Scheme III (6). Typically, aryl chloridecoupling requires higher temperatures and longerreaction times when using the in situ generatedPd(0) catalyst, or even the (tBu3P)2Pd(0) complex(7). Around the same time, Prashad and cowork-ers at Novartis reported an amination reactionusing [Pd(μ-Br)(tBu3P)]2 with challenging sub-strates such as hindered anilines (8). Scheme IVshows the coupling of N-cyclohexylaniline withbromobenzene, comparing the performance ofthe Pd(I) dimer with those of in situ generated cat-alysts derived from Pd(OAc)2 with tBu3P, BINAP,Xantphos or DPEphos. The performance of[Pd(μ-Br)(tBu3P)]2 is superior in each case.

Platinum Metals Rev., 2009, 53, (4) 184

180 140160 120 100 80 60 40 20 0 ppm

Fig. 2 The oxygensensitivity of Pd(I)dimer, [Pd(μ-Br)( tBu3P)]2, as observed in the 31P NMR (ppm)spectrum recordedusing non-degassedC6D6

P P

B r

P d

B r

P d O 2

- 2 H

O

P d

O

P d

C H 2

C H 2

P

B r P

B r

3 1 P N M R : 8 7 P P M 3 1 P N M R : 1 0 7 P P M

P d ( I ) d i m e r 31

P NMR: 107 ppm

–2H

P P

Br

Pd

Br

Pd P Pd

Highly active 12-electron species

Scheme I Theoxygen sensitivityof Pd(I) dimer,[Pd(μ-Br)( tBu3P)]2,with the formationof an inactive Pd-Ospecies (5)

Scheme II The activationof Pd(I) dimer to a 12-electron catalystspecies during couplingcatalysis

Pd(I) dimer

31P NMR: 87 ppm

Hartwig’s group subsequently conducted adetailed study to understand the activity and scopeof [Pd(μ-Br)(tBu3P)]2 in the amination of five-membered heterocyclic halides. Variouscombinations of Pd precursors with tBu3P werestudied for a model system, the reaction of N-methylaniline with 3-bromothiophene. Thefastest reaction occurred with the Pd(I) dimer (9).

More recently, Eichman and Stambuli reporteda very interesting zinc-mediated Pd(I) dimer-catalysed C–S coupling, which should generatemuch interest in the area of C–S coupling(Scheme V) (10). For the reactions of alkyl thiolswith aryl bromides and iodides, potassium hydridewas the best base, as illustrated in Scheme V. Forthe Pd-catalysed cross-coupling reactions of aryl

bromides and benzenethiol using zinc chloride incatalytic amounts, with sodium tert-butoxide asthe base, most of the reactions were sluggish andgave low yields. However, the addition of stoi-chiometric amounts of lithium iodide increasedthe rate of the reaction significantly, which isspeculated to be due to the anionic effects pro-posed by Amatore and Jutand (11).

Carbon–Carbon Bond FormationHartwig’s group also studied the Suzuki cou-

pling of sterically hindered tri-substituted arylbromides. A Pd(I) dimer loading of 0.5 mol%, inthe presence of alkali metal hydroxide base, gavegood yields at room temperature within minutes(Scheme VI) (6).


0.5 mol% Pd(I) dimer

NaOtBu, RT

15 min–1 h

R = Bu, Ph

or R2NH = morpholine

R

Yield 88–99%

Cl

R

R

NH +

R

N

Scheme III Arylchloride coupling atroom temperature (6)

Pd catalysts

NaOtBu, Toluene, 110°C

Catalyst loading Yield

[Pd(μ-Br)(tBu3P)]2 0.25 mol% 93%

Pd(OAc)2 + tBu3P 0.5 mol% 86%

Pd(OAc)2 + BINAP 0.5 mol% 27%

Pd(OAc)2 + Xantphos 0.5 mol% 27%

Pd(OAc)2 + DPEphos 0.5 mol% none

Br

+

HN N

Scheme IV Pd(I) dimer-catalysed C–N coupling of N-cyclohexylaniline (8)

0.5–2.0 mol% Pd(I) dimer

THF

ZnCl2 (catalyst)

KH (1.1 equiv.)

X = Br, I

Ar-X + RSH Ar-S-R

Yield 46–99%

R = tBu,

nBu, PhCH2

Scheme V Zinc-mediatedPd(I) dimer-catalysed C–Scoupling (10)

Research work from Ryberg at Astra Zeneca(12) demonstrated a very practical, clean methodfor C–CN coupling using the Pd(I) dimer [Pd(μ-Br)(tBu3P)]2 to produce 3 kg to 7 kg ofproduct routinely (Scheme VII). During the initialin situ studies, Pd2(dba)3 in combination withcommercial ligands such as Q-Phos, tBu2P-biphenyl or Cy2P-biphenyl gave poor results,although with proper process tweaking improve-ments were made. The conventional ligands, suchas Ph3P and dppf, were not useful. However, theP(o-tol)3/Pd2(dba)3 system behaved somewhatwell with the formation of some byproducts. The

Pd loading was as high as 5 mol% (12).For the α-arylation (13) of fairly challenging

carbonyl compounds, Hartwig identified thePd(I) dimer [Pd(μ-Br)(tBu3P)]2 as one of the bestcatalysts, especially for amides and esters. Thework from Hartwig’s group provided generalconditions for α-arylations of esters and amides(14–16). The coupling reactions of aryl halideswith esters are summarised in Scheme VIII (17).For aryl bromides, lithium dicyclohexylamide(LiNCy2) was the best base, while sodium hexa-methyldisilazide (NaHMDS) was required for arylchloride substrates. Intermolecular α-arylation of


Yield 84–95%

0.5 mol% Pd(I) dimer

KOH, THF

15 min, RT

Ph

R1R

2

R3

PhB(OH)2

X

R1R

2

R3

+

Scheme VI Roomtemperature Suzukicoupling of stericallybulky aryl bromides (6)

Pd(I) dimer, Zn(CN)2

Zn, DMF

50ºC, 1–3 hN

HN

Br

OH

N

O

N

HN

NC

OH

N

O

Yield 71–88%R

1, R

2= Me, H; R = Me,

tBu

X = Br, Cl; R3

= Me, MeO, F

(i) LiNCy2 (X = Br) or

NaHMDS (X = Cl)

Toluene, RT, 10 min

(ii) Pd(I) dimer

RT–100ºC, 4 h

R2

R1

R3

O

OR

+

X

R3

O

R1

OR

R2

Scheme VIII α-Arylation of esters under milder conditions using the Pd(I) dimer catalyst (17)

Scheme VIIThe Pd(I)dimer-catalysedcyanationreaction, whichmay be carriedout on akilogram scale(12)

X = Br;

R1

= H, CN, CF3, OCH3 or CH3; R2, R

3= H or CH3

in situ generated zinc enolates of amides was alsoreported in excellent yield under Reformatskyconditions using the Pd(I) dimer, (Scheme IX)(18). The appropriate choice of base for the sub-strate is critical for this reaction.

The α-vinylation of carbonyl compounds hasbeen reported recently by Huang and coworkersat Amgen, catalysed by the Pd(I) dimer in con-junction with lithium hexamethyldisilazide(LiHMDS) base (Scheme X) (19). The same cat-alytic system can be extended to the α-vinylation

of ketones and esters. The combination ofPd2(dba)3 with Buchwald ligands such as X-Phosand S-Phos gave inferior results, as did in situcatalysis with ligands such as Xantphos, (S)-MOP,BINAP and IPr-HCl (carbene) in the presence ofPd2(dba)3. Amgen researchers also reported astereoselective α-arylation of 4-substituted cyclo-hexyl esters using the Pd(I) dimer at roomtemperature, with lithium diisopropylamide(LDA) as the base. Diastereomeric ratios, dr, ofup to 37:1 were achieved (Scheme XI) (20).


Glossary

Ligand Full name

BINAP 2,2' -bis(diphenylphosphino)-1,1' -binaphthyltBu2P-biphenyl 2-(di-tert-butylphosphino)biphenyltBu3 tri-tert-butylphosphine

Cy2P-biphenyl 2-(dicyclohexylphosphino)biphenyl

dba dibenzylideneacetone

DPEphos bis(2-diphenylphosphinophenyl)ether

dppf 1,1' -bis(diphenylphosphino)ferrocene

IPr-HCl (carbene) 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride

(S)-MOP 2-(diphenylphosphino)-2' -methoxy-1,1' -binaphthyl

OAc acetate

P(o-tol)3 tri(o-tolyl)phosphine

Ph3P triphenylphosphine

Q-Phos 1,2,3,4,5-pentaphenyl-1' -(di-tert-butylphosphino)ferrocene

S-Phos 2-dicyclohexylphosphanyl-2' ,6' -dimethoxybiphenyl

Xantphos 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene

X-Phos 2-dicyclohexylphosphino-2' ,4' ,6' -triisopropylbiphenyl

(i) 1.5 equiv. Zn*

THF, RT, 30 min

(ii) 2.5 mol% Pd(I) dimer

Yield

94%

O

X

NMe2

Br

N

O

NMe2

N

Yield 48–95%

Toluene, 80ºC, 24 h

Pd(I) dimer, LiHMDS

X = Br, OTf, OTs

R1

R3

X

R2

R'''R''R'

OR

1

R2

R3

R'''

R''R'

O

+

Scheme IX α-Arylation ofamides underReformatskyconditions (18);Zn* = activatedzinc species

Scheme X α-Vinylationreaction usingPd(I) dimercatalyst (19);OTf =trifluoromethanesulfonate; OTs = tosylate

ConclusionsThe Pd(I) dimer [Pd(μ-Br)(tBu3P)]2 stands out

as unique among the third generation catalysts forcross-coupling. It has a higher activity than othercatalysts, a fact which can be attributed to its abili-ty to form a 12-electron ‘ligand-Pd(0)’ speciesduring the activation step in the catalytic cycle. Itsapplication to a wide variety of C–C, C–N and C–S

cross-coupling reactions will enable higher yieldsand better product selectivities under relativelymild conditions.

AcknowledgementsFred Hancock and Gerard Compagnoni of

Johnson Matthey’s Catalysis and Chiral Technologiesare acknowledged for their support of this work.


The AuthorDr Thomas J. Colacot is a Research and DevelopmentManager in Homogeneous Catalysis (Global) ofJohnson Matthey’s Catalysis and Chiral Technologiesbusiness unit. Since 2003 his responsibilities includedeveloping and managing a new catalyst developmentprogramme, catalytic organic chemistry processes,scale up, customer presentations and technologytransfers of processes globally.

1 R. Vilar, D. M. P. Mingos and C. J. Cardin, J. Chem.Soc., Dalton Trans., 1996, (23), 4313

2 V. Durà-Vilà, D. M. P. Mingos, R. Vilar, A. J. P. Whiteand D. J. Williams, J. Organomet. Chem., 2000, 600, (1–2),198

3 T. J. Colacot, ‘Di-μ-bromobis(tri-tert-butylphos-phine)dipalladium(I)’, to be included in 2009 in“e-EROS Encyclopedia of Reagents for OrganicSynthesis” , eds. L. A. Paquette, D. Crich, P. L.Fuchs and G. Molander, John Wiley & Sons Ltd.,published online at: www.mrw.interscience.wiley.com/eros (Accessed on 30th July 2009)

4 Johnson Matthey Catalysts, ‘Coupling CatalysisApplication Table’, West Deptford, New Jersey, U.S.A.:http://www.jmcatalysts.com/pharma/pdfs-uploaded/Coupling%20%20Apps%20Table.pdf(Accessed on 30th July 2009)

5 V. Durà-Vilà, D. M. P. Mingos, R. Vilar, A. J. P. Whiteand D. J. Williams, Chem. Commun., 2000, (16), 1525

6 J. P. Stambuli, R. Kuwano and J. F. Hartwig, Angew.Chem. Int. Ed., 2002, 41, (24), 4746

7 R. Kuwano, M. Utsunomiya and J. F. Hartwig, J. Org.Chem., 2002, 67, (18), 6479

8 M. Prashad, X. Y. Mak, Y. Liu and O. Repic, J. Org.Chem., 2003, 68, (3), 1163

9 M. W. Hooper, M. Utsunomiya and J. F. Hartwig, J.Org. Chem., 2003, 68, (7), 2861

10 C. C. Eichman and J. P. Stambuli, J. Org. Chem., 2009,74, (10), 4005

11 C. Amatore and A. Jutand, Acc. Chem. Res., 2000, 33,(5), 314

12 P. Ryberg, Org. Process Res. Dev., 2008, 12, (3), 54013 C. C. C. Johansson and T. J. Colacot, Angew. Chem.,

2009, in press14 T. Hama and J. F. Hartwig, Org. Lett., 2008, 10, (8),

154915 T. Hama and J. F. Hartwig, Org. Lett., 2008, 10, (8),

154516 T. Hama, X. Liu, D. A. Culkin and J. F. Hartwig, J.

Am. Chem. Soc., 2003, 125, (37), 1117617 T. Hama and J. F. Hartwig, Synfacts, 2008, (7), 075018 T. Hama, D. A. Culkin and J. F. Hartwig, J. Am. Chem.

Soc., 2006, 128, (15), 497619 J. Huang, E. Bunel and M. M. Faul, Org. Lett., 2007,

9, (21), 434320 E. A. Bercot, S. Caille, T. M. Bostick, K. Ranganathan,

R. Jensen and M. F. Faul, Org. Lett., 2008, 10, (22),5251

Pd(I) dimer, LDA

Toluene, RT, 3–24 h

Yield 37–85%

Up to 37:1 dr

R1 R

1

CO2Et

R–X+

CO2Et

R

Scheme XI Roomtemperaturediasteroselectiveα-arylation of 4-substitutedcyclohexyl estersusing Pd(I) dimer(20)

References

Palladium is not widely recognised as a preciousmetal in jewellery and watchmaking. Yet, with theprice evolution of precious metals over the lastfew years, use of palladium in these markets hasseen renewed interest (1–3). For illustration, goldwas roughly double the price of palladium in 2006and about four times the price of palladium at theend of 2008 (4). In addition, palladium alloys forjewellery, which usually contain 95 wt.% Pd (950Pd), have a lower density (around 12 g cm–3) than18 carat white gold (close to 15 g cm–3) and 950platinum (about 21 g cm–3). Hence, an item of vol-ume 1 cm3 in 950 Pd contains 11.4 g Pd. Bycomparison, the same item made in 18 carat whitegold (750 Au) or 950 Pt will contain, respectively,11.3 g Au or 20 g Pt.

Furthermore, the 950 Pd alloys approach the‘ideal’ white colour of platinum without requiringrhodium plating like most white gold alloys. Unlikefor gold alloys, the white sheen will therefore notwear off, eliminating the bother and expense of re-plating. 950 Pd alloys also satisfy the generalrequirements for jewellery and watch alloys: they

are nickel-free, malleable, easy to polish, and havedesirable setting and forming characteristics. Theirhigh Pd content also confers good corrosion andtarnishing resistance, a crucial aspect in jewelleryand watchmaking.

The inherently low hardness of Pd alloys is,however, an important technical limitation fortheir use in jewellery and particularly in watchmak-ing. The hardness of existing 950 Pd alloys, withalloying metals such as ruthenium (PdRu), gallium(PdGa) or copper (PdCu), falls between 70 HV(PdCu) and 120 HV (PdGa) in the annealed state,and between 145 HV (PdCu) and 200 HV (PdGa)after 75% strain hardening. These values are sub-stantially lower than those typical of platinum orwhite gold alloys (≥ 130 HV annealed, ≥ 250 HVwork hardened).

In an attempt to develop a 950 Pd single-phasealloy with substantially higher hardness, compara-ble with platinum and white gold, whilemaintaining the favourable colour and workabilityof conventional Pd alloys, we investigated PdAl-based compositions, in particular the PdAlRu


Precious Palladium-Aluminium-BasedAlloys with High Hardness and Workability PROMISING POTENTIAL FOR APPLICATION IN JEWELLERY AND WATCHMAKING

By Julien Brelle and Andreas Blatter*PX Holding SA, R&D, Boulevard des Eplatures 42, CH-2300 La Chaux-de-Fonds, Switzerland;

*E-mail: [email protected]

and René ZiegenhagenCartier Horlogerie, Branch of Richemont International SA, 10 Chemin des Aliziers, CH-2300 La Chaux-de-Fonds, Switzerland

New palladium-aluminium-based alloys with promising potential for application in the areasof jewellery and watchmaking are presented. A particular emphasis is placed on the mechanicalbehaviour of ternary palladium-aluminium-ruthenium (PdAlRu) alloys with 95 wt.% Pd.The new alloys combine high plasticity with high hardness relative to common Pd alloys.The low work-hardening rate enables cold working in excess of 95% reduction withoutintermediate annealing. The hardness (Vickers pyramid indentation) ranges from 100 HV to300 HV in the annealed condition, depending on the Al:Ru ratio. Their whiteness in terms ofcolour coordinates is compared with platinum and white gold. The feasibility of porcelainfusion to PdAlRu for decorative purposes is also demonstrated.

DOI: 10.1595/147106709X472192

system. This paper describes the background tothe alloy development, presents the main charac-teristics of 950 PdAlRu alloys in terms ofmechanical properties and workability, andaddresses the possibility of fusing coloured ceram-ic material to the alloy for decorative purposes.

Background to the Development ofthe PdAlRu Alloys

While precipitation hardening may also be ofinterest to further increase the rigidity and wearresistance of finished components, solid solutionstrengthening is the mechanism that must providethe base hardness of the alloy in the annealed state.

Solid solution strengthening is the result ofstrain produced in the crystal lattice, mainly by thesize misfit between matrix and solute atoms. Sincesize misfit also limits the terminal solid solubility,as described by the Hume-Rothery rules (5), itmust be kept within certain limits to ensure a solu-bility of at least 5 wt.%, which is necessary for a950 Pd single-phase alloy. For a given solute, thestrength increases with its atomic fraction (at.%).Higher atomic fractions are achieved when alloy-ing with light elements. In 950 Pd, for illustration,5 wt.% aluminium corresponds to 17.2 at.%. A 950Pd alloy may include several alloy additions, whichmust be fully soluble and must add up to a total of5 wt.%.

The effects of a great number of solute ele-ments on the hardness of palladium have beencompiled previously (6, 7). Germanium, silicon andboron have a strong hardening effect. However, Bis difficult to alloy and Ge and Si both exhibit near-ly zero solubility. As a result, when added insufficient concentrations to give a hardness above150 HV, these elements tend to precipitate at thegrain boundaries and thereby render the alloy toobrittle for practical use. For those elements whichare more practical in terms of alloying, such asother precious metals or 3d transition metals, thehardness values attained at concentrations of 5wt.% barely exceed 100 HV. Ru is one of the ele-ments showing the most pronounced effect on thehardness of Pd alloys. Hardness values in the range150 HV to 200 HV can be achieved with rare earthmetals such as cerium (8).

With respect to the light elements, 5 wt.% tita-nium raises the hardness to 150 HV (9), while Alboosts the value to 320 HV (440 HV after 80%cold work), according to our own experiments.While a hardness of 150 HV is at the lower edgeof the target range, a value of 320 HV may beinconveniently high for many conventional jew-ellery manufacturing operations such as stampingor setting.

The present study therefore focused on PdAl-based alloys, incorporating ternary additions of Ru,Ti and magnesium in order to moderate the hard-ness. Ru was chosen because it is a noble metal, agood solution hardener, and commonly used in 950Pd alloys. Ti and Mg were chosen because they arelightweight, good solution hardeners, and may pos-sibly provide a mechanism of precipitationhardening by the formation of tiny AlTi or AlMgcompounds upon ageing – in similarity with super-alloys. Table I shows the hardness values obtainedfor various ternary alloys in the annealed and 80%work hardened conditions, respectively. This showsthat the hardness values in the annealed state lie inthe target range and that cold work generates sub-stantial hardening. The values displayed are thosefor ‘low’ and ‘high’ concentrations of the ternaryadditions; intermediate concentrations gave inter-mediate values for hardness. All alloys were singlephase and sufficiently malleable for a rolling reduc-tion of 80% without cracking. It is interesting tonote that there have been two independent patentapplications for 950 PdAl-based alloys (10, 11).


Table I

Vickers Hardness Values of Various PdAl-(Ti, Mg,Ru) Alloys in the Annealed and 80% ReductionWork-Hardened States*

Alloy Hardness, HV

Annealed Work-hardened

Pd95.5Al1.3Ti3.2 154 366Pd95.5Al0.4Ti4.1 128 338Pd95.5Al3.8Mg0.7 242 400Pd95.5Al1.9Mg2.6 170 340Pd95.5Al2.8Ru1.7 224 343Pd95.5Al0.9Ru3.6 158 247

* The standard deviations associated with the displayed meanvalues are below ± 7 HV

The advantage of Ru as the ternary element isthat unlike Mg or Ti, it does not cause a violentreaction with Al upon alloying. In this paper, wefocus on our development work on the 950PdAlRu system.

PropertiesTwo alloys of nominal composition (in wt.%)

Pd95.5Al0.9Ru3.6 and Pd95.5Al2.8Ru1.7 were prepared ina vacuum induction melting unit. The unit cham-ber was evacuated and purged with argon severaltimes before backfilling with argon to 600 mbar.The elemental metals were melted in a zirconiacrucible. The Al flakes were wrapped in Pd sheetsto avoid any reaction with the crucible and also toalloy the Al with the higher melting point Pdwithout significant expulsion of Al. Plate-likeingots of 5 kg each were cast into an oxidised copper mould to constitute the feedstock for thevarious tests. After a first flat rolling, rods werecut off the plate and further rolled to adequatesize for tensile testing while the rest of the platewas used for workability tests and microstructuralinvestigations.

The X-ray diffraction pattern in Figure 1reveals that the ternary alloys are essentially singlephase, face centred cubic (f.c.c.) solid solutions. InRu-rich alloys, a new diffraction peak appears, andits intensity increases with increasing Ru content.Additional peaks, too weak to be seen in Figure 1,become visible when zooming into the data. Thesepeaks, located at scattering angles, 2θ, of 44.0º,

58.3º, 78.2º, 84.8º, and 104.8º, respectively, areclose to those of pure Ru and enable the secondphase to be assigned to a Ru-rich PdRu hexagonalclose packed (h.c.p.) solid solution.

The measured lattice constants, a, of theternary f.c.c. matrix are accurately reproduced witha hard sphere approximation by the linear combi-nation of the atomic sizes, Sj, defined as theminimum interatomic distance in the unit cell ofelement j (Equation (i)):

(i)

where the coefficients cj correspond to the atomicfraction of element j.

The atomic sizes for Pd, Al and Ru are, respec-tively, 2.750 nm, 2.863 nm and 2.650 nm (12).Since Al has a greater atomic size than Pd by4.1%, whereas Ru is smaller by 2.6%, the apparentshift in a is marginal among different ternaryalloys. In other words, strengthening due to latticedistortion is not apparent through a significantshift of the diffraction peaks. In particular, thereexists a ternary composition for which the latticeconstant almost matches that of elemental Pd.The lattice constant derived from the diffractionpattern of Pd95.5Al0.9Ru3.6 is 3.888 nm, compared to3.886 nm for Pd.

Hardness The hardness of the PdAlRu alloys in the

annealed state (1000ºC for one hour), measuredusing a Vickers hardness tester with a 1 kg load


∑⋅=j

jjSca 2

Pd95.5Al0.9Ru3.6

Scattering angle, 2θ

0 20 40 60 80 100 120

Inte

nsity, a.u

.

Fig. 1 X-Ray diffraction patterns ofannealed Pd95.5Al0.9Ru3.6. A θ–2θconfiguration and Cu Kα1 radiation(α = 0.15408 nm) were employed.The sample is predominantly f.c.c.single phase. An additional peak at2θ ≈ 42 indicates the presence of asecond phase

×

(HV1), approximates to a linear function of the Alcontent, as shown in Figure 2. Therefore, thehardness can be tuned to any value from about100 HV (PdRu) to 320 HV (PdAl). The hardnessvalues in the work-hardened condition range from165 HV (PdRu) to 440 HV (PdAl). Correspondingvalues for two ternary compositions are given inTable I. Upon ageing of annealed samples at700ºC for twenty minutes, the hardness of thosealloys with higher Ru content increases slightly,indicating a mechanism of precipitation harden-ing. The intensity of age hardening remainsmodest, however: it approaches but does notexceed the increase of 25 HV observed at thehighest Ru content, i.e. for the binary 950 PdRualloy. This strengthening is also evident in an

increase in yield strength of 50 MPa forPd95.5Al0.9Ru3.6 (Figure 3).

Age hardening is accompanied by a substantialincrease in electrical resistivity, ρel, as measured bymeans of the four-point probe technique on discsof thickness 2 mm and diameter 27 mm (13). ForPd95.5Al0.9Ru3.6, ρel reversibly switches from25.5 μΩ cm in the annealed state to 91 μΩ cm inthe age hardened state. By comparison, the valuesfor Pd95.5Al2.8Ru1.7, which does not exhibit agehardening, are 32.1 μΩ cm and 35.6 μΩ cm,respectively. Since an increase in electrical resistiv-ity is caused by additional scattering of electrons atcrystal imperfections, such as a lattice distortion orthe presence of precipitates, and since age harden-ing occurs with the appearance of a PdRu phase as


R2

= 0.9911

Aluminium, wt.%

01 2 3 4 5 6

50

100

150

200

250

300

350V

ickers

hard

ness, H

V1

y = 42.523x + 109

Fig. 2 Variation of Vickers hardnessvalues, HV1, with Al content x (wt.%)of annealed Pd95AlxRu(5 – x) alloys. Thelinear approximation is shown

Pd95.5Al2.8Ru1.7

Pd95.5Al0.9Ru3.6

Engineering strain, %

Engin

eering s

tress, M

Pa

5 10 15 20 25 30 350

200

400

600

800

1000

1200

CW

AH

AH

AN

AN

Fig. 3 Typicalengineering stress-strain curves recordedfor Pd95.5Al2.8Ru1.7 andPd95.5Al0.9Ru3.6 in theannealed (AN), age-hardened (AH) and85% cold-worked(CW) states

discussed above, it is tempting to correlate agehardening with PdRu precipitates. However, themain diffraction peak of the PdRu phase persistsupon annealing, suggesting that the precipitatesare not fully solubilised.

Figure 4 shows the variation of conventionalyield strength, Rp0.2, ultimate tensile strength, Rm,and fracture strain, A50, with cold work. The alloysundergo significant strain hardening only upon initial cold working. Beyond about 30% of coldwork, yield strengths (Figure 4) and hardness values (Figure 5) remain essentially constant. It isworth mentioning that the tensile properties of theRu-rich alloy after standard annealing (1000ºC for1 hour) depend on its thermomechanical history.

This is no longer the case after cold working. Weattribute this memory behaviour to a variable evo-lution and dissolution of the PdRu precipitates.

The work hardening exponent, n, can be rough-ly estimated from a fit of the Hollomon equation(Equation (ii)) to the true stress-true strain curve(14):

σt = Kεtn (ii)

Here, K, the strength index, is a constant and thetrue stress-true strain data (σt, εt) is obtained fromthe engineering data (σ, ε) by Equations (iii) and (iv):

σt = σ(1 + ε) (iii)

εt = ln(1 + ε) (iv)


Cold work, %

Rm

/Rp

0.2, M

pa

20 40 60 80 1000

200

400

600

800

1000

1200

7

14

21

28

35

42

A50 , %

Pd95.5Al0.9Ru3.6

Pd95.5Al2.8Ru1.7

A50

Rm

Rm

Rp0.2

Rp0.2

0

Pd95.5Al2.8Ru1.7

Pd95.5Al0.9Ru3.6

Cold work, %

Vic

kers

hard

ness, H

V1

350

300

250

200

150

100

50

0 20 40 60 80 100

Fig. 5 Variation of Vickers hardness,HV1, with cold work. Each data pointis the average of five tests (standarddeviation < 5%)

Fig. 4 Yieldstrengths, Rp0.2,ultimate tensilestrengths, Rm, andfracture strains, A50,as derived fromstandard tensiletesting (EN 10002-1:1990) of two PdAlRualloys at variousdegrees of cold work.Each data point is theaverage of five tests(standard deviation < 3% except for A50).Connecting linesserve as a guide tothe eye

where σt is the true stress, σ is the engineeringstress, εt is the true strain and ε is the engineeringstrain.

When applied to the stress-strain curves ofannealed samples in the plastic domain (Figure 3),this approximation returns n = 0.29 forPd95.5Al2.8Ru1.7 and n = 0.25 for Pd95.5Al0.9Ru3.6, val-ues that are typical of low stacking-fault energyalloys such as Al alloys.

Figure 6 depicts the mechanical properties ofPdAlRu alloys in comparison with those of com-mon Pd, Pt or Au alloys. The ternary 950 PdAlRualloys exhibit higher strength and hardness thanconventional 950 PdRu, but lower fracture strains.Tensile strengths and hardness values are similar tothose of Pt or Au alloys. Fracture strains are com-parable or somewhat lower in the annealed state,whereas they are higher after 75% cold work. Yieldstrengths may be somewhat lower or higher in theannealed condition, depending on the Al content.

After cold working, however, the yield strengths ofthe PdAlRu alloys remain largely below those ofthe Pt or Au alloys – another clear manifestation ofthe low work-hardening rate, i.e. the high plasticity,of these ternary alloys.

Young’s modulus, E, and Poisson’s ratio, ν, arelisted in Table II. These elastic properties werededuced from measurements of the longitudinaland transverse sound velocities (15). The pulse-echo measurements were performed on plates2 mm to 3 mm thick, using appropriate transduc-ers to excite either the longitudinal (at 10 MHz) orthe transverse (2.5 MHz) acoustic mode. ThePoisson’s ratio of 0.37 is typical for precious met-als. The Young’s modulus of 139 GPa to 145 GPais comparable to that of the conventional PdRualloy (148 GPa). It lies between those of 18 caratAu alloys (90 GPa to 110 GPa) and 950 Pt alloys(approximately 170 GPa to 210 GPa). Regardingspecific stiffness, E/ρ, the PdAlRu alloys with


CW CW

CW CW

An AH An AH

An AH An AH

Rp

0.2, M

Pa

Rm

, M

Pa

A50, %

Vic

kers

harn

ess, H

V

1000

800

600

400

200

0

0

10

20

30

40

50

0

200

400

600

800

1000

1200

0

50

100

150

200

250

300

350

PtRuGa

5N red gold

PdRu

PdAl2.8Ru1.7 PdAl0.9Ru3.6

AuPdCu 3N yellow gold

Fig. 6 Comparison of mechanical properties of two PdAlRu alloys with commonly used precious metal alloys: a 950 Pt alloy (PtRuGa); a 950 Pd alloy (PdRu); a 13 wt.% Pd-containing 18 carat white gold (AuPdCu); 3N yellowgold; and 5N red gold. The comparison is made for 75% cold-worked (CW), annealed (AN), and age-hardened (AH)materials. Rm = tensile strength; Rp0.2 = conventional yield strength; A50 = fracture strain; HV = Vickers hardness

densities, ρ, in the range 10.5 g cm–3 to 11.6 g cm–3

slightly exceed Pt alloys (ρ ≥ 20 g cm–3) and clearlyoutperform Au alloys (ρ ≥ 15 g cm–3).

Colour The CIELab colorimetric indices L* (lightness),

a* (red-green chromaticity index) and b* (yellow-blue chromaticity index) of polished samples weredetermined using a spectrophotometric colorimeter(Konica Minolta CM-3610d spectrophotometer)(16). The measurement was carried out in a stan-dard configuration with D65 illumination, a 10ºobserver, and in specular component included(SCI) mode. The ideal white would return(L*/a*/b*) indices of (100/0/0). The measuredvalues are (84/1/4.5) for Pd95.5Al2.8Ru1.7 and(86/0.9/4.1) for Pd95.5Al0.9Ru3.6. These values arecomparable to those of standard 950 PdRu, andcloser to the colour of the platinum alloy 950 PtRu(87.7/0.7/3.4) than to ‘premium’ 18 carat whitegold (82/> 1.5/> 6). However, the colour indicesof the two PdAlRu alloys suggest that the effect ofaluminium is to add a slight yellowish tinge and tosomewhat diminish the brightness.

For the classification of white gold alloys, asimple colour grading system based on the ASTMD1925 (1988) yellowness index (YI) has recentlybeen proposed (17). Within this system, the lowerthe YI the whiter the alloy. The whitest metals andalloys such as silver or 950 PtRu have values ofYI ≈ 8. The PdAlRu alloys attain YI ≈ 10, which iscomparable to pure Pd or Pt. White gold alloys, incontrast, have substantially higher indices, atYI ≥ 15.

WorkabilityFigure 4 shows another characteristic feature of

the two PdAlRu alloys: their yield strengths do not

steadily approach their tensile strengths withincreasing cold work. Rather, the gap between thetwo parameters remains relatively large, thus facil-itating the forming of complex and asymmetricshapes.

The good workability of the two alloys wasconfirmed by the fabrication of watch cases, backsand bezels by employing rolling, stamping andannealing operations. Plate ingots with surfacesmachined to eliminate possible microcracks andflaws were used as a starting material. The plateswere easily rolled to over 90% reduction withoutintermediate annealing. In accordance with thedata in Figure 5, the hardness rose by only about40 HV upon increasing the cold work from 23%to 95% reduction. Blanks were then roughlypunched out from bands of thickness 8.8 mm,followed by fine punching for improved surfacefinish and dimensional tolerances. The final shap-ing of larger series of components by progressivedie stamping is in progress.

The most intriguing observation during theseoperations was the pronounced tendency of bothalloys to heat up considerably during plastic work.While heating to a certain extent is usual forrolling processes, the heating up of a disc duringpunching to temperatures so high that it cannotbe touched by hand is extraordinary. This signifi-cant temperature rise during plastic deformationmight be related to the low work hardening bypromoting dynamic recovery.

Use of the Ceramic FusionTechnique with PdAlRu Alloys

Inspired by the dental technique of ceramicveneering of precious metals, the feasibility of fus-ing coloured ceramic overlays on PdAlRu alloysfor decorative purposes was investigated. In the


Table II

Density, Young’s Modulus and Poisson’s Ratio of PdAlRu Alloys

Alloy State Density, Young’s modulus, Poisson’s ratio,

ρ, g cm–3 E, GPa ν

Pd95.5Al2.8Ru1.7 Annealed 10.8 139 0.37

Pd95.5Al0.9Ru3.6 Annealed 11.4 145 0.37

dental technique, Pd-containing alloys are in factpreferred. Pd oxidises more readily than Au or Pt,which guarantees a better bonding to the ceramic.The presence of Al in the PdAlRu alloys is certain-ly favourable in this respect. The dental sectorcommercialises a broad range of ceramic materialswith coefficients of thermal expansion (CTE) inthe range 8 × 10–6 K–1 to 14 × 10–6 K–1 (18, 19). TheCTE of Pd is 12 × 10–6 K–1, and alloying with atotal of 5 wt.% Al and Ru is not expected tochange this value significantly. A close match ofthe ceramic CTE to the metal CTE is important toavoid cracking, notably during cooling after thefiring process.

Two types of commercial dental ceramics weretested: VITA VM®13 veneering material for inten-sive or translucent colours, and the VITA Akzent®

stain powder for pitch black dyeing (19). Theceramics were either applied as overlays or filled into trench patterns machined into the PdAlRudiscs.

The ceramic-to-metal fusion was performedfollowing the directions of the ceramic supplier(19). In short, it consists of preparing the metalsurface by sandblasting and controlled thermaloxidation. Different ceramic layers are thenapplied and fired one after the other at 890ºC forone to two minutes: a first layer to promote cohe-sion, a second opaque layer, and a finalglass-ceramic coloured layer. Additional layersmay be necessary in order to fill in possible gapsproduced upon firing.

Figure 7 exemplifies PdAlRu discs preparedand polished by the methods described above,with differently coloured ceramic inlays. Thecolours are uniform and no pores or cracks areapparent.

ConclusionsIn search of 950 Pd alloys with improved

mechanical properties, PdAlRu alloys proved partic-ularly promising. The PdAlRu alloys presented inthis paper possess beneficial characteristics forapplications in jewellery, and in particular in watch-making. The palladium content of 95 wt.% iscommon to most countries. The PdAlRu alloys arewhiter than most 18 carat white gold alloys.Furthermore, they are compatible with the dentalveneering technique, which opens up the potentialfor decorating articles with ceramic ornaments inappealing colours. The PdAlRu alloys exhibit excel-lent workability and forming characteristics, similarto those of commonly used 950 Pd alloys. At thesame time, they exhibit much higher strength andhardness, more comparable to those of gold or plat-inum alloys. Moreover, the mechanical propertiescan be tuned in an extended range by varying theAl:Ru ratio. Upon cold working, for a given strain,the yield stress increases much less than it does inother precious metals, while the tensile strengthincreases in broadly similar fashion. This character-istic imparts to the alloys enhanced plasticity andexcellent workability.


Fig. 7 PdAlRu alloy discs with ceramic inlays

1 S. A. Forrest and B. Clarke, ‘End-Users, Recyclers andProducers: Shaping Tomorrow’s PGM Market andMetal Prices’, in “International Platinum Conference‘Platinum Surges Ahead’”, Sun City, South Africa,8th–12th October, 2006, Symposium Series S45, TheSouthern African Institute of Mining and Metallurgy,Johannesburg, South Africa, 2006, p. 307

2 B. Libby, ‘Palladium Premieres’, MJSA Journal, March2006, p. 35

3 “The Santa Fe Symposium on Jewelry ManufacturingTechnology 2008”, ed. E. Bell, Proceedings of the22nd Symposium in Albuquerque, New Mexico,U.S.A., 18th–21st May, 2008, Met-Chem ResearchInc, Albuquerque, New Mexico, U.S.A., 2008

4 Kitco, Inc, Past Historical London Fix: http://www.kitco.com/gold.londonfix.html (Accessed on3rd July 2009)

5 W. Hume-Rothery, R. E. Smallman and C. W. Haworth,

References

“The Structure of Metals and Alloys”, 5th Edn., TheMetals and Metallurgy Trust, London, U.K., 1969,407 pp

6 G. Beck, in “Edelmetall-Taschenbuch”, 2nd Edn., ed.A. G. Degussa, Hüthig-Verlag, Heidelberg, Germany,1995, p. 217

7 The PGM Database:http://www.platinummetalsreview.com/jmpgm/index.jsp (Accessed on 3rd July 2009)

8 J. R. Hirst, M. L. H. Wise, D. Fort, J. P. G. Farr andI. R. Harris, J. Less-Common Met., 1976, 49, 193

9 J. Evans, I. R. Harris and L. S. Guzei, J. Less-CommonMet., 1979, 64, (2), P39

10 A. Blatter, J. Brelle and R. Ziegenhagen, PX HoldingSA, ‘Alliage à Base de Palladium’, Swiss Appl.CH00032/08; 2008

11 P. Battaini, 8853 SpA, ‘High-Hardness Palladium Alloyfor Use in Goldsmith and Jeweller’s Art andManufacturing Process Thereof’, Italian Appl.TO2006/0086; U.S. Appl. 2008/0,063,556

12 H. W. King, Bull. Alloy Phase Diagrams, 1982, 2, (4),527

13 F. M. Smits, Bell Syst. Tech. J., 1958, 37, 711

14 R. Hill, “The Mathematical Theory of Plasticity”,Oxford Classic Texts in the Physical Sciences, OxfordUniversity Press Inc, New York, U.S.A., 1998, 366 pp

15 “Nondestructive Testing Handbook”, Volume 7,“Ultrasonic Testing”, eds. A. S. Birks, R. E. Green,Jr. and P. McIntire, American Society forNondestructive Testing, Columbus, Ohio, U.S.A.,2007, 600 pp

16 “Precise Color Communication: Color Control fromPerception to Instrumentation”, Product Applications,Konica Minolta Sensing Inc, Japan, 1998: http://www.konicaminolta.com/instruments/knowledge/color/pdf/color_communication.pdf (Accessed on3rd July 2009)

17 S. Henderson and D. Manchanda, Gold Bull., 2005,38, (2), 55

18 Wieland Dental online: Products: Veneering Ceramic:http://www.wieland-dental.de/produkte/verblendkeramik/page.html?L=1 (Accessed on 3rdJuly 2009)

19 VITA Zahnfabrik website: http://www.vita-zahnfabrik.com/ (Accessed on 3rd July 2009)


The Authors

Julien Brelle graduated in MaterialsScience and Engineering from theÉcole Polytechnique Fédérale inLausanne, Switzerland (2005), with aspecialisation in metal matrixcomposites. He is now working as aResearch Engineer at PX Group, aproducer of metal products for thewatch, jewellery and medical sectors.He is mainly involved in the

development of speciality alloys and related processing.

After his Ph.D. in Physics (1986),Andreas Blatter led a research group atthe Institute of Applied Physics in Berne,Switzerland, and spent a year at the IBMAlmaden Research Center, U.S.A, as aVisiting Scientist. His research wasfocused on non-equilibrium laserprocessing, thin films and metallicglasses. Since 1996, he has been theR&D Director of PX Group. His main

research topics include precious metals and speciality alloysand their related technologies, as well as corrosion andbiocompatibility studies.

René Ziegenhagen received his degree inMaterials Science and Engineering fromthe École Polytechnique Fédérale inLausanne, Switzerland (1986). He wasthen involved in the research of preciousmetals and the development of newindustrial processes, such as metalinjection moulding and forging, beforejoining Cartier in the Richemont Group asa Senior Project Manager. At Cartier, his

main concerns include the quest for new materials and newproduction technologies to meet requirements and regulationson biocompatibility and ecotoxicity.

198

The 23rd annual Santa Fe Symposium® was heldin Albuquerque, New Mexico, U.S.A., from17th–20th May 2009 (1). Attendance was down onprevious years, perhaps reflecting the impact of thecurrent recession on the jewellery industry in theU.S.A., although surprisingly representation fromEurope was stronger than in previous years. Onceagain, the organisers had put together a strong,attractive programme covering all areas of activity,although platinum- and palladium-centred topicswere fewer than last year. Having said that,palladium’s position as a relatively new metal forjewellery sustained its prominence at the conference.

The Platinum Group MetalsThe interest in platinum group metals (pgms)

remains strong, judging by the reaction to the lucidpresentation by Mark Danks (Johnson MattheyNew York, U.S.A.). His topic was ‘The PreciousMetal Price Equation’ and he reviewed the pricehistory of platinum and palladium, coinciding withPlatinum Week in London, U.K., and the publica-tion of the Johnson Matthey “Platinum 2009”market review (2). 2008 was a year of mixed for-tunes, with the price of platinum starting high,rising even further during the first half-year beforedropping severely during the third quarter due tosoftening demand in both the industrial and jew-ellery sectors, although there was some recovery atthe year end. Danks analysed the supply anddemand for platinum and palladium and the rea-sons behind the changes compared to 2007. Hecovered the fall in demand from the automotivesector, the rise in exchange traded funds (ETFs)and examined trends in jewellery demand for plat-inum and palladium. The high price of platinuminevitably had a negative impact on jewellerydemand, while demand for palladium in this sector

increased in Europe and the U.S.A., due toimproved technical knowledge of the metal and itsfavourable price compared to gold and platinum.

Palladium On the technical side, Paolo Battaini (8853

SpA, Italy) gave another excellent presentation onthe casting of 950 palladium alloys, using an inno-vative melting technique borrowed from the dentalindustry. Titled ‘Production of Hard 950Palladium-Based Jewellery Using an Arc MeltingMethod under Argon Protection’, Battaini showedhow employing arc plasmas for melting (as in tung-sten inert gas (TIG) welding) in the investmentcasting of palladium jewellery can overcome someof the problems found with conventional castingprocesses. In particular, it enables good control ofthe melting and casting atmosphere as well asallowing rapid melting to the high temperaturesrequired. Use of argon gas is preferred over heliumto avoid overheating of the melt. Casting trialswere carried out on a hard 950 palladium alloy con-taining gallium, indium and other minor alloyingadditions. The alloy development was described inBattaini’s earlier paper, presented in 2006 (3): inthe as-cast condition, it has a Vickers hardness of190 HV.

Casting was carried out in an Orotig Srl‘Speedcast 220MJ’ machine, which is also used tocast platinum and titanium jewellery. Casting isaccomplished by rotating the chamber to gravity filland applying an argon overpressure to the castingmould and flask. During melting, the tungsten elec-trode is moved over the melt in a circular motion.Three types of melting crucible were trialled: alumi-na, fused quartz (silica) and zirconia, along withfour types of mould investment: a two-part phos-phate-bonded, quick burn-out dental investment, a

Platinum Metals Rev., 2009, 53, (4), 198–202

The 23rd Santa Fe Symposium on JewelryManufacturing TechnologyNOVEL MELTING APPROACH FOR 950 PALLADIUM CASTINGS SHOWS PROMISE

Reviewed by Christopher W. CortiCOReGOLD Technology Consultancy, Reading, U.K.; E-mail: [email protected]

DOI: 10.1595/147106709X474208

one-part water-bonded platinum investment con-taining chopped glass fibres, the same without glassfibres, and a two-part phosphoric acid-bondedinvestment for platinum. The arc current employedwas related to the melt size and casting was accom-plished in about forty seconds after arc ignition.Zirconia crucibles were preferred for melting asless current is needed (due to zirconia’s lower ther-mal diffusivity compared to silica and alumina),allowing for better process control.

Castings were evaluated for pattern filling, sur-face quality and defects, including cracks, fins andporosity; additionally, metallographic examinationand mechanical property assessments were made.Other factors such as devesting of the castingsand recastability of scrap were also examined. Ingeneral, the two-part platinum investment gavethe best results for the 950 palladium alloy. Detailreproduction was good with a smooth surface(Figure 1), and there was no reaction between

metal and investment. Flask temperature (650ºCand 750ºC) made little difference to the slight oxi-dation observed, although if higher temperaturesare used a vitreous layer may be formed. The two-part dental investment resulted in castings withheavy oxidation and hot tearing. The latter prob-lem was also seen with the glass fibre-containinginvestment, suggesting that both investments havepoor thermal expansion compatibility and/or toohigh a level of stiffness.

Pattern filling was generally good with allinvestments, attributed to the argon overpressureapplied just after pouring. Recastability was good,even with use of 100% scrap as the charge if prop-erly cleaned. Normal casting results in largedendritic grains, but in this study metallographicexamination revealed a moderate as-cast grain sizeof about 300 μm, with some microsegregationacross dendrites. The grain size increased a little inthicker sections.


2 mm

500 μm

1 mm

1 mm

2 mm

Fig. 1 As-cast surfaces of the 950 palladium alloy after water jet removal of the two-part platinum investment. Surfaceis smooth, with slight defects in the wax reproduced – particularly evident on the grid. (Inset: Scanning electronmicroscope image of the grid. The black particles are the only remaining traces of the investment material)(Courtesy of Paolo Battaini, 8853 SpA, Italy)

Gas porosity was noted frequently but washardly detected after polishing. Care was neededto avoid shrinkage porosity in thick (> 3 mm) sec-tions, but the normal precautions to prevent thisoccurrence in other precious metals also work forpalladium alloys. Battaini noted that the feedsprues should be optimised to assist directionalsolidification. He concluded that arc meltingproved to be a reliable method for investmentcasting of this 950 palladium alloy, and that shortmelting times and an argon atmosphere help toavoid alloy contamination. He also reiterated thatthe right choice of investment remains essentialto obtain good results and recommended that aspecific investment tailored for palladium shouldbe developed.

Platinum On the platinum front, technology is more

established and attracted less attention. However,Jurgen Maerz (Platinum Guild International,U.S.A.) gave an interesting presentation on theinvestment casting of 950 platinum alloys,‘Historic Casting Methods’. This was a review ofold methods used to cast platinum in the early daysof jewellery making and, more specifically, of aproject in which the old manual sling castingmethod was reproduced in a modern guise andshown to produce acceptable castings. It was wellillustrated by a video clip of the whole process. Itis something only likely to be used by the smallcraft jeweller – however, whirling hot molten plat-inum around one’s head may not meet modernworkplace health and safety requirements!

Metallurgy and ManufacturingA number of papers were presented that cov-

ered all the jewellery precious metals: gold, silver,platinum and palladium. Starting the conference,Chris Corti (COReGOLD, U.K.) gave the thirdpart of his ongoing ‘Basic Metallurgy’ series on‘Cracks, Defects and Their Prevention’ (4, 5). Thisexamined the causes of cracking and other defectscommonly encountered while manufacturing jew-ellery. These included embrittlement by impuritiesand minor alloying additions such as silicon, whichcan manifest itself as hot tearing and quench

cracking during casting; these can occur in all fourprecious metals. Other causes include cracking dueto shrinkage porosity, inclusions and pipes fromcasting, and fire cracking from annealing. Stresscorrosion cracking can occur after manufacture,when the jewellery is in service.

Hardness and its significance was a populartopic in 2008 (6), and it continued to attract atten-tion in 2009. Gary Dawson (Goldworks JewelryArt Studio, U.S.A.) examined the effect of bur-nishing jewellery on hardness of the surface layerfor a range of materials, including 950 platinumand 950 palladium alloys. This utilised the ‘drophardness’ test to determine hardness, which is easyto do in the absence of proper hardness testingequipment. This study concluded that, as had beenfound earlier, burnishing with steel media in eithera rotary tumbler or vibratory machine leads tohardening of the surface, rotary tumbling having alarger effect and giving a smoother surface. Thedepth of hardening was lower for the 950 platinumalloy than for the 950 palladium alloy, althoughboth saw larger relative hardness increases thanthe gold or silver alloys tested. Dawson noted thatfinal polishing after burnishing could remove thehardened layer.

‘Hardness and Hardenability’ was a topic pre-sented by John Wright (Wilson-Wright Associates,U.K.), author of the Johnson Matthey jewellerytechnical manual “An Introduction to Platinum”(7). He investigated the indentation hardness testand how work hardening affects the value mea-sured, and explained why it is not easy to correlateresults measured by one test with those measuredby another type, or with tensile data.

Improved wear, scratch and tarnish resistancesof jewellery are desirable features in jewellery man-ufacture. Marco Actis Grande (Turin Polytechnic,Italy) spoke about ‘Transparent Coatings Appliedin Jewellery: A Challenge for Success?’. Using plasma-enhanced chemical vapour deposition(PECVD), he deposited thin non-stoichiometricsilicon oxide coatings on sterling silver and per-formed a range of corrosion, tarnish and weartests. These showed that a 100 nm-thick coatinggave the best improvement in resistance to corro-sion and tarnish. Actis Grande concluded that


PECVD can be one method to improve corrosionand tarnish resistance of sterling silver. Wear testresults are awaited. These coatings may have appli-cation to the other precious metals for improvedwear resistance, especially where the alloys are relatively soft.

Looking to the future, Joe Strauss (HJECompany, Inc, U.S.A.) gave an excellent reviewof how rapid prototyping is developing into amanufacturing process, in ‘Rapid Manufacturing(RM) and Precious Metals’. Noting that computeraided design/computer aided manufacturing(CAD/CAM) and rapid prototyping are becomingfamiliar technologies in the jewellery industry, helooked at how these technologies are being devel-oped into manufacturing processes and how thesemight relate to jewellery manufacture in the future.There are a number of RM technologies emerging,many based on metal powders as the starting mate-rial: selective laser fusing and sintering, electronbeam melting, laser powder forming and selectiveinkjet binding. These techniques are already in usein dental, biomedical, Formula 1 motor racing andthree-dimensional artwork applications, where theattraction is the ability to customise components.Strauss believes that the use of these techniques injewellery manufacture should have the objective ofutilising their key attributes, namely: reduction oflead time to market, the creation of unique shapes,the use of novel materials and the possibility forinnovative design features, rather than competingwith current manufacturing technologies. Thereare some challenges and issues, he admitted, suchas quality of surface finish, affordability of equip-ment and material costs and availability.

Investment casting is probably the most widelyused manufacturing process in jewellery. It com-prises many steps, starting with master models andrubber mould manufacture. Tyler Teague (JettResearch, U.S.A.) gave an excellent paper,‘Technical Model Making (It’s Not Just the Size ofYour Sprue That Counts)’, which examined vari-ous factors including the adaptation of traditionalcasting techniques to jewellery, in particular the useof risers, to prevent shrinkage porosity. HubertSchuster (Consultant, Italy) looked at rubbermould manufacture in his absorbing presentation

‘Innovative Mould Preparation and Cutting forVery Thin and High Precision Items’. Thisinvolved use of different rubber compounds inparts of the mould and expert cutting after vulcan-ising.

General InterestBack to basics once again with Klaus Wiesner

(Wieland Dental + Technik GmbH & Co KG,Germany) who gave an overview of precious metaltube manufacturing techniques and some of theproblems encountered, in his presentation ‘TubeManufacturing – Some Basics’.

There were several presentations on decorativeeffects in jewellery: purple and blue gold alloyswere discussed by Ulrich Klotz (FEM, Germany)and Jörg Fischer-Bühner (Legor Srl, Italy); a pre-sentation on an ancient Japanese technique knownas ‘mokume gane’ that bonds many layers of pre-cious metals into a single patterned piece was givenby Chris Ploof (Chris Ploof Studio, U.S.A.) (Figure2) (8); a description of colour gradients in carat


Fig. 2 Triple white mokume gane ring, with 950palladium alloy, 14 carat palladium white gold and silver(Courtesy of Chris Ploof Studio, U.S.A.)

golds by gradient casting was given by Filipe Silva(University of Minho, Portugal); and a scientificstudy of Japanese patination techniques was pre-sented by Cóilín Ó Dubhghaill and Hywel Jones(Sheffield Hallam University, U.K.).

Other papers included a study of the practicalapplication of some new (tarnish-resistant) sterlingsilvers by Mark Grimwade (The WorshipfulCompany of Goldsmiths, U.K.), and discussionsof electromechanical polishing of silver by AlexVerdooren (Rio Grande, U.S.A.) and hot tearing incasting sterling silver by Daniele Maggian(ProGold Srl, Italy). These were followed by areview of gold-filled products by Rick Greinke(Award Concepts, Inc, U.S.A.), and by the discus-sion of unconventional manufacturing techniquesfor models and prototypes by Michael Jones(Evangel Arts, U.S.A.), age-hardenable carat goldsby Grigory Raykhtsaum (Sigmund Cohn Corp,U.S.A.) and design of fire assay laboratories byRajesh Mishra (A-1 Specialized Services andSupplies, Inc, U.S.A.).

A Lifetime Achievement Award was presentedto John C. Wright, who has made a significantcontribution over many years to further ourknowledge and understanding in jewellery manu-facture, particularly in platinum (see for example(7, 9)). Professor Wright has presented severaltimes at the Symposium, and also wrote the WorldGold Council “Technical Manual for GoldJewellery” (10).

Concluding RemarksInterest in palladium as a new jewellery metal

remains high, while platinum technology is betterknown and established. The conference continuesto provide good coverage of general techniques injewellery manufacture, of interest to workers in allthe precious metals. The Santa Fe Symposium®

proceedings are published as a book and thePowerPoint® presentations are available on CD-ROM. They can be obtained from the organisers(1). The 24th Santa Fe Symposium will be held inAlbuquerque on 16th–19th May 2010.


The ReviewerChristopher Corti holds a Ph.D. in Metallurgyfrom the University of Surrey (U.K.) and hasrecently retired from the World Gold Councilafter thirteen years, the last five as aconsultant. During this period, he served asEditor of Gold Technology magazine, GoldBulletin journal and the Goldsmith’s CompanyTechnical Bulletin. He continues to consult inthe field of jewellery technology and, as arecipient of the Santa Fe Symposium®

Research, Technology and Ambassador Awards, he is a frequentpresenter at the Santa Fe Symposium.

1 The Sante Fe Symposium:http://www.santafesymposium.org/ (Accessed on3rd August 2009)

2 D. Jollie, “Platinum 2009”, Johnson Matthey, Royston,U.K., 2009: http://www.platinum.matthey.com/publications/Pt2009.html (Accessed on 3rd August2009)

3 C. W. Corti, Platinum Metals Rev., 2007, 51, (1), 194 C. W. Corti, ‘Basic Metallurgy of the Precious Metals’,

in “The Santa Fe Symposium on JewelryManufacturing Technology 2007”, ed. E. Bell,Proceedings of the 21st Symposium in Albuquerque,New Mexico, U.S.A., 20th–23rd May, 2007, Met-ChemResearch Inc, Albuquerque, New Mexico, U.S.A., 2007,pp. 77–108

5 C. W. Corti, ‘Basic Metallurgy of the Precious Metals– Part II’, in “The Santa Fe Symposium on Jewelry

Manufacturing Technology 2008”, ed. E. Bell,Proceedings of the 22nd Symposium in Albuquerque,New Mexico, U.S.A., 18th–21st May, 2008, Met-ChemResearch Inc, Albuquerque, New Mexico, U.S.A., 2008, pp. 81–101

6 C. W. Corti, Platinum Metals Rev., 2009, 53, (1), 217 “An Introduction to Platinum”, Johnson Matthey New

York, U.S.A.: http://www.johnsonmattheyny.com/technical/platinumTechManual (Accessed on 3rdAugust 2009)

8 Chris Ploof Studio, Traditional Mokume Gane:http://www.chrisploof.com/traditionalpattern.html(Accessed on 3rd August 2009)

9 J. C. Wright, Platinum Metals Rev., 2002, 46, (2), 6610 J. C. Wright, “Technical Manual for Gold Jewellery –

A practical guide to gold jewellery manufacturingtechnology”, World Gold Council, London, U.K., 1997

References

The third Novel Chiral Chemistries Japan(NCCJapan) Conference and Exhibition was heldin Tokyo on 18th and 19th April 2009 (1). The sec-ond meeting had been held in 2007 (2) and the firstin 2006. All meetings in the series have followed asimilar format, with keynote addresses and sup-porting lectures, although this time there weresome dual presentations in which two speakersfrom the same company gave complementary talkson slightly different topics within a single time slot.Professor Takao Ikariya (Tokyo Institute ofTechnology, Japan) and his team, in particularKyoko Suzuki, must be congratulated for theexcellent job they did to ensure that the conferenceran smoothly. As in previous meetings, ProfessorIkariya put together an exciting mix of speakersfrom both academia and industry across the world.There were around 130 attendees, with the major-ity being from Japan.

During the coffee and lunch breaks there wasan exhibition by companies with products mainlyassociated with chiral chemistry. The exhibitorsranged from companies that provide biocatalystsand chemical catalysts including ligands, to chro-matography, chemistry services and instrumentmanufacturers.

Keynote PresentationsThe opening keynote address was given by

Professor Yoshiji Takemoto (Kyoto University,Japan) on asymmetric catalysis with multifunction-al ureas. The reactions described includedasymmetric versions of the Michael and Mannichreactions, hydrazination and the aza-Henry reac-tion with 1,3-dicarbonyl compounds, as well asPetasis-type additions to quinolines and conjugateadditions to enones.

The second keynote address was given byProfessor Jan-Erling Bäckvall (Stockholm Univer-sity, Sweden). This lecture covered his work on the

simultaneous use of bio- and chemocatalysis toenable dynamic kinetic resolutions (DKR) to becarried out. The initial work was performed withsecondary alcohols. The readily available enzyme,Candida antarctica lipase B (CALB) (Novozym®

435), which is derived from a yeast, is used to acy-late one enantiomer of a secondary alcohol. Aruthenium catalyst then racemises the unreactedenantiomer. Initially the Shvo catalyst, 1, was usedbut the racemisation is slow and requires heating togive acceptable reaction rates. Use of themonomeric ruthenium catalyst 2 provides fasterreactions, even at ambient temperatures.

CALB provides the (R)-acetate, while a spe-cially treated subtilisin Carlsberg enzyme gives the(S)-product ester. With 1,3-dihydroxy com-pounds, the selectivity of the enzyme ensures highselectivity for the (R,R)-diacetoxy product.However, due to the slow racemisation rates withthe Shvo catalyst system, significant amounts ofmeso-products were formed with 1,4- and 1,5-diols.Use of the faster catalyst 2 alleviates this problem.Analogous uses of the concept have beenemployed for the DKR of chlorohydrins, aminesand allenic alcohols.


Novel Chiral Chemistries Japan 2009PGMs RETAIN THEIR PIVOTAL ROLE IN ASYMMETRIC CATALYSIS

Reviewed by David J. AgerDSM, PMB 150, 9650 Strickland Road, Suite 103, Raleigh, NC 27615, U.S.A.; E-mail: [email protected]

DOI: 10.1595/147106709X474226

RuH

Ru

OH

O

Ph

Ph

Ph

Ph

Ph

PhPh

Ph

OCCOCO OC1

RuCl

Ph

Ph

Ph

Ph

Ph

OCCO2

The third keynote address was given byProfessor Hisashi Yamamoto (University ofChicago, U.S.A.) on the uses of Brønsted acids inorganic synthesis. The emphasis of the talk was onthe use of triflimide, (CF3SO2)2NH, as a superacidthat can regenerate itself during a Mukaiyama aldolreaction. The use of the tris(trimethylsilyl)silyl(TTMS) group as a ‘super silyl’ group also makesthe enol ether more reactive.

Asymmetric CatalysisIn addition to these keynote addresses there

were fifteen other presentations. Topics includedthe uses of biocatalysis, transition metal catalysisand the synthesis of target molecules, among others. In line with the emphasis of this publica-tion, those talks relating to the use of platinumgroup metals (pgms) have been highlighted.

Fred Hancock (Johnson Matthey Catalysis andChiral Technologies, U.K.) gave an overview ofsome case histories in which Johnson Matthey hadlooked for an appropriate catalyst to perform anasymmetric transformation. He described theadvantages of chemocatalytic and enzymatic meth-ods for the reduction of carbonyl compounds fora number of example systems. The reduction ofaryl ketones can be achieved in high yield and withhigh enantioselectivity by the system RuCl2[(R)-P-Phos][(S)-DAIPEN], 3a and 4, in a manner anal-ogous to the method developed by Noyori (3). Theuse of this system with xyl-P-Phos, 3b, was illus-trated for a pharmaceutical application as part ofthe synthesis of Nycomed’s imidazo[1,2-a]pyridineBYK-311319. The P-Phos family of ligands canalso be used in the catalyst system [RuCl2(P-Phos)(DMF)n] (DMF = N,N-dimethylformamide),

for the reduction of α,β- and γ,δ-enoic acids forpharmaceutical applications, such as in the preparation of an intermediate for Solvay’sSONU 20250180. α,β-Enoic acids can also bereduced by an iridium or rhodium catalyst withMe-BoPhozTM, 5, as the chiral ligand or by arhodium–Xyl-PhanePhos, 6, system.

André de Vries and David Ager (DSM, TheNetherlands and U.S.A., respectively) gave a jointpresentation. de Vries described the advantages ofperforming asymmetric hydrogenations of unsatu-rated carbon–carbon multiple bonds with arhodium catalyst using the MonoPhosTM family ofligands, 7 (4). The method can be automated,which allows for rapid screening of products.


N

N

OMe

MeO

MeO

OMe

PAr2

PAr2

3

a Ar = Ph ((R)-P-Phos)

b Ar = xyl ((R)-xyl-P-Phos)

H2N

H2NOMe

OMe

4 (S)-DAIPEN

Fe

N

PPh2 PPh2

5 (R)-Me-BoPhozTM

P(xyl)2

P(xyl)2

6 (R)-Xyl-PhanePhos

R4

R4

R3

O

O

R3

R5

R5

P NR1R

2

7 MonoPhosTM

family of ligands

Higher reaction rates and enantioselectivities canbe observed when two different monodentate lig-ands are used at the same time. This has resultedin an economical process for the preparation ofpart of Novartis’ renin inhibitor, Aliskiren. Thephosphoramidite MonoPhosTM ligands are alsouseful for the reduction of carbonyl groups,including β-keto esters, with ruthenium as themetal. Iridium systems with phosphoramidites canbe used to prepare phenylalanines by asymmetrichydrogenation, and also provide high selectivity inthe reduction of imines. Ager discussed enzymaticmethods to prepare cyanohydrins with high enan-tioselectivity, and the development of theindustrial production of DSM’s PharmaPLETM, arecombinant pig liver esterase that can be used inpharmaceutical applications.

Professor Andreas Pfaltz (University of Basel,Switzerland) continued the asymmetric hydro-genation theme with his iridium-catalysedasymmetric reduction of unfunctionalised alkenesin the presence of P,N-ligands. In addition to thewell-established system 8, which can be used witha wide variety of alkene substitution patterns, thephosphinooxazolines, 9, have also proven useful,particularly with trisubstituted alkenes. For thisclass of reductions, it is particularly important touse a non-nucleophilic counterion for the metal,such as tetra[3,5-bis(trifluoromethyl)phenyl]borate(BArF).

Kunihiko Murata (Kanto Chemical Co, Inc,Japan) described the development of the rutheni-um-based asymmetric transfer hydrogenationcatalyst 10 for the reduction of ketones, whichremoves the need for a chiral phosphine ligand.The diamine provides the asymmetry. This catalystcan also be used to carry out asymmetric Henryand Michael reactions.

Ian Lennon (Chiral Quest, Inc, U.K.) describedthe chemistry and uses of a number of ligand sys-tems developed by Chiral Quest. C3-TunePhos, 11,provides excellent enantioselectivity for the reduc-tion of β-keto esters. The analogue C3*-TunePhos,12, extends this to ketones and α-keto esters aswell as retaining its selectivity with β-keto esters.TangPhos, 13, has proven to be a useful ligand inthe rhodium-catalysed reduction of dehydroaminoacids, itaconates and enamides. The latter class ofcompounds can now be accessed from oximes bya rhodium-on-carbon-catalysed hydrogenation inthe presence of acetic anhydride. The analogue ofTangPhos, DuanPhos, 14, provides excellentstereoselectivity for the reduction of function-alised aryl alkyl ketones, while BINAPINE, 15,provides access to β-amino esters.

Christophe Le Ret (Umicore AG & Co KG,Germany) described a different aspect of asym-metric hydrogenation: the formation ofmetal–ligand complexes and the influence of themetal precursor. For rhodium, an example ligandwas MandyPhosTM, 16. For the asymmetricreduction of (Z)-acetamidocinnamic acid methylester, with Rh(nbd)2 (nbd = 2,5-norbornadiene)as the metal source, in situ formation of the cata-lyst or the use of the P,N-complex gave a slowerhydrogenation rate than the P,P-complex system.With ruthenium, it was found that the use ofbis(η5-2,4-dimethylpentadienyl)ruthenium(II), 17,was superior for complex formation withMandyPhosTM and other ferrocene-based ligands.

Wataru Kuriyama (Takasago InternationalCorp, Japan) described the synthesis of chiral alco-hols by the catalytic reduction of esters. The systemis based on a ruthenium–diamine complex, 18. Forhigh enantioselectivity, the stereogenic centre hasto be present in the substrate, as it is in α-alkyl, β-amino, β-alkoxy, β-hydroxy and α-hydroxy esters.


PAr2 N

O

R2

N

O

PAr2

Ph3

8 9

Ar = Ph or o-Tol

NH2

N

Ru

Ph

Ph X

R1SO2

R2

10

X = Cl

R1

= aryl or alkyl

Ar–R2

= cymene,

mesitylene or

hexamethylbenzene

The key to success was performing the reactions inthe absence of base.

Professor Ken Tanaka (Tokyo University ofAgriculture and Technology, Japan) presented onrhodium-catalysed [2 + 2 + 2] cycloadditions forthe preparation of axial chiral aromatic compounds.The products can be biaryl systems or others withhindered rotation, such as benzamides. The ligandsused for the reactions are BINAP, 19, and deriva-tives, such as H8-BINAP, 20, and SEGPHOS®, 21.

David Chaplin (Dr Reddy’s Laboratories Ltd,U.K.) described asymmetric hydroformylationreactions. Linear products are most commonlyformed from an achiral hydroformylation reaction,but the product aldehydes can be substrates for awide variety of reactions. For an asymmetric version of the reaction, regioselectivity as well asenantioselectivity must be considered, as thebranched aldehyde is usually the required productbecause it generates the stereogenic centre. This


PPh2

PPh2

O

O

PAr2

PAr2

O

O

P P

H

t-Bu

H

t-Bu

P P

t-Bu t-Bu

HH

P P

t-Bu t-Bu

HH

11 C3-TunePhos

12 C3*-TunePhos

13 TangPhos

15 BINAPINE

H

tBu

tBu

tBu

14 DuanPhos

tBu

tBu

tBu

Ar = Ph, 4-MePh,

3,5-di-tBuPh, 3,5-diMePh

or 4-MeO-3,5-di-tBuPh

16 MandyPhos 17

Me2N

Fe PPh2

Ph

PPh2

Ph

NMe2

Ru

NH2

H2

N

Ru

Ph

Ph

P

P

Ph Ph

PhPh

H

H

BH3 18

Ph

Ph

PPh2

PPh2

PPh2

PPh2

O

O

O

O

PPh2

PPh2

19 BINAP 20 H8-BINAP 21 SEGPHOS®

PPh2

PPh2

PPh2

PPh2

PPh2

PPh2

problem can be exacerbated if the alkene is notterminal. A screening exercise showed that theDiazaPhos-SPE diazaphospholane ligand system,22, was the best to prepare a bistetrahydrofuranwith good diastereoselectivity in the presence of arhodium-based catalyst, Scheme I.

Hans-Ulrich Blaser and Garrett Hoge (SolviasAG, Switzerland) gave a joint presentation. Blaserdescribed the extensive Solvias ligand families,mainly based on the ferrocene skeleton. New lig-ands that have been prepared and are currentlybeing evaluated are Kephos, 23, Fengphos, 24,Chenphos, 25, and Jospophos, 26. Hoge explainedhow Solvias performs ligand screenings and illus-trated the methodology with a number of practicalexamples including the reduction of acrylic acidsand ketones.

Professor Bernhard Breit (Albert-Ludwigs-Universität Freiburg, Germany) uses the conceptof self-assembly to prepare bisphosphine ligandsby dimerisation of monophosphines, such as 6-diphenylphosphinyl-2(1H)-pyridinone (6-DPPon),27. The dimeric ligand can be used to achieve highratios of linear products in the hydroformylationof terminal alkenes. Use of an organocatalyst such

as L-proline with an aldehyde and an alkene underhydroformylation conditions provides 1,3-diolswith good enantioselectivity. The self-assemblyconcept has been extended to chiral ligands inwhich the phosphorus moiety provides the asym-metry, such as 3-DMPICon, 28, and 3-BIPICon, 29.As with the reductions using DSM MonoPhosTM,the use of monodentate ligands allows for syner-gistic effects when two different ligands are usedin asymmetric hydrogenations.

Yongkui Sun (Merck & Co, Inc, U.S.A.)described some case studies on the use of asym-metric hydrogenations for drug synthesis atMerck. The final step in the synthesis ofsitagliptin, 30, is an asymmetric hydrogenation togive the β-amino amide. The use of a ferroceneligand has been superseded by the use of a ruthenium–DM-SEGPHOS® (SEGPHOS® withP(xyl)2 groups in place of PPh2) catalyst, with theβ-keto amide in the presence of ammonium salicylate as the amine donor. Examples of enzy-matic reactions, such as ketone reductions,


OH

O

O

OO

H

H

HO

1. Rh(CO)2(acac), Ligand

CO/H2

2. THF, HCl

(i) Rh(CO)2(acac), DiazaPhos-SPE

CO/ H2

(ii) THF, HCl

endo:exo = 10:1

α:β = 8:1

N

NP

O

O

N

NP

O

O

NH

O

Ph

O

HN

Ph

O

NH

Ph

HN

O

Ph

22 Bis(R,R,S)-DiazaPhos-SPE

Scheme IHydroformylationreaction to preparea bistetrahydrofuranin the presence of arhodium-basedcatalyst system withDiazaPhos-SPEligand

23 Kephos24 Fengphos

25 Chenphos 26 Jospophos

R2P Fe P

R2P Fe PR1

2

NMe2

PR2

Fe

PR2

P

R1

H

OFe

Fe

P

R1

NMe2

transaminations and the formation of cyanohy-drins were also given.

Professor Mikiko Sodeoka (RIKEN AdvancedScience Institute, Japan) described asymmetricreactions of metal enolates primarily based on theuse of palladium, with DM-SEGPHOS® as thechiral ligand. A wide range of reactions give highenantioselectivities including Michael, aldol,Mannich and α-fluorination reactions. For the lastclass of reactions, use of N-fluorobenzenesulfon-amide, (PhSO2)2NF, (NFSI) as the fluorinatingagent provides the best selectivity.

Concluding RemarksAs with the other meetings in this series,

NCCJapan 2009 was held just before CPhI Japan(5), allowing participants to attend both. There wassufficient time between lectures and at the banquetto allow for interaction between the participants,exhibitors and speakers. As noted above, a widevariety of methodology was covered, much associ-ated with the use of transition metal catalysis, and

in particular the use of pgm-based systems withphosphine ligands. As in the previous meetings,there was a good balance between the discovery ofnew methods and the industrial application ofexisting techniques. This conference seriesdeserves to continue to grow and prosper andProfessor Ikariya hinted that the next one mighthave the title Novel Chiral Chemistries Asia. I wishhim well with this endeavour and look forward toanother excellent meeting.


NH

Ph2P O

NH

O

P

NH

O

O

OP

R

R

27 6-DPPon

28 3-DMPICon

29 3-BIPICon (R = H)

F

F

FNH2

N

O

NN

N

30 Sitagliptin CF3

References1 Novel Chiral Chemistries Japan 2009 (NCCJapan)

Conference Programme: http://www.takasago-i.co.jp/news/2009/NCCJ2009_Program.pdf(Accessed on 27th July 2009)

2 D. J. Ager, Platinum Metals Rev., 2007, 51, (4), 1723 R. Noyori, Angew. Chem. Int. Ed., 2002, 41, (12), 20084 D. J. Ager, A. H. M. de Vries and J. G. de Vries,

Platinum Metals Rev., 2006, 50, (2), 545 CPhI Japan: http://www.cphijapan.com/eng/

(Accessed on 27th July 2009)

The ReviewerDavid Ager has a Ph.D. (University ofCambridge), and was a post-doctoralworker at the University ofSouthampton. He worked at Liverpooland Toledo (U.S.A.) universities;NutraSweet Company’s research anddevelopment group (as a MonsantoFellow), NSC Technologies, and GreatLakes Fine Chemicals (as a Fellow)responsible for developing newsynthetic methodology. David was then

a consultant on chiral and process chemistry. In 2002 he joinedDSM as the Competence Manager for homogeneous catalysis. InJanuary 2006 he became a Principal Scientist.

Early Attempts to Melt PlatinumBefore 1782 little more than a ‘partial agglomer-

ation’ of platinum had been achieved, mainly byhot forging from the powder which, although itsufficed to make many platinum artefacts, did notproduce homogeneous molten metal (1–3). Thefirst to melt impure platinum may have beenHenrik Theophil Scheffer (1710–1759) who in1751 melted platinum with copper, and laterarsenic, in a furnace (4). Franz Achard (1753–1821)similarly melted the metal with arsenic (5). In bothcases alloys of platinum, rather than pure platinum,are likely to have been melted. In 1775 PierreMacquer (1718–1784) and Antoine Baumé

(1724–1804) unsuccessfully attempted to meltplatinum in a porcelain crucible over a wood fire.Macquer and others (later including Lavoisier)then tried with burning glasses: a 56 cm diameterconcave mirror which focused the sun’s raysquickly melted iron but platinum gave only silvery-white glistening particles – the product probablycontained impurities of carbon which lowered itsmelting point (1). In 1774 a magnificent 1.2 mdiameter burning glass filled with alcohol wasmounted on a carriage and installed in the Jardinde l’Infante, Paris, France: it melted many materi-als, but not platinum (1, 6). An illustration of thisdevice is shown in Figure 1 (3).


Melting the Platinum Group MetalsFROM PRIESTLEY, LAVOISIER AND THEIR CONTEMPORARIES TO MODERN METHODS

By W. P. GriffithDepartment of Chemistry, Imperial College, London SW7 2AZ, U.K.; E-mail: [email protected]

Some fifty years ago Donald McDonald wrote in Platinum Metals Review on ‘The Historyof the Melting of Platinum’ (1) and Leslie B. Hunt marked the event’s bicentenary in ‘TheFirst Real Melting of Platinum: Lavoisier’s Ultimate Success with Oxygen’(2), which is alsocovered in the invaluable “A History of Platinum and its Allied Metals” (3). The topic isrevisited and extended here, showing how oxygen, first isolated by Joseph Priestley and CarlWilhelm Scheele, was used by Antoine Lavoisier to melt platinum. Work on the melting of theother platinum group metals (pgms) and modern methods for melting the metals are alsodiscussed.

DOI: 10.1595/147106709X472507

Fig. 1 The largeburning glass built forthe Académie Royaledes Sciences and used inan early attempt to meltplatinum (3)

Priestley, Scheele and the Discoveryof Oxygen

Joseph Priestley (1733–1804) was born inFieldhead, Birstall, near Leeds in the U.K., anddied in Philadelphia, U.S.A. He was better knownin the eighteenth century for his radical religiousand political beliefs; opposition to these and hisenthusiasm for the French Revolution led him toleave the U.K. in 1794. We remember him for hisscience: photosynthesis, optics, electrostatics,biology and physiology and above all chemistry(7). He discovered many new ‘airs’ – N2O, NO,NO2, CO, SO2, NH3 and SiF4 – and investigatedHCl, SO3, Cl2, PH3 and N2. He discovered oxygenon 1st August 1774, by heating mercuric oxide(HgO) with a burning glass, and showed that itsupported combustion (8–11). He called it‘dephlogisticated air’, believing in phlogiston, thealleged principle of combustion, to the end.Phlogiston features in one of his last papers,which also describes experiments on dissolvingplatinum in aqua regia (12). In October 1774, trav-elling in France with his patron the statesmanLord Shelburne, Priestley dined with Lavoisierand told him that he had obtained ‘a new kind ofair’ by heating HgO (11).

Carl Wilhelm Scheele (1742–1786), a Swedishpharmacist for whom chemistry was a rewardinghobby, rivals Priestley in the extent of his discov-eries. He was the first to isolate chlorine (in1774), HF and HCN, and did fundamental workon NH3, HCl, compounds of Ba, Mn, Mo, Ce, Pand on several organic compounds. He madeoxygen between 1773 and 1775 by heating MnO2,KNO3, HgO, HgCO3, MgNO3 or Ag2CO3, callingit ‘vitriol air’ (aer vitrolicus) or ‘fire air’ (aer nudus);he too was a phlogistonist until he died. Hispaper on oxygen was submitted in 1775 but notpublished until 1777 (13) so Priestley did notknow of his work. Lavoisier did know, however.On 12th April 1774, he sent two copies of his“Opuscules Physique et Chimique” to Stockholm witha copy for Scheele. In September 1774 Scheelewrote thanking him and told him how to make‘fire air’ from silver carbonate and a burningglass. His letter was rather vague and Lavoisierdid not reply (14).

Lavoisier, Oxygen and the Meltingof Platinum

Antoine Lavoisier (1743–1794) is a supremefigure in chemistry, a pivotal contribution beinghis refutation of the phlogistic theory (10, 15, 16).There is some controversy as to whetherLavoisier discovered oxygen independently (10,17, 18) – he was not averse to letting people thinkthis. However, in his paper on the melting of plat-inum (19) Lavoisier did grudgingly allude toPriestley’s priority: “...cet air, que M. Priestley a décou-vert à peu-près dans la même temps que moi, & je croimême avant moi…” (…this air, which M. Priestleydiscovered about the same time as I, and I believeeven before me…) – although some of his laterpublications omit the last phrase. Unlike Priestley,however, he began to understand the real signifi-cance of oxygen. In 1778 he refers to a principeoxygine (20), and in the first edition of the 1789edition of his textbook (21) – after melting plat-inum – he refers to oxygène, from οξυζ (acide) andγενηζ (j’engendre – ‘I beget’ or ‘I generate’). Hebelieved oxygen to be an element which was aconstituent of all acids.

Lavoisier’s Melting of PlatinumPriestley never attempted to melt platinum with

‘dephlogisticated air’ but the idea did occur to hisfriend, the Reverend John Michell (1724–1793),who wrote to him that “possibly platina might bemelted by it”, recollected by Priestley in his bookof 1775 (8) which Lavoisier may have read. InApril 1782 Lavoisier directed a stream of oxygenfrom his caisse pneumatique (a storage device capableof producing a stream of hydrogen, oxygen orboth, shown in Figure 2 (3)) onto hot hollowed-out charcoal containing powdered platinum. It isnot clear from his paper whether it was solely oxy-gen or a hydrogen-oxygen mixture: he had meansof producing and storing both gases. He reportedto the Académie des Sciences on 10th April 1782,that “...le platine est fondue complètement, et les petitsgrenailles se sont reunités en un globule parfaitementrond…” (...the platinum melts completely, and theparticles united in a perfectly round globule...) (19).

On 6th June 1782, Lavoisier demonstrated hisdiscovery at the Académie to a visiting Russian


nobleman. Benjamin Franklin (1706–1790), afriend and supporter of the often pennilessPriestley, was also present, writing to Priestleythat: “Yesterday the Count du Nord was at theAcademy of Sciences, when sundry Experimentswere exhibited for his Entertainment; amongthem, one by M. Lavoisier, to show that thestrongest Fire we yet know, is made in a Charcoalblown on with dephlogisticated air. In a Heat soproduced, he melted Platina presently, the Firebeing much more powerful than that of thestrongest burning mirror” (22), Figure 3 (3).

Although neither Lavoisier, Priestley norScheele could have realised it, the ability of oxygento support combustion, a process which emits the

degree of intense heat needed to melt platinum,arises largely from the intrinsic weakness of itsO–O bond (496 kJ mol–1) (23). This weakness andconsequent facile bond cleavage arises from elec-tron lone pair-lone pair repulsions between theatoms in the O2 molecule. The heat emitted from,for example, charcoal burning in an H2-O2 mixturearises from the formation of the much strongerC=O bonds in CO2 and O–H bonds in H2Owhich are the products of combustion.

Later Methods for Melting Platinumand the Other PGMs

Lavoisier’s method was not suited to large-scaleproduction of molten platinum. In 1816 William


Fig. 2 A drawing by Madame Marie Anne Paulze Lavoisier of the apparatus designed by Lavoisier to burn continuousstreams of oxygen and hydrogen (3)

Fig. 3 The concludingparagraph of BenjaminFranklin’s letter to Priestley,dated 7th June 1782, the dayafter Lavoisier demonstrated histechnique for melting platinumat the Académie (3)

Hyde Wollaston (3) wrote to the Cambridge mineralogist Edward Clarke (1769–1822), suggest-ing that he might try to melt iridium and thenative alloy osmiridium. Clarke used a blowpipewith an H2-O2 mixture. Despite several explo-sions he melted 0.5 ounces of the metal, writingthat it melted more quickly than did lead in a fire(24). He also melted palladium, rhodium, iridi-um and native osmiridium (25). Another earlyclaim was made for melting of rhodium by a‘hydro-pneumatic blow pipe’ (26). A differentapproach was to fuse the metal by placing itbetween the poles of a large voltaic battery.John Frederic Daniell (1790–1845), using seven-ty large copper/zinc-sulfuric acid cells in series,melted platinum, rhodium, iridium and nativeosmiridium (27).

The work of Henri Sainte-Claire Deville(1818–1881) and Jules Henri Debray (1827–1888)led the way to large-scale production of moltenplatinum. Their furnace used two large hollowed-out blocks of lime containing the metal, fired by acoal gas-oxygen mixture; the refractory limeabsorbed the slag formed by oxidation of basemetal impurities. They melted a 600 g sample ofplatinum in 1856 (28, 29), and this remained themethod of choice for melting platinum untilinduction furnaces became available in the earlytwentieth century.

In 1855 George Matthey (1825–1913) visitedthe Paris Exhibition of 1855 and there metDebray, who in 1857 offered him the British rightsfor his method for melting platinum. By 1861 theprocess was in commercial use by JohnsonMatthey and Company at Hatton Garden inLondon, U.K. In 1862 Deville came to London,and with Matthey melted a huge 100 kg ingot ofplatinum. The production of platinum, in thehands of Johnson Matthey, passed from a labora-

tory procedure to a full-scale operation, makingthe metal available worldwide.

Michael Faraday (1791–1867) tried but failedto persuade Deville to demonstrate his method atthe Royal Institution of Great Britain. Instead, inone of his last discourses there, entitled ‘OnPlatinum’, Faraday demonstrated its melting byusing a ‘voltaic battery’, mentioning that “if yougo into the workshops of Mr. Matthey [you will]see them hammering and welding away [at plat-inum]…”. He noted that five of the six pgms hadbeen melted, the exception being osmium. Hewrote that ruthenium has the highest meltingpoint, followed by iridium, rhodium, platinumand finally palladium (30). Faraday also referredto platinum in his celebrated “Chemical Historyof a Candle” (31).

Melting Points of the PGMsIt was not until the late nineteenth and early

twentieth centuries that reliable pyrometers weredevised for determining melting points (32, 33).Table I lists modern values for their melting andboiling points (34); osmium has the highest valuesfor both (35).

Current Methods for Melting thePGMs

Early methods for melting the pgms used blow-pipe procedures, while Daniell used electricity.These days the same basic procedures are stillused, albeit with newer techniques.

Oxy-hydrogen or oxy-propane blowpipes ortorches are still in use for bench-scale repair ofplatinum jewellery (36, 37), and certainly tempera-tures as high as 2500ºC and probably higher canbe reached.

Three principal methods, all electrical, are cur-rently used to melt the pgms for industrial use and


Table I

Melting and Boiling Points of the Platinum Group Metals (ºC) (34, 35)

Ru Rh Pd Os Ir Pt

m.p. 2333 1963 1555 3127 ± 50 2446 1768

b.p. 4319 ± 30 3841 ± 90 2990 ± 50 5303 ± 30 4625 ± 50 3876 ± 20

for large-scale jewellery manufacture (see Figure4). Induction heating, derived from Faraday’s dis-covery in 1831 (38) of electrical induction, useshigh-frequency alternating current passed througha water-cooled copper coil surrounding a refracto-ry crucible containing the metal sample. Electronbeam heating uses a refractory cathode, oftentungsten or molybdenum: the electrons from thisare accelerated in vacuo by a high-voltage direct cur-rent source to the metal (which becomes theanode) in a refractory container, the beam beingsteered by a magnetic field. Energies developedcan reach 150 keV, and material can be melted attemperatures above 2100ºC. Finally, in arc melt-ing, which can be traced back to Humphry Davy’searly experiments with a voltaic pile, the arc isstruck under argon between a tungsten cathodeand the metal which rests on a water-cooled cop-per anode. A direct current potential of 50 V to80 V and a current of several hundred amperes iscommonly used. The technique melts tungsten

(which has a melting point of 3422ºC), and so canmelt all six pgms. These methods have been welldescribed, although without reference to pgms(39), and there is a recent history of the inductionmethod (40).

For larger quantities of platinum or palladium(1 kg to 20 kg), induction heating is the quickestand most effective procedure. The metal charge isheld in alumina or zirconia crucibles and is typi-cally melted in air since oxidation is not a problemfor these metals. Graphite or copper alloy mouldsform the ingots and the molten metal is poured byan automated procedure.

For the higher-melting iridium and rhodium,induction heating is less suitable. For these, arcmelting is used for smaller quantities, usually lessthan 1 kg, and is effected in an inert gas atmos-phere with the charge held in a water-cooledcopper alloy mould. A tungsten cathode generatesand maintains the arc, which is moved over themetal to melt and consolidate it. Electron beam


Fig. 4 Industrial casting of molten platinum.Image courtesy of Johnson Matthey NobleMetals

melting is used to make larger ingots: an evacuat-ed chamber is used under a vacuum in excess of10–4 Torr, with the metal held in water-cooledcopper alloy moulds as for arc melting. As withthe latter technique, several melting sequences arerequired with the ingot being turned over severaltimes to ensure complete and even melting. Ingotsizes are typically between 2 kg and 15 kg (41).There is a recent paper in this Journal providinginformation on the melting of iridium (42).

ConclusionsThe discovery and production of gaseous oxy-

gen, by Scheele and Priestley, allowed the firstmelting of pure platinum by Lavoisier in the late

18th century. The other platinum group metalswere melted during the early 19th century, and bythe mid-19th century commercial-scale productionof platinum had become possible for the first time.The methods developed during this periodremained in use until the early 20th century, whenmodern methods of industrial scale productionusing electrical heating became possible.

Acknowledgements I am grateful to the editorial and technical staff

of Johnson Matthey for information on modernprocedures for melting the pgms, and to Dr MaxWhitby, Imperial College London, U.K., for gen-eral advice on these aspects.


1 D. McDonald, Platinum Metals Rev., 1958, 2, (2), 552 L. B. Hunt, Platinum Metals Rev., 1982, 26, (2), 793 D. McDonald and L. B. Hunt, “A History of Platinum

and its Allied Metals”, Johnson Matthey, London,U.K., 1982

4 H. T. Scheffer, Kungl. Vetensk. Akad. Handl., 1752, 13,269–276

5 F. K. Achard, Nouv. Mém. Acad. R. Sci. Berlin, 1781, 12,103

6 J. C. P. Trudaine de Montigny, P. J. Macquer, L. C.Cadet, A. Lavoisier and M. J. Brisson, Mém. Acad. R.Sci., 1774, 88, 62

7 “Joseph Priestley: A Celebration of His Life andLegacy”, eds. J. Birch and J. Lee, The Priestley Society,Birstall, South Yorkshire, U.K., 2007

8 J. Priestley, “The Discovery of Oxygen, Part 1”,Experiments by Joseph Priestly, LL.D. (1775);Alembic Club Reprints, No. 7, W. F. Clay, Edinburgh,1894, p. 8

9 W. P. Griffith, Notes Rec. R. Soc. Lond., 1983, 38, (1),1

10 W. H. Brock, “The Fontana History of Chemistry”,Fontana Press, London, U.K., 1992, 744 pp

11 J. Priestley, “The Doctrine of Phlogiston Established,and That of the Composition of Water Refuted”, 2ndEdn., Printed by Andrew Kennedy for P. Byrne,Philadelphia, U.S.A., 1803

12 J. Priestley, Trans. Am. Phil. Soc., 1802, 4, 113 C. W. Scheele, “Chemische Abhandlung von der Luft

und dem Feuer”, M. Swederus, Upsala and Leipzig,1777; ‘Chemical Treatise on Air and Fire’ in L. Dobbin(translated into English), “Collected Papers of CarlWilhelm Scheele”, G. Bell & Sons, Ltd, London, 1931;See also Alembic Club Reprints, No. 8, The AlembicClub, Edinburgh, 1906

14 U. Bocklund, ‘A Lost Letter from Scheele to Lavoisier’,Lychnos, 1957–58, 39

15 A. Lavoisier, Mém. Acad. R. Sci., 1775, 429 (issued in1778); Reprinted in “Œuvres de Lavoisier”, ImprimerieImpériale, Paris, 1862, Vol. 2, p. 122

16 A. Lavoisier, Mém. Acad. R. Sci., 1783, 505 (issued in1786); Reprinted in “Œuvres de Lavoisier”, ImprimerieImpériale, Paris, 1862, Vol. 2, p. 623

17 J. Priestley, “Experiments and Observations onDifferent Kinds of Air”, 2nd Edn., Printed for J.Johnson, London, U.K., 1784, Vol. 2, p. 34

18 S. J. French, J. Chem. Educ., 1950, 27, 83 19 A. Lavoisier, Mém. Acad. R. Sci., 1782, 457 (issued in

1785); Reprinted in “Œuvres de Lavoisier”, ImprimerieImpériale, Paris, France, 1862, Vol. 2, p. 423

20 A. Lavoisier, Mém. Acad. R. Sci., 1778, 535 (issued in1781); Reprinted in “Œuvres de Lavoisier”, ImprimerieImpériale, Paris, France, 1862, Vol. 2, p. 248

21 A. Lavoisier, “Traité Eléméntaire de Chimie”, 1st Edn.,Cuchet, Paris, France, 1789, Vol. 1, p. 48

22 “The Writings of Benjamin Franklin”, ed. A. H. Smyth,in 10 volumes, Macmillan, London, U.K., 1906, Vol.VIII, p. 453

23 H. M. Weiss, J. Chem. Educ., 2008, 85, (9), 121824 E. D. Clarke, Thomson’s Ann. Philos., 1817, 9, 8925 E. D. Clarke, “The Gas Blow-Pipe or, Art of Fusion

by Burning the Gaseous Constituents of Water”,printed by R. Watts for Cadell & Davies, London, 1819

26 J. Cloud, Trans. Am. Phil. Soc., 1818, 1, 16127 J. F. Daniell, Phil. Trans. R. Soc. Lond., 1839, 129, 8928 H. Sainte-Claire Deville, Ann. Chim. Phys., 1856, 46,

(3), 18229 H. Sainte-Claire Deville and H. J. Debray, Comptes

Rendus Acad. Sci., Paris, 1857, 44, 1101

References

30 M. Faraday, Chem. News, 1861, 3, 13631 M. Faraday, “A Course of Six Lectures on the

Chemical History of a Candle: to Which is Added aLecture on Platinum”, ed. W. Crookes, Griffin, Bohn,and Company, London, U.K., 1861, p. 173

32 H. L. Callendar, Philos. Mag., 1899, 47, 19133 Circular of the National Bureau of Standards, No. 7,

U.S. Department of Commerce, Washington, D.C.,U.S.A., 1910

34 J. W. Arblaster, Platinum Metals Rev., 2007, 51, (3), 13035 J. W. Arblaster, Platinum Metals Rev., 2005, 49, (4), 16636 Platinum Guild International, Technical Articles:

http://www.platinumguild.com/output/Page2414.asp

(Accessed on 21st July 2009)37 Platinum Guild International, Technical Videos:

http://www.platinumguild.com/output/Page1749.asp(Accessed on 21st July 2009)

38 M. Faraday, Phil. Trans. R. Soc. Lond., 1832, 122, 12539 A. C. Metaxas, “Foundations of Electroheat: A Unified

Approach”, John Wiley & Sons, Chichester, U.K.,1996

40 A. Mühlbauer, “History of Induction Heating andMelting”, Vulkan Verlag, Essen, Germany, 2008

41 Johnson Matthey Noble Metals, Private communication,20th March 2009

42 E. K. Ohriner, Platinum Metals Rev., 2008, 52, (3), 186


The AuthorBill Griffith is an Emeritus Professor ofChemistry at Imperial College, London,U.K. He has much experience with theplatinum group metals, particularlyruthenium and osmium. He haspublished over 270 research papers,many describing complexes of thesemetals as catalysts for specific organicoxidations. He has written seven bookson the platinum metals, and is

currently writing another on oxidation catalysis by rutheniumcomplexes. He is the Secretary of the Historical Group of theRoyal Society of Chemistry.

216

The need to move towards a low carbon econo-my has led to unprecedented interest in renewableenergy sources, including solar power. One type ofsolar cell, the dye sensitised solar cell (DSSC), firstreported in 1991 by Michael Grätzel and coworkersat the Ecole Polytechnique Fédérale de Lausanne(1), is a photoelectrochemical device which con-tains ruthenium in the photoanode and platinum inthe counter electrode. It therefore representsanother example of a platinum group metal-basedsustainable technology. In this review, DSSC tech-nology is briefly discussed to provide some contextfor selected examples of recent patent activity.

BackgroundHistorically, conventional solar cells have relied

on a solid semiconductor to perform the dual func-tion of light absorption and charge conduction,imposing strict requirements on the compositionand purity of materials used (2). DSSCs, by contrast, use a monolayer of photosensitive ruthe-nium-based dye adsorbed on a thin layer ofnanocrystalline titanium dioxide (TiO2) to harvestlight and, as a result, have comparatively low manufacturing costs. They can take the form ofthin, flexible and transparent sheets, making themuseful in applications such as building-integratedpower sources (3). Furthermore, they performeffectively in dim and diffuse light (1), allowing foruse indoors and in mobile electronic devices.

These advantages largely offset the lower effi-ciency of DSSCs, which stands at a record of 10%to 11% (3–5) – significantly lower than the 15% to18% achieved by the widely-used polycrystallinesilicon cell (6). Efforts are continually being under-taken to improve the efficiency and hence thecompetitiveness of the technology.

Overall cell efficiency is subject to a number offactors, but fundamental considerations relating tothe dye are: firstly, how efficiently the moleculesabsorb incident photons; secondly, how efficientlythese photons are converted to electron-hole pairs;

and thirdly, how effectively charge separation andcollection occurs (2). The most efficient DSSCsdemonstrated to date have all been based on ruthe-nium dyes developed by the Grätzel group: the N3,N719 and ‘black’ dyes (4) (Figure 1 (4, 7)). As wellas superior light harvesting properties and durabili-ty, a considerable advantage of these dyes lies in themetal-ligand charge transfer (MLCT) transition,through which the photoelectric charge is injectedinto the TiO2. For these ruthenium complexes, thistransfer takes place at a much faster rate than theback reaction, in which the electron recombineswith the oxidised dye molecule rather than flowingthrough the circuit and performing work (2).

Conversion efficiency of absorbed photons isalso very high, and offers little room for improve-ment (2, 8). Therefore, continued research effortsare largely focused on improving the absorptionof incident light. This can be achieved by manip-ulating the dye’s molecular structure to eitherincrease the degree of absorption of photons inthe functional wavelength range (as measured bythe molar extinction coefficient, ε), or to extendthe functional range – ideally, to within the nearinfrared (N-IR) region (9). Here, we have selectedthree patents, all claiming novel ruthenium com-plexes for application to DSSCs, to demonstratestrategies currently being investigated in this area.

Novel Ruthenium Dye ComplexesThe first example, filed by Dongjin Semichem

Co, Ltd, South Korea (7), claims a number of newcomplexes based on the N3 structure. The struc-ture has been altered by replacing one or both ofthe COOH groups on at least one of the bipyridylligands with a range of more highly π-conjugatedmoieties. The absorption spectra of six examples ofthe new complexes are presented, and the values ofε for three of the new dyes indicate a significantimprovement in absorption: in one embodiment ε = 22,640 M–1 cm–1 at 533 nm, compared to valuesof between 14,000 M–1 cm–1 and 15,000 M–1 cm–1 for


Progress in Ruthenium Complexes forDye Sensitised Solar Cells

DOI: 10.1595/147106709X475315 PGM HIGHLIGHTS

N3 and N719 at ~ 535 nm (8, 10). In two otherembodiments, ε values of ~ 21,000 M–1 cm–1 to22,500 M–1 cm–1 are achieved at wavelengths longerthan 550 nm, indicating a shift towards longerwavelengths. These improvements do not appearto translate into increased cell efficiency and valuesgiven for short-circuit current density (Jsc) andopen circuit voltage (Voc) are lower than for theestablished dye. However, an interesting point tonote is the possibility of using a combination ofdyes, an approach which may allow greater flexibil-ity in optimising both absorption and range.

An application filed by Turkiye Sise ve CamFabrikalari AS, Turkey (11), aims in one embodi-

ment to increase ε through extended π-conjugationand a double core. A ruthenium dimer structure isclaimed, designated K20 (Figure 2) and described ashaving ε = 22,000 M–1 cm–1. The wavelength at whichthis measurement is taken is not given, although else-where the authors show that the longest-wavelengthabsorption peak occurs at 520 nm. This ε value isagain higher than values for N3 and N719 at similarwavelengths. Overall efficiency is also good, beingcomparable to the existing dyes.

The technique of increasing conjugationthrough the use of larger and more complex lig-ands is again demonstrated by a patent granted in2009 to inventors from Everlight Chemical


Ru

NN

C

S C

S

N

N

N

N

HOOC

COOH

COOH

COOH

N3 dye

Ru

NN

C

S C

S

N N

N

TBAOOC

COOH

COOTBA

N

C

S

Black dye

Ru

NN

C

S C

S

N

N

N

N

HOOC

COOTBA

COOH

COOTBA

N719 dye

Fig. 1 Structures of the ruthenium-based dyes N3, N719 and ‘black dye’ developed by the Grätzel group (4, 7)

Fig. 2 Structure of a novel ruthenium dimer dye complex (11)

Ru

NN

C

S C

S

N

N

N

HOOC

COOH

Ru

N

C

S

N

N

N

N

COOH

COOH

C

S

N

N

N

H3C

H3C

N

CH3

CH3

K20

TBA = tetrabutylammonium cation

Industrial Corp (U.S.A.) and Academia Sinica inTaiwan (12). The complexes claimed here are alsobased on N3, with one of the ligands modified toa structure with additional aromatic rings and, insome embodiments, containing alkyl chains. Theinventors present the results of comparative testsof one of the complexes (shown in Figure 3)against N719: at the longest peak wavelength (~ 530 nm), ε is increased to 14,007 M–1 cm–1

(from 12,617 M–1 cm–1 quoted for N719) and aslight redshift in the absorption spectrum is seen.The values claimed for Jsc and Voc are very similarto those achieved using N719, and the overall cellefficiency is also comparable to the existing dyes.

Concluding RemarksIt is clear that research into dyes for DSSCs is

progressing and new ruthenium-based structurescontinue to be reported. Although alternative dyeshave been developed, including non-metal organ-ic dyes (13) and dyes based on iron and zinc (14,15), these have so far proved inferior to the ruthe-nium dyes (4). Dyes formulated from platinumand iridium complexes are also showing somepromise (16, 17), but this research is still in theearly stages. With this in mind, the most promis-ing current strategy is to increase the efficiency oflight absorption at the molecular level by modify-ing or enhancing the established ruthenium-baseddyes, which still hold their place at the forefront ofthe technology. The improved light absorption

achieved in the patents discussed here holdspromise for increased cell efficiency, which maybe realised with further refinements. With DSSCsnow at the pilot scale and seeing increasing commercial investment (18–21), developments inthis area will be watched with interest.

M. RYAN

References1 B. O’Regan and M. Grätzel, Nature, 1991, 353, (6346), 7372 M. Grätzel, Platinum Metals Rev., 1994, 38, (4), 1513 M. Grätzel, Innovation, 2007, 7, (3), cover story4 Z. Jin, H. Masuda, N. Yamanaka, M. Minami, T.

Nakamura and Y. Nishikitani, J. Phys. Chem. C, 2009,113, (6), 2618

5 Md. K. Nazeeruddin, P. Péchy, T. Renouard, S. M.Zakeeruddin, R. Humphry-Baker, P. Comte, P. Liska,L. Cevey, E. Costa, V. Shklover, L. Spiccia, G. B.Deacon, C. A. Bignozzi and M. Grätzel, J. Am. Chem.Soc., 2001, 123, (8), 1613

6 K. Bullis, ‘More Efficient, and Cheaper, Solar Cells’,Technology Review, MIT, U.S.A., 14th September 2009:http://www.technologyreview.com/energy/23459/

7 H. Bae, C. Lee, J. Baek and H. Yang, DongjinSemichem Co Ltd, ‘Novel Ru-Type Sensitizers andMethod of Preparing the Same’, World Appl.2009/082,163

8 M. K. Nazeeruddin, A. Kay, I. Rodicio, R. Humphry-Baker, E. Müller, P. Liska, N. Vlachopoulos and M.Grätzel, J. Am. Chem. Soc., 1993, 115, (14), 6382

9 Y. Liu, H. Shen and Y. Deng, Front. Mater. Sci. China,2007, 1, (3), 293

10 Md. K. Nazeeruddin, S. M. Zakeeruddin, R. Humphry-Baker, M. Jirousek, P. Liska, N. Vlachopoulos, V.Shklover, C.-H. Fischer and M. Grätzel, Inorg. Chem.,1999, 38, (26), 6298

11 S. Icli, C. Zafer, K. Ocakoglu, C. Karapire, B. Yoldas,Y. Teoman and B. Kuban, Turkiye Sise ve CamFabrikalari AS, ‘Novel Ruthenium Complex Photo-Sensitizers for Dye Sensitized Solar Cells’, World Appl.2009/078,823

12 J.-T. Lin, Y.-C. Hsu, Y.-S. Yen and T.-C. Yin, EverlightUSA, Inc and Academia Sinica, ‘Ruthenium Complex’,U.S. Patent 7,538,217; 2009

13 K.-J. Jiang, K. Manseki, Y. Yu, N. Masaki, J.-B. Xia,L.-M. Yang, Y. Song and S. Yanagida, New J. Chem.,2009, 33, (9), 1973

14 S. Ferrere, Inorg. Chim. Acta, 2002, 329, (1), 7915 Q. Wang, W. M. Campbell, E. E. Bonfantani, K. W.

Jolley, D. L. Officer, P. J. Walsh, K. Gordon, R.Humphry-Baker, Md. K. Nazeeruddin and M. Grätzel,J. Phys. Chem. B, 2005, 109, (32), 15397

16 E. A. M. Geary, L. J. Yellowlees, L. A. Jack, I. D. H.Oswald, S. Parsons, N. Hirata, J. R. Durrant and N.Robertson, Inorg. Chem., 2005, 44, (2), 242

17 E. Baranoff, J.-H. Yum, M. Grätzel and Md. K.Nazeeruddin, J. Organomet. Chem., 2009, 694, (17), 2661

18 Dyesol: http://www.dyesol.com/19 G24 Innovations: http://www.g24i.com/20 3GSolar Ltd, Solar Energy Modules: http://3gsolar.com/21 Solaronix SA: http://www.solaronix.com/


Ru

NN

C

S C

S

N

N

N

N

HOOC

COOH

Fig. 3 A modified complex based on the ruthenium dyeN3 (12)

“PEM Fuel Cell Electrocatalysts and CatalystLayers: Fundamentals and Applications”, edited byJiujun Zhang, is an excellent book. The editor is anexperienced electrochemist with twenty-four yearsof experience, nine in fuel cells, and is theTechnical Leader in Catalysis at the NationalResearch Council Institute for Fuel Cell Innovationin Canada. Zhang states in his introduction that acomprehensive and in-depth book that focuses onboth fundamental and application aspects of polymer electrolyte membrane (PEM) fuel cellelectrocatalysts and catalyst layers is definitelyneeded. I agree, PEM fuel cells have made majoradvances in recent years, and have begun to entertheir eagerly-anticipated commercialisation phase(1). However, this has brought new challenges,requiring electrochemists to work much moreclosely with engineers to optimise systems for specific applications. Therefore I read this bookeagerly, hoping that the authors had managed towrite a fundamental electrochemistry book thatwas readable by an informed engineer. I believethey have succeeded in this, and in this shortreview I have discussed a few key points whichshould illustrate this.

The book is split into useful chapters, a numberof them identifying and discussing mitigationstrategies for some of the most significant barriersremaining to the wider adoption of PEM fuel cells, such as Chapter 17 on ‘Reversal-tolerantCatalyst Layers’. Other chapters introduce more fundamental electrochemical concepts such asadsorption, activation energies and thermodynam-

ics, which are discussed in Chapter 5, ‘Applicationof First Principles Methods in the Study of FuelCell Air-Cathode Electrocatalysis’.

The level of thoroughness and detail is alsoimpressive: for example, Chapter 16 on ‘CO-toler-ant Catalysts’ alone has almost 450 references. Thischapter describes both the fundamental conceptsand reaction mechanisms necessary to understandthe problem of carbon monoxide ‘poisoning’ offuel cell catalysts – in particular the bifunctionalmechanism of carbon monoxide tolerance exhib-ited by platinum-ruthenium alloy catalysts, whereruthenium provides the ability to generatehydroxyl species to oxidise CO at lower potentials(2). The chapter then goes on to discuss the devel-opment of other carbon monoxide-tolerantcatalysts, describing the vast array of mostly plat-inum-based catalysts that have been developedover the last thirty to forty years (3, 4). Crucially,each chapter ends in a brief but useful conclusionwhich identifies the avenues of research where weshould anticipate future breakthroughs. The refer-ences are conveniently located at the end of eachchapter, making them easy to access. Each chaptercan be read as a stand-alone piece.

The book claims to be aimed at the broader fuelcell community, including engineers, industryresearchers and students. I would agree with thisclaim, but with the small caveat that I would notrecommend it to a total novice, as the level ofdetail would rapidly become overwhelming forsomeone not familiar with the language and concepts associated with fuel cells and electro-


“PEM Fuel Cell Electrocatalysts andCatalyst Layers: Fundamentals andApplications”EDITED BY J. ZHANG (NRC Institute for Fuel Cell Innovation, Canada), Springer-Verlag London Ltd, Guildford, Surrey, U.K., 2008,

1137 pages, ISBN 978-1-84800-935-6, £121.50, €134.95, U.S.$209.00 (Print version); e-ISBN 978-1-84800-936-3,

DOI: 10.1007/978-1-84800-936-3 (Online version)

Reviewed by Gregory J. OfferDepartment of Earth Science and Engineering, South Kensington Campus, Imperial College, London SW7 2AZ, U.K.;

E-mail: [email protected]

DOI: 10.1595/147106709X474361

chemistry. The book is clearly up to date and rep-resents a considerable amount of work by theauthors, who all appear well qualified to writetheir respective chapters. The subject area of eachchapter would merit an entire book in that fieldalone – but these exist already, and the value hereis in linking the subject areas together so that the reader can benefit from having them all in one volume. The end result is rather long at over 1100pages, but this is necessary and not a criticism,and represents good value considering the listprice.

For the reader who is interested in platinumgroup metals (pgms) this book contains plenty ofinformation. Nearly every chapter discusses anarea that is dominated by the electrochemistry ofplatinum and other pgms, but this is not surprisingconsidering the central role of platinum in PEMfuel cell catalysis. From this point of view, thebook also provides a good review of current tech-nology and does not appear to make any majoromissions of information that the pgm catalystspecialist would be expecting to see.

On the whole I got a very positive impressionof this book, and feel that it does succeed in itsaims. It is well written and sufficiently consistentin style considering its multiple authors, and theeditor has done a good job of pulling together somany topics and presenting them as a coherentwhole. The book would be a good purchase for

anyone who has an interest in the science of PEMfuel cells. If you are new to the field, perhaps anundergraduate, there are probably better books tostart with (see for example (5)). However, if youare a scientist or engineer, either at the top of yourfield or with just a year or more of experience inelectrochemistry and/or electrocatalysis, this is aworthy addition to your book collection.


The ReviewerDr Gregory Offer is a Research Associate inFuel Cell Science and Engineering, within theFaculty of Engineering at Imperial College,London, U.K., working with both theDepartment of Earth Science Engineering andthe Department of Materials. He is also projectmanager of Imperial Racing Green, anundergraduate teaching project buildinghydrogen-powered fuel cell hybrid vehicles.

He is currently on secondment to the Energy and Climate ChangeCommittee at the Houses of Parliament in London, U.K.

References1 “Fuel Cells: Commercialisation”, Fuel Cell Today,

U.K., 2008:http://www.fuelcelltoday.com/events/industry-review(Accessed on 14th August 2009)

2 A. R. Kucernak and G. J. Offer, Phys. Chem. Chem. Phys.,2008, 10, (25), 3699

3 O. A. Petry, B. I. Podlovchenko, A. N. Frumkin andH. Lal, J. Electroanal. Chem., 1965, 10, (4), 253

4 J. S. Spendelow, P. K. Babu and A. Wieckowski, Curr.Opinion Solid State Mater. Sci., 2005, 9, (1–2), 37

5 R. O’Hayre, S.-W. Cha, W. Colella and F. B. Prinz,“Fuel Cell Fundamentals”, 2nd Edn., John Wiley &Sons, Inc, New York, U.S.A., 2009, 576 pp

221

The Taylor Conferences are organised by theSurface Reactivity and Catalysis (SURCAT) Groupof the Royal Society of Chemistry in the U.K. (1).The series began in 1996, to provide a forum fordiscussion of the current issues in heterogeneouscatalysis and, equally importantly, to promoteinterest in this field among recent graduates. Thefourth in the series was held at Cardiff Universityin the U.K. from 22nd to 25th June 2009, attract-ing 120 delegates, mainly from U.K. academiccentres specialising in catalysis. Abstracts of all lec-tures given at the conference are available on theconference website (2). The first half of the confer-ence consisted of presentations by establishedresearchers from the U.K., Japan and the U.S.A.,with each presentation afforded ample time fordebate and discussion. The format of the secondhalf was similar, but with a key difference: the pre-senters were some of the postgraduate studentsand postdoctoral researchers who, it is hoped, willbecome the future generation of catalysis experts.

Concepts, Theories and MethodologyProfessor Sir Hugh Taylor, after whom the

Taylor conferences are named, was a pioneer inthe study of chemisorption and catalysis on metalsand metal oxides (3). As Professor Frank Stone(Emeritus Professor of Chemistry, University ofBath, U.K.) reminded us in his opening address, H. S. Taylor (as he was known in his time) wasresponsible for introducing the concepts of acti-vated adsorption and of the active site, both ofwhich were highly controversial when he first proposed them around 1930 (4), but which havebecome fundamental to our understanding ofmany catalytic phenomena.

Professor Gabor Somorjai (University ofCalifornia, Berkeley, U.S.A.) developed the themethat progress in catalysis is stimulated by revolu-tionary changes in thinking. He predicted that,whereas in previous eras new catalysts were identi-fied through an Edisonian approach (based on trialand error) or discovered on the basis of empiricalunderstanding, future catalyst design will be basedon the principles of nanoscience. He highlighted hisidea of ‘hot electrons’ that are ejected from a metalby the heat of reaction produced at active sites, butwhich could become a potential energy source ifthey were generated by the absorption of light.

As described by Professor Richard Catlow(University College London, U.K.) and StephenJenkins (University of Cambridge, U.K.), quantummechanical techniques for modelling many-electron systems lend themselves to the study ofcatalytic materials and catalytic reaction pathways.Professor Catlow’s particular expertise lies in thestudy of defective metal oxides, and the way inwhich they interact with metal particles. In the caseof palladium deposited on ceria, his models predictan increase in the concentration of Ce3+ speciesresulting from electron transfer from the metal tothe metal oxide. Jenkins has been examining thelikelihood of specific reaction steps taking place onthe surface of supported metal catalysts. For bothalkane synthesis and combustion, his calculationsimplicate a common formyl intermediate, which isnot readily detected by spectroscopic techniques.However, Professor Charles Campbell (Universityof Washington, U.S.A.) cautioned against an over-reliance on surface modelling. Based on classicalmicrocalorimetric measurements, he has shownthat density functional theory (DFT) underpredicts


The Taylor Conference 2009CONVERGENCE BETWEEN RESEARCH AND INNOVATION IN CATALYSIS

Reviewed by S. E. Golunski§ and A. P. E. York*‡

Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.;

and ‡Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street,

Cambridge CB2 3RA, U.K.; *E-mail: [email protected]

DOI: 10.1595/147106709X474307

§Present address: Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.

the heat of adsorption for a variety of molecules(for example, carbon monoxide, cyclohexene andaromatics) on a range of surfaces (such as carbon,precious metals or metal oxides).

Taking a View Professor Lynn Gladden (University of

Cambridge) described how macroscopic andmicroscopic events can be tracked in an opticallyopaque system, such as a catalytic reactor. Usingmagnetic resonance imaging (MRI) – essentially thesame technique as used diagnostically in medicine –she has been able to observe the liquid flow fieldsthat develop in packed bed reactors. By combiningthe images with measurements from temperaturesensors, detailed reaction profiles can be producedfor steady-state and dynamic operating conditions.

On a different scale, Professor Chris Kiely(Lehigh University, U.S.A.) has used dark-fieldimaging techniques to detect the smallest metallic,bimetallic and metal oxide particles (less than 1 nmin diameter) by electron microscopy. In what maybecome a seminal study, he has correlated the highCO-oxidation activity of a specific gold/iron oxide(Au/Fe2O3) catalyst with the presence of two-layer, 0.5 nm-diameter gold clusters.

The importance of studying catalysis over arange of scales was emphasised by ProfessorTrevor Rayment (Diamond Light Source Ltd,U.K.). The new U.K. synchrotron light source isintended to provide understanding of ‘real catalysts, under real conditions, in real time’ (5).One of the ambitions is to increase the through-put for techniques such as X-ray absorptionspectroscopy, by reducing the amount of non-productive beam time. Although the Diamondfacilities are not expected to provide the tools forcatalyst discovery, it is hoped that they can accel-erate the development process by identifying thecritical relationships between catalyst structureand performance.

Controlling SelectivityStressing a point made by Professor Somorjai

that catalysis in the 21st century is all about selec-tivity, Chris Baddeley (University of St Andrews,U.K.) and Professor Andrew Gellman (Carnegie

Mellon University, U.S.A.) separately describedthe complex dependence of enantioselective reac-tions on surface composition and structure. As explained by Professor James Anderson(University of Aberdeen, U.K.), in the context ofalkyne hydrogenation, poor selectivity is often theresult of heterogeneity in the exposed sites, evenon apparently clean and compositionally homoge-neous surfaces. Through targeted use of additives,such as bismuth in the case of palladium-basedhydrogenation catalysts, specific non-selectivesites can be deliberately blocked.

During the direct synthesis of hydrogen perox-ide from hydrogen and oxygen, the combustion ofhydrogen and the over-hydrogenation of hydrogenperoxide to water need to be suppressed.Professor Graham Hutchings (Cardiff University,U.K.) has shown that gold-palladium catalysts areamong the most effective, but their performancecan be sensitive to the support material used. Incollaboration with Professor Kiely, he has foundthat the nature of the dispersed gold-palladium canvary, with core-shell particles (on titania and alumina) producing lower yields of H2O2 than palladium-rich alloy particles (on carbon). Bothtypes of core-shell particle, those with a gold coreand palladium shell and those with a palladium coreand gold shell, were less active than the palladium-gold alloy.

Professor Masatake Haruta (Tokyo Metropoli-tan University, Japan) has found that small goldclusters can selectively catalyse some particularlychallenging reactions. The outstanding example isthe selective insertion of oxygen into propylene toform propylene oxide, which is currently producedby indirect processes that produce large quantitiesof waste byproducts. By reactively grinding a non-chloride Au(III) precursor with titanium silicalite(TS-1), Professor Haruta has dispersed the gold as1.6 nm particles, which can activate propylene toreact with O–O–H species formed from oxygenand water at the metal-support interface.

Promoting and Maintaining ActivityVanadia supported on θ-alumina is one of the

best catalysts for butane dehydrogenation, but therate of reaction is very sensitive to the vanadia


loading. Professor David Jackson (University ofGlasgow, U.K.) reported that maximum activitycoincides with the presence of a mainly polymericform of vanadate species which covers most of thealumina surface. However, another key perfor-mance criterion is durability. During butanedehydrogenation, two forms of deactivation canbe discerned: a short-term but reversible effectcaused by deposition of carbon-rich species onthe catalyst surface, and a longer-term effect asso-ciated with an irreversible phase change in thealumina.

In the Francois Gault Lecture, ProfessorRobbie Burch (Queen’s University Belfast, U.K.)explained the challenges faced in developing andstudying catalyst technology for removing nitro-gen oxides (NOx) from diesel exhaust. Focusingon the use of silver for NOx reduction by directreaction with some of the diesel fuel, he showedthat its performance can be dramatically improvedby the addition of hydrogen. As described in a presentation by Stan Golunski (Johnson MattheyTechnology Centre, Sonning Common, U.K.) thehydrogen can be generated in situ through aprocess of exhaust gas reforming using a rhodiumcatalyst. Professor Burch explained how X-rayabsorption fine structure (EXAFS) studies of silver have been used to refute one of the pro-posed roles of hydrogen, as a structural modifier,implying instead that it is directly involved in theNOx-reduction mechanism. Although severalspectroscopic studies have been published (6)showing the presence of cyanide and isocyanateon the silver surface when hydrogen is present,kinetic measurements at Queen’s University Belfasthave ruled these out as reactive intermediates, suggesting that more transitory species (such ashydroxamic acid or ammonia) are involved.

Future ProspectsDuring his introduction to the postgraduate

student and postdoctoral researcher presentations,Jack Frost (Johnson Matthey Fuel Cells, U.K.)compared and contrasted the academic process ofresearch with the industrial activity of innovation.He used the example of vehicle emission controlto show how the pressing need for improved local

air quality led to the development of technologyfor catalytic aftertreatment using pgm catalysts (7).This highly effective technology does not, howev-er, address the global problem of greenhouse gasemissions, which is now the prime motivator forthe introduction of fuel cells.

Appropriately, there was an environmentaltheme running through many of the presentationsin this section of the conference. For example, COoxidation was covered by SankaranarayananNagarajan (National Chemical Laboratory, Pune,India), who looked at oxygen mobility and the roleof subsurface oxygen on palladium surfaces (8, 9),Figure 1. The subject was also covered by KevinMorgan (Queen’s University Belfast), who present-ed a temporal analysis of products (TAP) studyshowing that the addition of gold to CuMnOx

results in the availability of more surface oxygenand promotion of the Mars-van Krevelen oxygentransfer mechanism.

A number of researchers from CardiffUniversity presented work on selective oxidationreactions. For example, Jonathan Counsell has beenstudying the effect of adding gold to a supportedpalladium acetoxylation catalyst. He has foundthat the gold suppresses carbon formation on thepalladium surface by preventing dehydrogenation.Kara Howard described her work on modellingoxygen dissociation on gold clusters supported on iron oxide, and showed that the iron oxide stabilises dissociated oxygen atoms. DyfanEdwards presented a surface science study of thesynergy between the individual metal oxides iniron molybdate catalysts, which are used for oxi-dising methanol to formaldehyde. The selectivityof iron oxide changes with the level of coverageby molybdenum, from total combustion when nomolybdenum is present, to partial oxidation (toCO) at low coverage, and finally selective oxida-tion (via a methoxy intermediate) at high coverage.Dr Jennifer Edwards has been examining theeffect of preparation and pretreatment variableson the performance of gold-palladium catalystsfor the direct synthesis of hydrogen peroxide.Acid pretreatment of the support material hasresulted in catalysts with lower activity for theunwanted consecutive hydrogen peroxide-hydro-


genation reaction, leading to very impressivehydrogen peroxide yields.

The influence of the iron:cobalt ratio in anFe2O3-Co3O4 catalyst, for converting ethanol tohydrogen, has been studied by Abel Abdelkader(Queen’s University Belfast). Fe2O3 catalysesethanol steam reforming, and Co3O4 the water-gasshift reaction, so that a 1:1 ratio produces the opti-mum yield. In the field of syngas and hydrogenutilisation, Poobalasuntharam Iyngaran (Universityof Cambridge) presented a study of the effect ofpotassium promoters on ammonia synthesis overiron, which showed that stepwise hydrogenationof nitrogen surface adatoms is unaffected by thepresence of potassium. Sharon Booyens (CardiffUniversity) is interested in DFT modelling of COadsorption on iron surfaces, in the context ofFischer-Tropsch catalysis. The models predictthat surface carbon causes a weakening of theFe–CO interaction, and therefore CO dissociationbecomes less favourable. Andrew McFarlane(University of Glasgow) presented his work on C5 olefin hydrogenation over 1% Pd/Al2O3. Hesuggested that reaction of the cis-pentene isomermust proceed via formation of the trans isomerbefore hydrogenation can occur.

Finally, there were several very topical presenta-tions concerned with clean synthesis of chemicalsand fuels. Lee Dingwall (University of York, U.K.)has been synthesising and working with a bifunc-tional heterogeneous catalyst that combines anactive ruthenium organometallic centre with apolyoxometallate cage, Figure 2. This provides acidsites and also confers great stability, and the cata-lyst structure displays high activity for C–C bondformation. Ceri Hammond (Cardiff University)described the reaction of glycerol with urea overzinc, gallium or gold supported on zeolite.Glycerol carbonate can be obtained with highselectivity in a one-step solvent-free process overthese catalysts, though there is some question overtheir stability.

The prize for the best student presentation wasawarded to Janine Montero (University of York)who is researching the use of heterogeneous catalysts for biodiesel synthesis by transesterifica-tion, as a replacement for the liquid catalystscurrently in use. She has shown, by Auger electronspectroscopy, that high-temperature calcination of nanoparticulate magnesium oxide results inincreased surface polarisability, and therefore higherLewis basicity. Her results show that there is a


Fig. 1 Schematic model for oxygen diffusion followed by CO + O2 reaction on Pd(111) > 550 K. Pdδ+= mildly oxidised Pd(Courtesy of Chinnakonda S. Gopinath, National Chemical Laboratory, Pune, India)

CO

O2

4

6

2

CO2

1

5

3

Pd(111)

Pdδδ+(111)

Pdδδ+(111)

Pd(111)

Pdδδ+(111)

Pdδδ+(111)

linear relationship between polarisability and trans-esterification activity over these MgO catalysts.

SummaryIn summing up the conference, Professor

Wyn Roberts (Emeritus Professor, CardiffUniversity) recalled that when he began his Ph.D.he had to make the choice between studyingclean surfaces (i.e. single crystals) or real catalysts.As many of the presentations highlighted, thisdistinction is no longer useful, with the so-called‘material’ and ‘pressure’ gaps in catalysis, betweenresults obtained from surface science studies,usually using idealised surfaces under high

vacuum, and those from real catalyst materials atambient or high pressures (10), having graduallynarrowed. Frost had earlier commented on a sim-ilar convergence, between research andinnovation. As he pointed out, though, theseactivities need to remain distinct, because theyfulfil quite different functions. However, withtheir shared values of insight, integrity, creativityand professionalism, they will be increasinglydirected in parallel at our most urgent challengesin catalysis and in society: sustainability and envi-ronmental protection.

The fifth Taylor Conference is scheduled totake place in Aberdeen in 2013 (11).


+ -

HNEt 3

HNEt3

P

Ru C

P

WO

Fig. 2 Proposed structure of thepolyoxometallate-tethered rutheniumcomplex [HNEt3]+[(Ru{η5-C5H5}{PPh3}2)2(PW12O40)]–(Courtesy of Karen Wilson, University ofYork, U.K.)

1 Royal Society of Chemistry, Surface Reactivity andCatalysis (SURCAT) Group: http://www.rsc.org/Membership/Networking/InterestGroups/SurfaceReactivity/index.asp (Accessed on 5th August 2009)

2 The Taylor Conference 2009: http://www.taylor.cf.ac.uk/ (Accessed on 5th August 2009)

3 E. R. Rideal and H. S. Taylor, “Catalysis in Theory andPractice”, Macmillan and Co Ltd, London, U.K., 1919

4 P. B. Weisz, Microporous Mesoporous Mater., 2000, 35–36,1

5 Diamond Light Source, Publications, Case Studies:http://www.diamond.ac.uk/Home/Publications/case_studies.html (Accessed on 27th August 2009)

6 F. Thibault-Starzyk, E. Seguin, S. Thomas, M. Daturi,H. Arnolds and D. A. King, Science, 2009, 324, (5930),1048

7 M. V. Twigg, Appl. Catal. B: Environ., 2007, 70, (1–4),2

8 C. S. Gopinath, K. Thirunavukkarasu and S. Nagarajan,Chem. Asian J., 2009, 4, (1), 74

9 S. Nagarajan, K. Thirunavukkarasu and C. S. Gopinath,J. Phys. Chem. C, 2009, 113, (17), 7385

10 J. M. Thomas, J. Chem. Phys., 2008, 128, (18), 18250211 Royal Society of Chemistry, Publishing, Journals,

PCCP, News, 2009: http://www.rsc.org/Publishing/Journals/CP/News/2009/TaylorPCCPPrizes.asp(Accessed on 5th August 2009)

Stan Golunski has recently been appointedDeputy Director of the Cardiff CatalysisInstitute; he was formerly TechnologyManager of Gas Phase Catalysis at theJohnson Matthey Technology Centre atSonning Common in the U.K. His researchinterests include catalytic aftertreatmentand reforming.

References

Andy York is a Johnson Matthey ResearchFellow in the Department of ChemicalEngineering and Biotechnology at theUniversity of Cambridge, U.K. Hisresearch interests lie at the interfacebetween catalyst chemistry and reactionengineering.

The Reviewers

CATALYSIS – APPLIED AND PHYSICAL ASPECTSCatalytically Active, Magnetically Separable, andWater-Soluble FePt Nanoparticles Modified withCyclodextrin for Aqueous Hydrogenation ReactionsK. MORI, N. YOSHIOKA, Y. KONDO, T. TAKEUCHI and H.YAMASHITA, Green Chem., 2009, 11, (9), 1337–1342

Thermal decomposition of Fe(CO)5, followed byreduction of Pt(acac)2 in the presence of oleic acidand oleylamine, gave FePt nanoparticles (1) with Fe-rich cores and Pt-rich shells. (1) were subsequentlytreated with γ-cyclodextrin (γ-CD). FePt-γ-CD (2)exhibited superparamagnetic behaviour at 300 K. (2)was used for aqueous hydrogenation reactions, witheasy recovery of (2) by applying an external magnet.

Catalytic Inactivation of Bacteria Using Pd-Modified TitaniaL. R. QUISENBERRY, L. H. LOETSCHER and J. E. BOYD, Catal.Commun., 2009, 10, (10), 1417–1422

For the photocatalytic sterilisation of Escherichia coliin H2O, Pd/TiO2 was faster than Pt/TiO2. Pd/TiO2

was also active in the absence of light. Pd/TiO2 tem-porarily lost bactericidal activity after use, but wasreactivated in air. It is proposed that the Pd metal onthe surface of Pd/TiO2 is reduced in solution duringthe reaction, and must be reoxidised to regain activity.The reduction may initiate the bactericidal activity.

CATALYSIS – REACTIONSIridium Catalysed Alkylation of 4-HydroxyCoumarin, 4-Hydroxy-2-quinolones and Quinolin-4(1H)-one with Alcohols under Solvent FreeThermal ConditionsR. GRIGG, S. WHITNEY, V. SRIDHARAN, A. KEEP and A.DERRICK, Tetrahedron, 2009, 65, (36), 7468–7473

Ir-catalysed alkylation of the title compounds withsubstituted benzyl and aliphatic alcohols under solvent-free heating gave the monoalkylated products in highto excellent yield. 3,3'-Bis (heterocyclyl) methane prod-ucts can arise via a Michael addition pathway. Thealkylation of 4-hydroxy-1-methyl-2(1H)-quinoline withBzOH, KOH and the Ir chloro-bridged [Cp*IrCl2]2

dimer was carried out at 110ºC for 48 h in a sealed tube.

An Alternative Synthesis of Tamiflu®: A SyntheticChallenge and the Identification of a Ruthenium-Catalyzed Dihydroxylation RouteK. YAMATSUGU, M. KANAI and M. SHIBASAKI, Tetrahedron,2009, 65, (31), 6017–6024

A Ru-catalyzed dihydroxylation synthetic route wasidentified for Tamiflu®, which removes the need fora Mitsunobu inversion step. Only 0.5 mol% of RuCl3was required. The use of explosive trifluoroperaceticacid, generated in situ, is also avoided.

EMISSIONS CONTROLRe-evaluation and Modeling of a CommercialDiesel Oxidation CatalystY.-D. KIM and W.-S. KIM, Ind. Eng. Chem. Res., 2009, 48, (14),6579–6590

A modelling approach to predict the performance ofa DOC used published experimental data and a newset of conversion experiments. Steady-state experi-ments with DOCs (Pt supported on an Al2O3

washcoat) mounted on a light-duty turbochargeddiesel engine were carried out. The reaction rates forCO, HC, and NO oxidations in diesel exhaust overfresh Pt/Al2O3 were determined in conjunction with atransient 1D heterogeneous plug-flow reactor model.

NOx Abatement for Lean-Burn Engines underLean–Rich Atmosphere over Mixed NSR-SCRCatalysts: Influences of the Addition of a SCRCatalyst and of the Operational ConditionsE. C. CORBOS, M. HANEDA, X. COURTOIS, P. MARECOT, D.DUPREZ and H. HAMADA, Appl. Catal. A: Gen., 2009, 365,(2), 187–193

The NOx removal efficiency of a Pt-Rh/Ba/Al2O3

NSR model catalyst under a lean/rich atmospherewas improved by the addition of a SCR catalyst(Co/Al2O3 or Cu/ZSM-5). Both SCR catalysts wereable to reduce NOx using the NH3 formed during therich cycles on Pt-Rh/Ba/Al2O3. With Cu/ZSM-5,this was independent of the reductant used (CO orH2) and of the reduction time (10, 5 or 2.5 s).

FUEL CELLSOrigin and Quantitative Analysis of the ConstantPhase Element of a Platinum SOFC Cathode Usingthe State-Space ModelS. RICCIARDI, J. C. RUIZ-MORALES and P. NUÑEZ, Solid StateIonics, 2009, 180, (17–19), 1083–1090

A SOFC cathode was investigated using SEM, elec-trochemical impedance spectroscopy and simulationsusing the state-space model. The kinetic parameterswere determined. The triple phase boundary length wasmeasured and its width deduced. A quantitative analysisof the constant phase element using surface roughnessand energy activation distribution is presented.

Fabrication of High Precision PEMFC MembraneElectrode Assemblies by Sieve Printing MethodA. B. ANDRADE, M. L. MORA BEJARANO, E. F. CUNHA, E.ROBALINHO and M. LINARDI, J. Fuel Cell Sci. Technol., 2009,6, (2), 021305 (3 pages)

A sieve printing technique was used for the prepa-ration of PEMFC gas diffusion electrodes. MEAevaluation was carried out in a 25 cm2 single PEMFCwith loadings of 0.4 mg Pt cm–2 and 0.6 mg Pt cm–2

on the anode and cathode, respectively. The MEAshad higher power density than spray printed ones.

Platinum Metals Rev., 2009, 53, (4), 226–227 226

ABSTRACTS

DOI: 10.1595/147106709X475324


Synthesis of Intermetallic PtZn Nanoparticles byReaction of Pt Nanoparticles with Zn Vapor andTheir Application as Fuel Cell CatalystsA. MIURA, H. WANG, B. M. LEONARD, H. D. ABRUÑA and F. J.DiSALVO, Chem. Mater., 2009, 21, (13), 2661–2667

Intermetallic PtZn nanoparticles (1) were synthe-sised by reaction of C-supported Pt nanoparticleswith Zn vapour at 500ºC for 8 h under flowing N2 atatmospheric pressure. The catalytic activities of sup-ported (1) toward formic acid and MeOHelectrooxidation were studied by differential electro-chemical mass spectrometry. (1) exhibited highercurrents for both oxidations than supported Ptnanoparticles with similar particle sizes.

METALLURGY AND MATERIALSFacile Approach to the Synthesis of 3D PlatinumNanoflowers and Their ElectrochemicalCharacteristicsJ. N. TIWARI, F.-M. PAN and K.-L. LIN, New J. Chem., 2009, 33,(7), 1482–1485

3D Pt nanoflowers (1) were synthesised by a poten-tiostatic pulse plating method on a Si substrate.Electrochemical analysis established that (1) had amuch larger active surface area than a Pt thin film bya factor of > 110, and were likely preferentially ori-ented in the (100) and (110) surface planes. (1)exhibited excellent electrocatalytic activity towardMeOH oxidation and a high CO tolerance as com-pared with a Pt thin film.

Fe Oxidation versus Pt Segregation in FePtNanoparticles and Thin FilmsL. HAN, U. WIEDWALD, B. KUERBANJIANG and P. ZIEMANN,Nanotechnology, 2009, 20, (28), 285706 (7 pages)

The oxidation behaviour of differently sized FePtnanoparticles (1) was investigated by XPS and com-pared to a FePt reference film. For the as-preparedsamples Fe3+ is formed, becoming detectable forexposures to pure O2 above 106 langmuir, while Pt0

remains. After annealing at 650ºC, large (1) as well asthe reference film exhibited a 100–1000 timesenhanced resistance against oxidation, whereas small(1) (diameter 5 nm) showed no such enhancement.

Atomic-Level Pd–Au Alloying and ControllableHydrogen-Absorption Properties in Size-Controlled Nanoparticles Synthesized byHydrogen ReductionH. KOBAYASHI, M. YAMAUCHI, R. IKEDA and H. KITAGAWA,Chem. Commun., 2009, (32), 4806–4808

PVP-protected Pd nanoparticles were prepared fromthe alcoholic reduction of PdCl2 in the presence ofPVP. An aqueous solution of HAuCl4 was added andthe mixture was stirred under H2 gas to form Pd-Aualloy nanoparticles. 20 at.% of Au in Pd suppressed H2

absorption completely. The amount of H2 absorptionis controllable by low-concentration alloying with Au.

APPARATUS AND TECHNIQUENanocomposite Based on Depositing PlatinumNanostructure onto Carbon Nanotubes through aOne-Pot, Facile Synthesis Method forAmperometric SensingD. WEN, X. ZOU, Y. LIU, L. SHANG and S. DONG, Talanta, 2009,79, (5), 1233–1237

Pt nanoparticles deposited onto carbon MWNTs,through direct chemical reduction, can electrocatalysethe oxidation of H2O2 and substantially raise theresponse current. Glucose oxidase (GOD) was immo-bilised on the nanocomposite-based electrode with athin layer of Nafion. This glucose biosensor with aGOD loading concentration of 10 mg ml–1 had adetection limit of 3 μM and a response time of 3 s.

BIOMEDICAL AND DENTALInhibition of Transcription by Platinum AntitumorCompoundsR. C. TODD and S. J. LIPPARD, Metallomics, 2009, 1, (4), 280–291

Structural investigations of Pt–DNA adducts andthe effects of these lesions on global DNA geometryare reviewed. Research detailing inhibition of cellulartranscription by Pt–DNA adducts is presented. Amechanistic analysis of how DNA structural distor-tions induced by Pt damage may inhibit RNAsynthesis in vivo was carried out. (155 Refs.)

CHEMISTRYSynthesis and Structural Characterization ofBinuclear Palladium(II) Complexes ofSalicylaldimine DithiosemicarbazonesT. STRINGER, P. CHELLAN, B. THERRIEN, N. SHUNMOOGAM-GOUNDEN, D. T. HENDRICKS and G. S. SMITH, Polyhedron, 2009,28, (14), 2839–2846

The title complexes were synthesised by the reactionof ethylene- and phenylene-bridged dithiosemicar-bazones with Pd(PPh3)2Cl2. Two representative Pdcomplexes were characterised by XRD. The two Pdcentres are coordinated in a slightly distorted square-planar geometry, which gives rise in each case to five-and six-membered chelate rings. The ligands coordi-nate to Pd in a tridentate manner, through thephenolic O, imine N and thiolate S atoms.

Synthesis, Properties and Crystal Structures ofVolatile ββ-Ketoiminate Pd Complexes, Precursorsfor Palladium Chemical Vapor DepositionG. I. ZHARKOVA, P. A. STABNIKOV, I. A. BAIDINA, A. I.SMOLENTSEV and S. V. TKACHEV, Polyhedron, 2009, 28, (12),2307–2312

β-Aminovinylketone ligands CH3C(NH2)CHC(O)CH3

and CH3C(NHCH3)CHC(O)CH3 were synthesised.Their reaction with PdCl2 in an amine mediumafforded the complexes Pd[CH3C(NH)CHC(O)CH3]2

(1) and Pd[CH3C(NCH3)CHC(O)CH3]2 (2). In (1) and(2), the Pd atom exhibits square coordination, Pd O2N2.

CATALYSIS – APPLIED ANDPHYSICAL ASPECTSPreparation of Platinum on Activated CarbonUNIV. KEBANGSAAN MALAYSIA World Appl. 2009/057,992

A catalyst with ≥ 40 wt.% loading of Pt and meanparticle size of 28 μm is prepared by adding a solutionof H2PtCl6 or (NH4)2PtCl4 in aqua regia to activated C powder with particles 20–30 μm in size, pretreatedwith HNO3. A base such as NH4OH is added to raisethe pH to 9.7–9.9. The solution is boiled and calcinedby heating at 120–130°C then at 340–360°C.

Palladium-Gallium Hydrogenation CatalystsMAX-PLANCK-GESELLSCHAFT World Appl. 2009/062,848

Optionally supported, ordered intermetallic PdGacompounds are prepared by reacting a Pd compound,preferably Pd(acac)2, with a Ga compound, preferablya Ga halide, in the presence of a reductant such asLiBEt3H and optionally a solvent such as THF ordiglyme. Alternatively, Pd is reacted with a vaporisedGa compound, such as GaI3. Particular applicationfor the selective conversion of ethyne to ethene in thepresence of an excess of ethene is claimed.

CATALYSIS – INDUSTRIAL PROCESSTwo-Stage Distillate to Gasoline ConversionCONOCOPHILLIPS CO U.S. Appl. 2009/0,134,061

Distillate with research octane number (RON)25–50, is converted to gasoline with RON > 65, bycontact with: (a) 0.5–5 (preferably 0.5–3) wt.% Ptand/or Pd on an acidic support, preferably zeolite, inthe presence of H2, at 220–260ºC, then (b) 0.5–5(preferably 0.5–3) wt.% Ir and optionally Ni on asupport such as SiO2 or Al2O3, at 280–330ºC.

CATALYSIS – REACTIONSIridium Catalyst for Nitrile HydrationUNIV. OKAYAMA Japanese Appl. 2009-023,925

Amides are produced from nitriles under mild con-ditions using a catalyst system formed from an Ircomplex, XIrL2, YIrZ2 or (YIrZ)2, with an electron-withdrawing organic phosphine; where X = a Group15 element or a bidentate ligand containing O–; L = aphosphine or a neutral ligand exchangeable with aphosphine; Y = a multidentate ligand containing C– orN–; and Z = a negatively charged monodentate ligand.

EMISSIONS CONTROLEfficient Treatment of Particulate MatterETM INT. LTD World Appl. 2009/090,447

A catalyst cartridge contains mineral fibres with den-sity 300–1000 g m–3, composed of ≥ 80 wt.% SiO2 withPt and/or Ir, arranged in radial undulations with recti-linear sections of length l perpendicular to the directionof gas flow. The fibres are 0.3–1 mm thick, with dis-tance d between undulations such that l/d = 5–12.

Lean NOx Trap and Reduction CatalystTOYOTA MOTOR CORP Japanese Appl. 2009-028,575

A NOx occlusion and reduction catalyst has Rh sup-ported on two different oxide materials, such as amixture of Al2O3 and ZrO2-TiO2, in the ratio 1:9–5:1.Rh solubility is ≥ 70% in the first and < 70% in thesecond oxide, when heat treated at > 750ºC and at aloading of 0.01–5 wt.% Rh. During lean operation, Rhgoes into solid solution in the first oxide, preventinggrain growth and sintering. In the rich phase, Rh pre-cipitates out of solution to catalyse NOx reduction.

FUEL CELLSMembrane Electrode Assembly EvaluationGM GLOBAL TECHNOL. OPER. INC

U.S. Appl. 2009/0,124,020A PEMFC MEA is soaked in an unsaturated organ-

ic compound, such as 0.5–2.0 wt.% polyoxyethylene(10) oleyl ether (Brij® 97) in H2O, and then stainedwith a strongly oxidising agent, specifically OsO4. TheMEA is embedded in an epoxy and thin sections forviewing using TEM are prepared. Ionomer and cata-lyst particles will appear as dark regions and pores aslight regions, allowing porosity and size and distribu-tion of particles to be determined.

Membrane Electrode Assembly with Anion ExchangeTOSHIBA CORP Japanese Appl. 2009-026,690

A membrane/electrode composite includes ananion exchange substance, deposited on the anodecatalyst layer or the electrolyte membrane, which cap-tures mobile Ru-containing anions to prevent catalystdegradation. The substance is deposited as a film, oras particles with diameter 0.01–50 μm, in mass ratioof 5:95–90:10 relative to the anode catalyst, or at aloading of 1–50 mg cm–2 of electrode surface area.

METALLURGY AND MATERIALSPlatinum Jewellery AlloyHEIMERLE & MEULE GmbH World Appl. 2009/059,736

A Pt alloy consists of (in wt.%): 94.0–96.5 Pt(preferably 95.1–95.5); 2.5–4.5 W (preferably3.7–3.8); 0.5–3.0 Cu (preferably 0.9–1.1); and0.02–2.0 (preferably 0.04–0.07) of at least one of Ru,Rh and Ir, and is free of Au. It offers high hardnessand resistance to abrasion combined with good workability and cold formability. Semi-finished jewellery components are also claimed.

Corrosion-Resistant Platinum-Rhodium AlloyISHIFUKU MET. IND. CO, LTD Japanese Appl. 2009-035,750

A PtRh alloy for high-temperature and electricalapplications is described as possessing good resistanceto corrosion caused by P, Pb, As, B, Bi, Si, Zn, but inparticular P. It consists of 10–40 wt.% Rh with at leastone of (in wt.%): 0.1–5.0 V, Cr, Nb, Mo, Ta, Reand/or W; 0.1–3.0 Mn and/or Co; 0.3–5.0 Ru, Pd, Ir,Au and/or Ag; and/or 0.01–1.0 Al, and the balance Pt.

228

DOI: 10.1595/147106709X474622


NEW PATENTS

Platinum Metals Rev., 2009, 53, (4)

APPARATUS AND TECHNIQUESpark Plug with Iridium Alloy TipHONEYWELL INT. INC U.S. Appl. 2009/0,127,996

A spark plug with electrode tip formed from an Iralloy is presented. The alloy composition is (in wt.%):60–70 Ir, 30–35 Rh, 0–10 Ni and has minor additions(in ppm) either: (a) 3500-4500 Ta and 100-200 Zr, or (b) 50–100 Ce. These allow for better bonding of thetip with the Ni alloy of the electrode body throughinterdiffusion. The Ir alloy offers high wear resistance.

Unsupported Palladium MembranesJ. D. WAY et al. U.S. Appl. 2009/0,176,012

Defect-free, 7.2 μm-thin Pd membranes are formedby electroless plating on a support such as mirror-finished stainless steel, in an EDTA-free plating bathat 50ºC with addition of 1 part per 100 of hydrazinesolution (3 M). The support may be seeded withmetallic Pd crystallites from Pd acetate. A secondmetal such as Cu, Ag or Au may also be deposited byelectroless plating and the membrane homogenisedby annealing. The membrane is freed from the support by scoring the edges. H2 permeabilities maybe equivalent to thicker membranes and H2/N2 selec-tivity can reach 40,000.

Porous Platinum NanoparticlesUNIV. MIYAZAKI Japanese Appl. 2009-062,571

Monocrystalline Pt nanoparticles with nanopores, foruse in catalysts, electrodes or sensors, and their methodof production are described. The particles are sheets2–25 nm thick with outer diameter 30–600 nm. Thepores may have diameter 1–3.5 nm or may be ellipticalor rectangular with dimensions 1 × 3.5 to 3.5 × 10 nm,and are arrayed at regular intervals of 4–5 nm or atintervals varying from 1–5 nm. The particles may becomposed of Pt, Pt and a base metal, or an alloy of Ptwith Pd, Rh, Ir, Ru, Au, and/or Ag.

BIOMEDICAL AND DENTALAnticancer Rh(III) and Ir(III) ComplexesFREIE UNIV. BERLIN European Appl. 2,072,521

Novel octahedral metal(III) polypyridyl complexesM(hal)3(sol)(pp) for the prevention and treatment ofcancer and its metastases are claimed, described asexhibiting superior cytotoxic activity in cell cultures.M is Rh or Ir, preferably Rh. Sol is a solvent, prefer-ably DMSO or H2O; hal is a halogen, preferably Cl orBr, or a psuedohalogenide, preferably SCN; and pp isa polypyridyl ligand, preferably dpq, dppz or dppn.

Ultra-Low Magnetic Susceptibility Palladium AlloysDERINGER-NEY INC U.S. Appl. 2009/0,191,087

Pd alloys for biomedical components compatiblewith the use of magnetic resonance imaging areclaimed. The composition is (at.%): ≥ 75 Pd; 3–20 Sn,Al or Ta; plus one or more of whichever of Sn, Al orTa are not used in the binary composition, and/orNb, W, Mo, Zr or Ti, up to a total of 22 at.%. Thealloys are formulated such that the volume magneticsusceptibility (cgs) is between 3 × 10–6 and –3 × 10–6.

ELECTRICAL AND ELECTRONICSRuthenium-Doped Semi-Insulator for Laser DiodeT. KITATANI et al. U.S. Appl. 2009/0,129,421

A semi-insulating layer is formed by doping a semi-conductor material such as InP with Ru, Os, Rh or Ti,but in particular Ru. It is included between the p-typeand n-type semiconductor layers to limit current leak-age in the window region of a semiconductor laser,particularly a short cavity edge-emitting laser.

Palladium Complex for Printed CircuitsHEWLETT-PACKARD DEV. CO, LP

U.S. Appl. 2009/0,201,333A Pd aliphatic amine complex (1) in a liquid carrier

is inkjet printed on a substrate, a second compositioncontaining a reducing agent such as formic acid isapplied and the substrate is heated at 50–80ºC toreduce (1) to Pd metal. Alternatively, (1) can beapplied as a seed layer for a subsequent conductivemetal such as Pt, Pd, Rh, Au, Cu, Ni or various alloys.

PHOTOCONVERSIONLuminescent Platinum ComplexesARIZONA STATE UNIV. World Appl. 2009/086,209

Pt(II) di(2-pyrazolyl)benzene chloride and itsanalogs, which are obtained by forming an aromaticsix-membered ring, 1,3-di-substituted by aromaticfive-membered heterocyles such as pyrazolyl, imida-zolyl, thiazolyl or substituted groups thereof, andreacting with an acidic Pt-containing solution. Thebenzene may be fluorinated, difluorinated, methylated,or replaced by pyridine. Cl may be replaced by a phe-noxy group. The Pt(II) complexes, which in someembodiments are phosphorescent, are claimed for useas blue or white light emitters in OLEDs.

REFINING AND RECOVERYRuthenium Recovery from Solid ComponentsTOSHIBA KK World Appl. 2009/093,730

Ru is selectively recovered from hard disks, elec-trodes etc. by contact with an aqueous solution to forma Ru compound which is subsequently eluted and sep-arated by filtration. The aqueous solution can be: (a)formic acid, (b) oxalic acid, (c) an acid and sugars, or(d) an acid and formic acid, alcohols, aldehydes or anacetal/hemiacetal compound (or precursors thereof).For (c) and (d), the acid is preferably 1–90 wt.% of thesolution. The solid may also be oxidised by one of O2,air, O3 or H2O2 for second-pass removal of Ru.

Dry Method for Recovering PGMsDOWA METALS AND MINING CO LTD

Japanese Appl. 2009-024,263A sealed electric furnace is charged with spent pgm-

containing solid components and granular Cu oxidehaving a particle diameter of 0.1–10 mm, a powderedreducing agent and a flux, and melting is done at pres-sures < 1 atm. The pgms preferentially dissolve in themolten Cu, and the oxides are removed in the slag,which has final Cu content of < 3%.

229


NAME INDEX TO VOLUME 53Page Page Page Page

Abdelkader, A. 224

Abe, T. 52, 106

Abruna, H. D. 227

Abu Sheikha, G. 176

Actis Grande, M. 200

Adams, R. D. 50

Adler, J. 175

Adschiri, T. 154

Advani, S. G. 175

Ager, D. J. 203, 204

Agert, C. 154

Aggarwal, V. K. 88

Akçin, N. 105

Albrecht, B. 40

Al-Noaimi, M. 176

Alonso, E. 43

Alvarez, P. J. J. 105

Amore, S. 51

An, G. 105

Ananikov, V. P. 105

Anderson, C. 41

Anderson, J. A. 112, 222

Andrade, A. B. 226

Andrews, P. 36

Antipin, M. Yu. 105

Antolini, E. 51

Antonova, O. V. 138

Anzai, Y. 51

Arbizo, C. 43

Arico, A. S. 151

Aronson, J. 36

Arunachalampillai,

A. 52

Auberson, A. 25

Baca, E. 40

Bäckvall, J.-E. 203

Baddeley, C. 222

Bagshawe, K. 36

Baidina, I. A. 227

Balle, P. 175

Balzani, V. 45, 46

Barigelletti, F. 45

Barnard, C. 36, 67

Basi, M. 41

Battaini, P. 21, 198, 199

Beebe, Jr., T. P. 175

Beletskaya, I. P. 105

Bertel, E. 176

Bhat, V. V. 176

Bhushan, B. 52

Blankenstein, U. 41

Blaser, H.-U. 207

Blatter, A. 189

Blom, D. A. 50

Bloxham, L. 179

Blumberg, P. 43

Boggs, M. E. 175

Bonder, M. J. 51

Book, D. 84

Booyens, S. 224

Borisov, S. M. 106

Boro, B. J. 52

Borzone, G. 51

Bousa, M. 41

Bouzek, K. 148

Boyd, J. E. 226

Braibant, C. 40

Breit, B. 207

Brelle, J. 189

Brock, P. 36

Bull, S. 89

Bullock, J. 40

Bullock, J. P. 106

Bultel, Y. 154

Burch, R. 223

Byriel, I. P. 148

Calman, K. 36

Calvert, H. 36

Cameron, D. S. 147

Campagna, S. 45

Campbell, C. 221

Capela, S. 170

Captain, B. 50

Carlson, B. 106

Casey, P. 42

Catlow, R. 221

Chakraborty, D. 149

Chang, L. 105

Chaplin, D. 206

Chayama, K. 102

Chellan, P. 227

Chen, C.-Y. 52

Chen, J.-G. 52

Chen, W. 86

Cho, B.-G. 106

Choi, J.-S. 169

Chong, L. C. 50

Chown, L. H. 2, 155

Christgen, B. 152

Christie, D. A. 35

Claassen, P. 82

Clarke, N. 41

Colacot, T. J. 183

Compagnoni, G. 188

Contescu, C. I. 176

Cooke, S. 43

Corbos, E. C. 226

Cordin, M. 176

Cornish, L. A. 2, 69, 155

Correia, I. 176

Cortes Felix, N. 164

Corti, C. W.

21, 24, 198, 200

Coughlin, M. 42

Counsell, J. 223

Courtois, X. 226

Creeth, A. M. 151

Cunha, E. F. 226

Curry, R. J. 50

Danks, M. 198

Davies, P. 86, 87

Davis, S. 25

Dawson, G. 200

De Castro, E. 40

de Vries, A. 204

Deisl, C. 176

Delsante, S. 51

Demkowicz, P. 105

Derrick, A. 226

Deutschmann, O. 175

Dinderman, M. A. 106

Ding, K. 105

Dingwall, L. 224

DiSalvo, F. J. 227

Diskin-Posner, Y. 52

Divakar, D. 50

Do, J. S. 175

Doná, E. 176

Dong, S. 227

Douglas, A. 2, 69

Douglas, P. 51

Dressick, W. J. 106

Dudek, D. 51

Duesler, E. N. 52

Dufour, J. 176

Duisberg, M. 175

Dujardin, C. 168

Dupont, J. 67

Duprez, D. 226

Dyson, P. J. 35

Eccarius, S. 154

Edwards, D. 223

Edwards, H. 89

Edwards, J. 223

Egebo, T. 147

Eichinger, B. E. 106

El-Eswed, B. 176

Enders, M. 50

Epling, W. 168

Fang, Y.-L. 105

Feller, M. 52

Ferguson, S. 40

Fermvik, A. 101

Ficicilar, B. 153

Fischer-Bühner, J.

22, 201

Fisher, J. M. 153

Foo, R. 164

Fordred, P. 89

Forzatti, P. 50

Fossey, J. S. 86, 89

Franchini, C. 176

Frost, C. 86, 89

Frost, J. 85, 223

Fryé, T. 22, 23

Furimsky, E. 135

Furukawa, Y. 88

Gallego, N. C. 176

Gamino-Arroyo, Z. 100

Gammon, R. 82

Gan, J. 105

Gayduk, K. A. 105

Gellman, A. 222

George, E. 145

Georges, S. 154

Gilby, S. 152

Giunti, T. 82

Gladden, L. 222

Glaner, L. 2, 155

Gökaliler, F. 150

Goldberg, K. I. 52

Golunski, S. E. 221, 223

Gonzalez, E. R. 51

Gopinath, C. S. 224

Grahame-Smith, D.

36

Gralla, R. 36

Grant, R. A. 100

Gray, P. 150

Green, R. 79

Gregory, D. 83

Greinke, R. 202


Griffith, W. P. 209

Grigg, R. 226

Grimwade, M. 202

Grundmann, A. 154

Gülzow, E. 151

Guo, M. 50

Haas, W. 106

Hadjipanayis, G. C. 51

Hagelueken, C. 41

Hallikainen, A. 105

Hamada, H. 226

Hammond, C. 224

Han, B. 105

Han, L. 227

Hancock, F. 188, 204

Haneda, M. 226

Harrap, K. 36

Harris, R. 84

Harrison, J. 79

Haruta, M. 222

Heck, K. N. 105

Helliwell, J. 81

Hendricks, D. T. 227

Hepworth, R. 79

Hernández, J. R. 166

Hill, P. J. 69

Hiro, T. 165

Hiromi, C. 52

Ho, K.-C. 52

Hoeschele, J. 36

Hoge, G. 207

Holdcroft, S. 52

Howard, K. 223

Huang, C.-J. 105

Huang, Y. H. 51

Huot, J. 176

Hutchings, G. 222

Huuhtanen, M. 105

Ianniello, R. 42

Ikariya, T. 203, 208

Ikeda, N. 106

Ikeda, R. 227

Inoue, M. 52

Irandoust, M. 106

Iron, M. A. 52

Itakura, T. 106

Iwata, Y. 165

Iyngaran, P. 224

Izatt, S. 41, 43

Jackson, D. 223

Jacobsen, R. 41, 43

James, K. 43

Jenkins, S. 221

Jin, Y. 176

Jiskra, J. 42

Johnson, M. T. 52

Johnson, T. V. 37

Jollie, D. 182

Jones, H. 202

Jones, M. 202

Joshaghani, M. 106

Judson, I. 36

Jun, B.-H. 50

Kallinen, K. 105

Kallio, T. 58

Kaminsky, W. 106

Kanai, M. 226

Kanehara, M. 106

Kang, H. 50

Keep, A. 226

Keiski, R. L. 105

Kemp, R. A. 52

Kendall, K. 78, 80

Khrustalev, V. N. 105

Khurshid, H. 51

Kiely, C. 222

Kim, I.-K. 106

Kim, J.-H. 50

Kim, P. S. 165

Kim, W.-S. 226

Kim, Y.-D. 226

Kitagawa, H. 227

Kitami, T. 52

Kittelson, D. B. 31

Kjellin, P. 51

Klein, J.-M. 154

Klerke, A. 149

Klimant, I. 106

Klotz, U. 201

Kobayashi, H. 227

Koch, F. 79

Kohl, G. 50

Kolb, G. 172

Kolli, T. 105

Kondo, Y. 226

Kontturi, K. 58

Kossov, A. 98

Kramer, E. P. 101

Krog, O. 147

Kuai, P. 50

Kuerbanjiang, B. 227

Kumar, P. 128

Kureti, S. 175

Kuriyama, W. 205

Kurz, T. 154

Kwak, K. J. 52

Lapidus, G. T. 100

Latini, A. 176

Le Ret, C. 205

Lee, M. H. 175

Lee, S.-H. 50

Lee, W.-Y. 153

Lee, Y.-S. 50

Lei, Y. J. 43

Leitus, G. 52

Lennon, I. 205

Leonard, B. M. 227

Lewis, J. 85

Li, G. 176

Li, J. 175

Li, J.-Y. 52

Liang, X. 50

Liang, Z. X. 105

Libuda, J. 170

Lietti, L. 50

Lin, K.-L. 227

Lin, Z. 176

Linardi, M. 226

Linderoth, S. 154

Lindner, E. 176

Lippard, S. J. 227

Liu, C.-J. 50

Liu, Y. 227

Liu, Z. 105

Loetscher, L. H. 226

Lohwongwatana, B. 25

Lopes, T. 51

Loschialpo, P. 106

Lu, W. 176

Luo, Y. 176

Lupton, D. 42, 145

Ma, D. 176

Maerz, J. 24, 200

Maggian, D. 202

Mahittikul, A. 105

Manikandan, D. 50

Mansur, M. B. 100

Manziek, L. 40

Marecot, P. 226

Martin, A. 79

Matsubara, H. 169

Matsuzono, Y. 175

Mauser, A. 78

McCarney, J. 172

McCloskey, J. 25

McFarlane, A. 224

Mekasuwandumrong,

O. 175

Melke, J. 153

Miao, S. 105

Miller, J. T. 105

Millet, C.-N. 170

Milstein, D. 52

Miner, W. 36

Mishra, R. 202

Miura, A. 227

Modolo, G. 101

Montero, J. 224

Mora Bejarano, M. L.

226

Morgan, K. 223

Mori, K. 226

Muhamad, E. N. 51

Murakumo, T. 69

Murata, K. 205

Murrer, B. 36

Nagarajan, S. 223

Nakatsuji, T. 166, 175

Nakken, T. 83

Narita, H. 101

Naylor, R. 36

Nishimura, T. 89

Nova, I. 50

Nunez, P. 226

Nuss, G. 106

Nutt, M. O. 105

Ó Dubhghaill, C. 202

Obuchi, A. 167

Offer, G. J. 219

Ohara, S. 153, 154

Ouyang, F. 50

Palacio, M. 52

Palmer, S. 78

Palmqvist, A. E. C. 51

Pan, F.-M. 105, 227

Pan, Z. F. 43

Pandey, D. K. 91

Panfilov, P. 138

Panpranot, J. 175

Park, H.-S. 106

Park, J. 50

Park, J.-G. 106

Park, J.-Y. 106

Parkinson, P. 41

Parodi, N. 51

Penfold, G. 25

Pentz, L. 98

Pereira Morais, M. P.

89

Petti, D. 105

Pfaltz, A. 205

Pfeffer, M. 67

Page Page Page Page


Phelan, G. D. 106

Phillips, P. R. 27

Pickup, P. G. 175

Pilyugin, V. P. 138

Ploof, C. 201

Pollet, B. G. 78

Poulston, S. 112

Pourshahbaz, M. 106

Prasad, A. K. 175

Prasassarakich, P. 105

Praserthdam, P. 175

Pratsinis, S. E. 11

Price, G. 86

Pridmore, S. 89

Prior, J. 41

Pritzkow, H. 50

Puhakka, E. 153

Quisenberry, L. R. 226

Rafiee, E. 106

Raja, R. 50

Rangel, C. M. 150

Rau, J. V. 176

Raykhtsaum, G. 202

Rayment, T. 222

Redinger, J. 176

Rempel, G. L. 105

Reynolds, B. 36

Ricciardi, S. 226

Ricketts, S. R. 51

Riess, M. 40

Robalinho, E. 226

Roberts, W. 225

Robinson, D. J. 100

Rossmeisl, J. 152

Rowsell, L. 112

Rudd, J. 36

Ruiz-Morales, J. C. 226

Ryan, M. 216

Saf, R. 106

Sage, P. 25

Samulski, E. T. 51

Sánchez-Loredo, M. G.

102

Sanderson, R. 43

Sanger, G. 36

Santasalo, A. 58

Saruyama, M. 106

Sato, K. 154

Sato, N. 175

Satsuma, A. 164, 165

Sawabe, K. 165

Scandola, F. 45

Schädel, B. T. 175

Schmehl, R. 46

Schmuck, M. 106

Schott, F. J. P. 175

Schulz, G. L. 52

Schuster, H. 25, 201

Shang, L. 227

Shaw, M. 88, 89

Sheu, J.-T. 105

Shibasaki, M. 86, 226

Shimizu, K. 165

Shimon, L. J. W. 52

Shinozaki, K. 106

Shulgin, D. 42

Shunmoogam-Gounden,

N. 227

Si, Y. 51

Silva, F. 202

Silva, S. R. P. 50

Singh, D. 91

Singhal, S. C. 147

Sivakumar, T. 50

Sjunnesson, L. 148

Skea, J. 78

Smith, A. W. J. 112

Smith, D. 106

Smith, G. S. 227

Smith, R. A. P. 55, 109

Smolentsev, A. I. 227

Sodeoka, M. 208

Somboonthanakij, S.

175

Somorjai, G. 221

Sorel, C. 101

Sridharan, V. 226

Stabnikov, P. A. 227

Stadelmann, P. A. 70

Stolojan, V. 50

Stone, F. 221

Strauss, J. 25, 201

Stringer, T. 227

Strobel, R. 11

Sullivan, S. P. 175

Sun, S.-G. 106

Sun, Y. 207

Sunjuk, M. 176

Süss, R. 2, 69, 155

Suzuki, K. 203

Sweidan, K. 176

Taguchi, A. 52

Takahashi, N. 170

Takeguchi, T. 51

Takemoto, Y. 203

Takeshita, K. 102

Takeuchi, T. 226

Tanaka, K. 206

Tandon, P. 123

Tang, J. 52

Tanizawa, M. 52

Tansey, E. M. 35

Tansey, T. 36

Tao, R. 105

Tasker, P. A. 102

Tattersall, D. 36

Taylor, H. S. 221

Teague, T. 201

Teranishi, T. 106

Terry, L. A. 112

Therrien, B. 227

Thomas, J. M. 50

Thomson, A. 36

Thumberg, M. A. 101

Tian, N. 106

Tian, X. 154

Tierney, B. 40

Tiwari, J. N. 227

Tkachev, S. V. 227

Todd, R. C. 227

Toops, T. J. 170

Trufan, E. 50

Tully, J. 43

Twigg, M. V. 27, 135

Tyler, C. 41

Tzeng, T.-C. 105

Ueda, W. 51

Umetsu, M. 154

Uozumi, Y. 175

Uttam, K. N. 123

Vargas, C. 101

Verdooren, A. 202

Wagner, G. 50

Walker, J. 98

Walport, M. 36

Wang, G. 51

Wang, H. 227

Wang, L. 176

Wang, Q. 176

Ward, M. D. 45

Welton, T. 176

Wen, D. 227

Wendt, O. F 52

Wenn, J. 36

Whitby, M. 214

Whitney, S. 226

Wiedwald, U. 227

Wiesner, K. 25, 201

Wilkinson, L. 36

Williams, G. 46

Williams, J. M. J. 86

Williams, R. 36

Williamson, I. 81

Willis, M. 86

Wills, M. 83, 84

Wilson, K. 225

Wiltshaw, E. 36

Wisniewski, M. 102

Wong, M. S. 105

Wong, W.-Y. 176

Woods, T. 36

Woollam, S. F. 100

Wright, J. C. 200, 202

Wright, K. 105

Wu, C.-G. 52

Wu, S.-J. 52

Xie, Y. 105

Xu, J. B. 105

Yadawa, P. K. 91

Yamada, Y. M. A. 175

Yamaguchi, T. 175

Yamamoto, H. 204

Yamashita, H. 226

Yamatsugu, K. 226

Yamauchi, M. 227

Yermakov, A. 138

Yezerets, A. 169

Yonkeu, A. 176

York, A. P. E. 221

Yoshioka, N. 226

Yu, X. 175

Zabetakis, D. 106

Zhang, F.-Y. 175

Zhang, J. 219

Zhao, T. S. 105

Zharkova, G. I. 227

Zhou, G.-J. 176

Zhou, Z.-Y. 106

Zhu, L. D. 105

Zhu, R. 50

Ziegenhagen, R. 189

Zielonka, A. 25

Ziemann, P. 227

Zito, D. 25

Zou, X. 227

Zucca, R. 176

Zuo, Y. 52

Züttel, A. 84

Page Page Page Page


SUBJECT INDEX TO VOLUME 53Page Page

a = abstract

(Z)-Acetamidocinnamic Acid Methyl Ester, reduction 203

Acetoxylation 221

Adsorption, ethylene, Pd-promoted zeolite 112

AFM Probes, Pt-coated Si, thermally-treated, a 52

Alcohols, aerobic oxidation, in H2O, a 175

aliphatic, in alkylation, a 226

benzyl, substituted, in alkylation, a 226

chiral, by reduction of esters 203

EtOH, oxidation 58, 105

electro-, a 106

fuels, for PEFC 58

generation of H2 78

MeOH, electrooxidation, a 227

oxidation, a 227

solvent, a 176

secondary, dynamic kinetic resolution 203

racemisation 203

Aldehydes, addition, across multiple C–C 86

fuels, for PEFC 58

Alkenes, formation 86

hydroacylation 86

hydrogenation, a 105

unfunctionalised, asymmetric reduction 203

Alkylation, 4-hydroxy coumarin, a 226

4-hydroxy-2-quinolones, a 226

quinolin-4(1H)-one, a 226

Alkylidene Carbenoids, by activation of alkynes 86

Alkynes, activation 86

hydroacylation 86

Amides, α-arylation 183

Amination, Buchwald-Hartwig, palladacycle catalysts 67

Amines, coupling reactions 183

Ammonia, storage 164

synthesis 135

Antimicrobial Agents 11

Apparatus and Technique, a 51, 227

Aryl Halides, coupling reactions 183

αα-Arylation, amides 183

esters 183

Autocatalysts, new production facility, for Russia 98

pgm demand, impact of CO2 legislation 179

recycling 40

Bacteria, catalytic inactivation, a 226

Biomedical and Dental, a 227

Book Reviews, “Carbons and Carbon Supported

Catalysts in Hydroprocessing” 135

“Fuel Processing: for Fuel Cells” 172

“Palladacycles: Synthesis, Characterization and

Applications” 67

“PEM Fuel Cell Electrocatalysts and Catalyst

Layers: Fundamentals and Applications” 219

“Photochemistry and Photophysics of

Coordination Compounds”, Parts I & II 45

“The Discovery, Use and Impact of Platinum Salts

as Chemotherapy Agents for Cancer” 35

Buchwald-Hartwig Amination, palladacycle catalysts 67

Butane, steam reforming, a 175

CAD/CAM, jewellery 21, 198

Cancer, anti-, drugs, cisplatin 35

palladacycles 67

Pt compounds, a 227

Capacitors, DRAM, Ru bottom electrodes, a 106

Carbon, pgm/activated charcoal, catalysts 135

pgm/C, catalysts 135

supported catalysts, hydroprocessing 135

Carbon Oxides, CO, clean-up, in fuel processing 172

contaminated gas, low pressure operation of PEFC 147

emissions, diesel 179

Carbon Oxides, CO, (cont.)+ H2, reduction of NOx, lean conditions, a 175

+ O2 221

oxidation, in diesel exhaust, a 226

selective catalytic reduction 164

selective oxidation 11

tolerant catalysts, for PEM fuel cells 219

CO

2

, emissions, legislation 179

Casting, industrial, Pt 209

investment, Pd alloys 21, 198

Pt alloys 21, 198

Catalysed Soot Filters 27, 179

Catalysis, Applied and Physical Aspects, a 50, 105, 226

asymmetric 203

book reviews 67, 135

concepts 221

conferences 86, 164, 203, 221

methodology 221

Reactions, a 50, 105, 175, 226

theories 221

Catalysts, book reviews 67, 135

C supported, hydroprocessing 135

four-way, see Four-Way Catalysts

heterogeneous, precious metals, for industry 40

surface characterisation, by XPS 55, 109

leaching, for new catalytic reactions, a 105

NOx control 27

petroleum, spent, sampling 40

pgm/activated charcoal, preparation 135

pgm/C, preparation 135

pgms, catalytic aftertreatment, vehicle emissions 221

precious metals, treatment, in plasma heater reactors 40

recycling, a 50, 226

refinery, precious metals, treatment, in PlasmaEnvi® 40

supported pgms, by flame synthesis 11

three-way, see Three-Way Catalysts

Catalysts, Iridium, Ir/γ-Al2O3, soot and NOx removal, a 50

Ir/ZSM-5, soot and NOx removal, a 50

IrBa/WO3-SiO2, CO-SCR 164

Catalysts, Iridium Complexes, [Cp*IrCl2]2, alkylation,

4-hydroxy coumarin, 4-hydroxy-2-quinolones,

quinolin-4(1H)-one, solvent-free heating, a 226

‘hydrogen borrowing’, for formation of C–C, C–N 86

[Ir(COD)(PCy3)(py)]PF6, hydrogenation of NRL, a 105

Ir Me-BoPhozTM, reduction of α,β-enoic acids 203

Ir phosphoramidites, synthesis of phenylalanines 203

Ir(III) quinolyl-functionalised Cp, hydrogenation, a 50

P,N-ligands, asymmetric reduction of alkenes 203

Catalysts, Osmium Complexes, OsO4 immobilised onto

polystyrene-sg-imidazolium resin,

dihydroxylation of olefins, a 50

Catalysts, Palladium, Au-Pd, direct synthesis of H2O2 221

preparation, pretreatment 221

Au-Pd/Al2O3, direct synthesis of H2O2 221

Au-Pd/C, direct synthesis of H2O2 221

Au-Pd/TiO2, direct synthesis of H2O2 221

Co/Pd-HFER, NO2-CH4 reaction 164

combustion, in fuel processing 172

diesel emission control systems 179

diesel oxidation catalysts 174

electrocatalysts, Pd-based, formic acid oxidation 58

Pd/C, anodes, for DFAFC, a 175

Pd/TiO2/C, anodes, for PEFC, a 51

Pd-Pt/hollow core mesoporous shell C, for PEMFC 147

Pt-Pd/C, for DEFCs, a 51

PdRu nanoparticles, anodes, for DMFC 147

nano-Pd/SiO2, 1-heptyne hydrogenation, a 175

by one-step flame spray pyrolysis, a 175

Pd(111), CO + O2 221

Pd, + Au, acetoxylation 221

+ Bi additive, hydrogenation 221

hydrodechlorination, a 105

Catalysts, Palladium, (cont.)Pd-on-Au, hydrodechlorination, a 105

Pd/activated charcoal, hydrogen activation 135

Pd-Al2O3, NO+H2+O2 164

Pd/Al2O3, Ar plasma reduced; glucose selective

oxidation, a 50

C5 olefin hydrogenation 221

effect of S, diesel oxidation, a 105

enantioselective hydrogenation 11

H2 thermally reduced; glucose selective oxidation, a 50

Pd/Ba/Al2O3, NOx storage 164

Pd/bentonite, hydrogenation of citral, a 50

preparation, effect of reduction, a 50

Pd/C, C–C bond forming processes 135

direct carbonylation reactions 135

dissociative H2 chemisorption 135

hydrogenation reactions 135

hydrogenolysis reactions 135

Pd/C black, hydrogen activation 135

Pd/CeO2, effect of S, diesel oxidation, a 105

Pd/graphite, hydrogen activation 135

Pd/La-Al2O3, catalytic combustion 11

Pd-LaCoO3, NO+H2+O2 164

Pd/La2O3, catalytic combustion 11

Pd/sepiolite, Heck reactions, a 105

hydrogenation of alkenes, a 105

preparation, using an ionic liquid, a 105

Pd/SiO2, 1-heptyne hydrogenation, a 175

hydrogenation 11

Pd/TiO2, inactivation of bacteria, a 226

Pd/ZrO2, effect of S, diesel oxidation, a 105

Pd-fullerite, 1-ethynyl-1-cyclohexanol hydrogenation, a 50

Pd-Pt/Al2O3, CH4 combustion 11

Pt/Pd, catalysed soot filter 27

diesel oxidation catalyst 27, 37

Pt/Pd/Au, diesel oxidation catalyst 37

Catalysts, Palladium Complexes, amphiphilic resin-

dispersion of Pd nanoparticles: aerobic oxidation

of alcohols, in H2O; hydrodechlorination of

chloroarenes, a 175

palladacycles, Buchwald-Hartwig amination 67

Heck, Sonogashira, Suzuki couplings 67

[Pd(μ-Br)(tBu3P)]2, alkyl thiols + aryl bromides 183

alkyl thiols + aryl iodides 183

aryl bromides + benzenethiol 183

aryl chlorides + amines 183

α-arylation of amides, esters 183

carbon–carbon bond formation 183

carbon–heteroatom coupling 183

characteristics 183

cyanation 183

handling 183

N-cyclohexylaniline + bromobenzene 183

N-methylaniline + 3-bromothiophene 183

O2 sensitivity 183

Suzuki coupling of sterically bulky aryl bromides 183

α-vinylation of esters, ketones 183

Pd enolate + DM-SEGPHOS, aldol reaction 203

α-fluorination reaction 203

Mannich reaction 203

Michael reaction 203

Pd(OAc)2 + BINAP, N-cyclohexylaniline +

bromobenzene 183

Pd(OAc)2 + tBu3P, N-cyclohexylaniline +

bromobenzene 183

Pd(OAc)2 + Xantphos, N-cyclohexylaniline +

bromobenzene 183

Pd particles/organic S ligands/phosphanes,

synthesis of cyclic vinyl sulfides, a 105

Pd particles/organic Se ligands/phosphanes,

synthesis of cyclic vinyl selenides, a 105

(tBu3P)Pd(0), from [Pd(μ-Br)(

tBu3P)]2 183

Catalysts, Platinum, Ba-K/Pt-Rh/A-ZT, NOx storage

and reduction 164

Ba-K/Pt-Rh/AZT, NOx storage and reduction 164

Catalysts, Platinum, (cont.)CO clean-up, in fuel processing 172

combustion, in fuel processing 172

diesel aftertreatment 179

electrocatalysts, Corich core-Ptrich shell/C, ORR, a 175

Pd-Pt/hollow core mesoporous shell C, for PEMFC 147

Pt, anodes, for PEMFC 147

sieve printed, for PEMFC, a 226

cathodes, for fuel cells 147

for MFC 147

for PEMFC 147

sieve printed, for PEMFC, a 226

for SOFC, a 226

electrodes, for PEMFC 147

spray printed, for PEMFC, a 226

MEAs, for PEMFC 147

for PEMFC 175, 219

Pt/C, anodes, for PEFC, a 51

cathodes, for DMFC 147

electrodes, for DEFC 147

Pt/Vulcan XC-72 C, cathodes, for PEFCs 58

Pt-Au, surface characterisation, by XPS 55, 109

Pt-Bi, formic acid oxidation 58

Pt3Ni, cathodes, for fuel cells 147

Pt-Pd/C, for DEFCs, a 51

PtRu, anodes, for DMFC 147

Pt-Ru, anodes, for PEFC 147

for PEM fuel cells 219

Pt-Ru/C, anodes, for DMFC 147


Pt-Ru/Vulcan XC-72 C, anodes, for PEFCs 58

Pt-Sn, ethanol oxidation 58

Pt-Sn/C, electrodes, for DEFC 147

PtZn nanoparticles, for fuel cells, a 227

FePt-γ-CD, aqueous hydrogenations, a 226

Pd-Pt/Al2O3, CH4 combustion 11

production of H2SO4 40

Pt, catalysed soot filter 27

diesel oxidation catalyst 27

layer, diesel particulate filter 37

Pt/activated charcoal, hydrogen activation 135

Pt/Al2O3, by flame synthesis 11

by precipitation/impregnation 11

combustion of CO 164

enantioselective hydrogenation 11

Pt/γ-Al2O3, removal of soot and NOx, a 50

Pt/Al2O3 washcoat, diesel oxidation catalyst, a 226

Pt/(75% Al-21% BaCO3-2% K2CO3), NOx storage 164

Pt-Ba/Al2O3, lean NOx trap, regeneration with H2, a 50

Pt/Ba/Al2O3 washcoat, lean NOx trap 164

Pt/Ba/ZrO2/Al2O3, four-way catalyst 164

Pt/BaCO3/Al2O3, NOx storage-reduction 11

Pt/C, dissociative H2 chemisorption 135

Pt/C black, hydrogen activation 135

Pt/Ce-Pr-ZrOx, NOx storage 164

Pt/CeO2, NH3 storage 164

Pt/CeO2-Al2O3, NOx storage and reduction 164

Pt sintering 164

Pt/CexZr1–xO2, three-way catalyst 11

Pt/graphite, hydrogen activation 135

Pt/TiO2, inactivation of bacteria, a 226

oxidation 11

photocatalysis 11

Pt/WO3/ZrO2, NOx + H2, in O2-rich exhaust, a 175

Pt-Ni/alumina, oxidative steam reforming 147

Pt/Pd, catalysed soot filter 27

diesel oxidation catalyst 27, 37

Pt/Pd/Au, diesel oxidation catalyst 37

Pt-Rh/Al2O3, partial oxidation of CH4 11

Pt-Rh/Ba/Al2O3, NSR model catalyst, a 226

+ SCR catalyst, a 226

NOx abatement, a 226

PtSn2, selective hydrogenation, a 50

Catalysts, Platinum Complexes, activation of alkynes 86

amphiphilic resin-dispersion of Pt nanoparticles, a 175


Page Page

Catalysts, Rhodium, Ba-K/Pt-Rh/A-ZT, NOx storage

and reduction 164

Ba-K/Pt-Rh/AZT, NOx storage and reduction 164

exhaust gas reforming 221

Pt-Rh/Al2O3, partial oxidation of CH4 11

Pt-Rh/Ba/Al2O3, NSR model catalyst, a 226

+ SCR catalyst, a 226

NOx abatement, a 226

reforming, in fuel processing 172

Rh/Al2O3, selective hydrogenation 11

Rh/C, dissociative H2 chemisorption 135

hydrogenation of oximes 203

Rh/CexZr1–xO2, syngas production 11

Rh/cordierite monolithic honeycomb, reforming, a 175

Rh nanoparticles/zeolite, lean NOx–CO–H2, a 175

RhOx nanoparticles/zeolite, lean NOx–CO–H2, a 175

RhSn2, selective hydrogenation, a 50

Catalysts, Rhodium Complexes, H2 from alcohols 78

Rh BINAP, [2 + 2 + 2] cycloadditions, for preparation

of axial chiral aromatic compounds 203

Rh(CO)2(acac) + DiazaPhos-SPE, hydroformylation 203

Rh(dppe)]ClO4, addition of aldehydes across multiple

C–C, + C–H activation and C–C formation 86

Rh H8-BINAP, [2 + 2 + 2] cycloadditions, for

preparation of axial chiral aromatic compounds 203

Rh MandyPhosTM

, asymmetric hydrogenation 203

Rh Me-BoPhozTM

, reduction of α,β-enoic acids 203

Rh MonoPhosTM


preparation of Aliskiren 203

Rh(nbd)2, P,N-complex; P,P-complex, asymmetric

reduction of (Z)-acetamidocinnamic acid

methyl ester 203

Rh(III) quinolyl-functionalised Cp, hydrogenation, a 50

Rh SEGPHOS®

, [2 + 2 + 2] cycloadditions, for

preparation of axial chiral aromatic compounds 203

Rh TangPhos, reduction of dehydroamino acids 203

reduction of enamides 203

reduction of itaconates 203

Rh–Xyl-PhanePhos, reduction of α,β-enoic acids 203

Catalysts, Ruthenium, electrocatalysts, PdRu

nanoparticles, anodes, for DMFC 147

PtRu, anodes, for DMFC 147

Pt-Ru, anodes, for PEFC 147

for PEM fuel cells 219

Pt-Ru/C, anodes, for DMFC 147


Pt-Ru/Vulcan XC-72 C, anodes, for PEFCs 58

Ru/C, ammonia synthesis 135

RuSn2, selective hydrogenation, a 50

Catalysts, Ruthenium Complexes, asymmetric transfer

hydrogenation of ketones 203

bis(η5-2,4-dimethylpentadienyl)ruthenium(II) +

MandyPhosTM


generation of H2, from alcohols 78

[HNEt3]+[(Ru{η5

-C5H5}{PPh3}2)2(PW12O40)]–

221

‘hydrogen borrowing’, for formation of C–C, C–N 86

monomeric, secondary alcohol racemisation 203

[RuCl2(P-Phos)(DMF)n], reduction of α,β-enoic acids 203

reduction of γ,δ-enoic acids 203

RuCl2[(R)-P-Phos][(S)-DAIPEN], aryl ketone reduction 203

RuCl2[(S)-xyl-P-Phos][(S)-DAIPEN], in synthesis of

imidazol[1,2-a]pyridine BYK-311319 203

RuCl3, dihydroxylation, in synthesis of Tamiflu®

, a 226

Ru–diamine, reduction of esters 203

Ru–DM-SEGPHOS®

, synthesis of sitagliptin 203

Ru MonoPhosTM

, reduction of carbonyl groups 203

Shvo catalyst, secondary alcohol racemisation 203

Ceramic Fusion Technique, PdAlRu alloys 189

Chemistry, a 52, 106, 176, 227

Chemotherapy Agents, for cancer, Pt salts 35

Chlorinated Ethenes, hydrodechlorination, a 105

Chloroarenes, hydrodechlorination, a 175

Chorine, corrosion of Pt, a 176

Cisplatin 35

Citral, vapour-phase selective hydrogenation, a 50

Colloids, Pd-Sn, inkjet printing, a 106

Combustion, catalytic 11

CH4 11

in fuel processing 172

Composites, Pt nanoparticle–graphene, a 51

Conferences, 32nd Annual Conference of Precious

Metals, U.S.A., 2008 40

Fuel Cells Science and Technology 2008, Denmark 147

Hydrogen Fuel Cells: For a Low Carbon Future, U.K.,

2008 78

5th International Conference on Environmental

Catalysis, Northern Ireland, 2008 164

18th International Solvent Extraction Conference,

U.S.A., 2008 100

Metals in Synthesis 2008, U.K. 86

Novel Chiral Chemistries Japan 2009 203

SAE 2008 World Congress, U.S.A. 37

22nd Santa Fe Symposium®, U.S.A., 2008 21

23rd Santa Fe Symposium®, U.S.A., 2009 198

The Taylor Conference 2009, U.K. 221

Corrosion, Pt, Cl2-induced, a 176

Coupling Reactions, C–C 183

C–heteroatom 183

palladacycle catalysts 67

Creep, Pt86:Al10:Z4, Z = Cr, Ir, Ru 2

CVD, precursors, Pd β-ketoiminates, a 227

Cyanation 183

Cycloaddition, [2 + 2 + 2], preparation of axial

chiral aromatic compounds 203

1,5,9-Cyclododecatriene, selective hydrogenation, a 50

Cyclododecene, from 1,5,9-cyclododecatriene, a 50

Defect Structure, polycrystalline Ir 138

Deformation, plastic, polycrystalline Ir 138

Dendrimers, G4.5-COOCH3 PAMAM, + Pd2+

, a 176

Dental, alloys, Pd-Ag-based 21

Pd74.0-In5.0-Cu14.5Ga1.6Sn4.9 21

Deuterium, permeation, Pd81Pt19 membrane, a 51

Diatomic Molecules, PtC, PtH, PtN, PtO, properties 123

Diesel, emissions control 27, 37, 164, 174, 179, 226

engines 179

exhaust gas mixtures, a 105

particulate matter, emissions, control 27

Diesel Oxidation Catalysts 27, 37, 105, 174, 179, 226

Diesel Particulate Filters 27, 37, 179

Dihydroxylation, olefins, a 50

in synthesis of Tamiflu®

, a 226

DMSO, solvent, a 176

Dynamic Kinetic Resolution, secondary alcohols 203

Elastic Constants, higher-order, Os, Ru 91

Electrical and Electronics, a 52, 106

Electrochemistry, a 106

preparation, of Pd nanorods, with high-index facets, a 106

Electrodeposition, CoPt nanowires, a 51

Electrodes, bottom, Ru, in DRAM capacitors, a 106

in Fuel Cells

Pd, EtOH oxidation, a 105

Pt, in dye sensitised solar cells 216

Electroless Plating, Cu, using a Pd-Sn catalyst, a 106

Pd films, on 316L stainless steel, a 52

Electroplating, Pd films, on 316L stainless steel, a 52

Emissions Control, a 50, 105, 175, 226

CO2 179

diesel 27, 37, 164, 174, 179, 226

gasoline 164, 179

motor vehicles, legislation, in Russia 98

vehicle 221

Engineering Stress-Strain Curve, Pd alloys 189

Engines, diesel 179

gasoline 179

αα,ββ-Enoic Acids, reduction 203

γγ,δδ-Enoic Acids, reduction 203

Enthalpy, PtC, PtH, PtN, PtO 123

Entropy, PtC, PtH, PtN, PtO 123


Page Page

Esters, α-arylation 183

reduction 203

α-vinylation 183

Ethane, steam reforming, a 175

Ethylene, adsorption, Pd-promoted zeolite 112

scavenger, Pd-promoted zeolite 112

1-Ethynyl-1-cyclohexanol, hydrogenation, a 50

Extraction, metals, conference 100

Films, FePt, oxidation behaviour, a 227

Pd, on 316L stainless steel, a 52

‘Final Analysis’ 55, 109, 179

Flame Spray Pyrolysis, one-step, nano-Pd/SiO2, a 175

Flame Synthesis, supported pgms 11

Formic Acid, electrooxidation, a 175, 227

fuel, for PEFC 58

generation of H2 78

oxidation 58

Four-Way Catalysts 27, 164

Fracture Strain, Pd alloys 189

PtRuGa 189

Fruit, climacteric, control of ethylene-induced ripening 112

Fuel Cells, a 51, 105, 175, 226–227

book reviews 172, 219

buildings 78

catalyst layers 219

catalysts, PtZn nanoparticles, a 227

cathodes, Pt, Pt alloys, DFT 147

conferences 78, 147

DEFC, electrocatalysts, a 51

electrodes, reaction mechanism, structural changes 147

DFAFC, anode catalysts, deactivation, reactivation, a 175

DMFC, anode catalysts 147

passive monopolar mini-stacks 147

portable electric power sources 147

vapour-fed 147

electrocatalysts 219

Pt-Au, surface characterisation, by XPS 55, 109

in Europe 78

fuel, processing 172

“Fuel Cell Today Industry Review 2009” 104

fuels 58, 78, 147, 172

membrane electrode assemblies 58

durability 147

MFC, anodes, cathodes, membranes 147

PEFC, anodes, electrocatalysts, a 51

Pt-Ru/Vulcan XC-72 C 58

cathodes, Pt/Vulcan XC-72 C 58

fuels, acetaldehyde, ethylene glycol, EtOH,

formaldehyde, formic acid, glycerol, MeOH,

1-propanol, 2-propanol 58

influence of NaCl vapour 147

liquid fuels 58

low pressure operation, using CO contaminated gas 147

MEAs, preparation 58

PEMFC, anodes 147

buildings 78

canal boat 78

catalyst layer degradation, XPS characterisation, a 175

catalyst layers 219

catalysts 147

cathode catalysts, using modelling aproach 147

CO-tolerant catalysts 219

electrocatalysts 219

electrodes 147

FlowCathTM

technology 147

H2 contamination, by Hg 147

high temperature 147

MEAs, by sieve printing method, a 226

by spray printing method, a 226

durability 147

reversal-tolerant catalyst layers 219

pgms, importance 40

SOFC, cathode, constant phase element, a 226

transport 78

Fuels, acetaldehyde 58

C-based 172

diesel 179

ethylene glycol 58

EtOH 58

formaldehyde 58

formic acid 58

gasoline 179

glycerol 58

H2, for fuel cells 58, 78, 147, 172

MeOH 58

processing 172

1-propanol 58

2-propanol 58

Gasoline, emissions control 164, 179

engines, downsized 179

Gibbs Energy, PtC, PtH, PtN, PtO 123

Glass, making, Pt equipment 40

Gluconic Acid, from glucose, a 50

Glucose, biosensor, a 227

selective oxidation, a 50

Grinding, Pt(5dpb)Cl, luminescence colour change, a 106

Hardness, Pd alloys 21, 189, 198

Pt 155, 198

Pt alloys 21, 155, 198

Heck Reactions, palladacycle catalysts 67

Pd/sepiolite, a 105

1-Heptyne, hydrogenation, a 175

1-Hexane, hydrogenation, a 50

High Temperature, Pt-based alloys 2, 69, 155

History, cisplatin, cancer drug 35

melting of Pt 209

Hydroacylation, alkenes, alkynes 86

Hydrocarbons, emissions, diesel 179


oxidative steam reforming 147

selective catalytic reduction 164

Hydrodechlorination, chlorinated ethenes, a 105

chloroarenes, in H2O, a 175

Hydroformylation, asymmetric 203

Hydrogen, absorption, Pd-Au nanoparticles, a 227

activation, Pd/C, Pt/C 135

borrowing, for formation of C–C, C–N 86

by exhaust gas reforming 221

by oxidative steam reforming 147

by photogeneration 45

+ CO, reduction of NOx, lean conditions, a 175

contamination, by Hg, for PEMFC 147

dissociative chemisorption, Pd/C, Pt/C, Rh/C 135

fuel, for fuel cells 58, 78, 147, 172

fuelling station requirements 78

generation 58, 78, 147

+ NO, + H2 164

photocatalysis 45

production 40

purification, Pd membranes 40

reduction, of NOx, on lean NOx traps, a 50

reduction of NOx, in O2-rich exhaust, a 175

sensors 147

storage 78

as NH3 147

uptake, Pd/activated C, a 176

vehicles 78

Hydrogen Peroxide, direct synthesis 221

Hydrogenation, alkenes, a 105

asymmetric 203

preparation of phenylalanines 203

in synthesis of sitagliptin 203

unsaturated C–C multiple bonds 203

asymmetric transfer, ketones 203

C5 olefin 221

catalyst additives 221

enantioselective, flame-made catalysts 11


Page Page

Hydrogenation, (cont.)1-ethynyl-1-cyclohexanol, a 50

flame-made catalysts 11

in H2O, a 226

1-heptyne, a 175

1-hexane, a 50

natural rubber latex, a 105

oximes 203

selective 11, 50

vapour-phase, citral, a 50

transfer 78

Hydrometallurgy, conference 100

Hydroprocessing, C supported catalysts 135

Imines, formation 86

reduction 203

Inkjet Printing, Pd-Sn colloids, a 106

Ionic Liquids, catalyst preparation, a 105

solvent, a 176

in solvent extraction 100

Iridium, arc melting 209

electron beam melting 209

melting 209

polycrystalline, defect structure 138

high purity 138

plastic deformation 138

single crystals 138

Iridium Alloys, Pt-Al-Ir, high temperature 2

Pt-10%Ir, investment casting 21

with Re and Ru 138

Iridium Complexes, dye sensitised solar cells 216

Ir(III), octahedral, photophysical properties 45

spectroscopic properties 45

OLEDs 45

Ir(III) fluorenone-ppy, electrophosphorescence, a 176

Ir(III) phenylpyridines, solar cells, a 52

Iridium Compounds, IrB1.35, hard, hardness, a 176

Jewellery, CAD/CAM 21, 198

mokume gane 198

Pd 198

Pd alloys 21, 189, 198

Pt, bench-scale repair, using blowpipes 209

lasers, manufacture, repair 21

manufacture 21, 198

Pt alloys 21, 189, 198

Johnson Matthey, autocatalyst production, Russia 98

catalysts 183, 203

ethylene scavanger 112

melting of Pt 209

“Platinum 2008 Interim Review” 48

“Platinum 2009” 174

ββ-Keto Esters, reduction 203

Ketones, aryl, reduction 203

asymmetric transfer hydrogenation 203

α-vinylation 183

Lasers, Pt jewellery, manufacture, repair 21

Lattice Misfits, Pt86Al10Z4, Z = Cr, Ir, Ru, Ta, Ti 69

Leaching, catalysts, for new catalytic reactions, a 105

Lean NOx Traps 37, 164

regeneration with H2, a 50

Liquid Crystals, palladacycles 67

Luminescence, colour change, grinding, Pt(5dpb)Cl, a 106

Pt octaethylporphyrin, a 51

Magnetism, CoPt nanowires, a 51

FePt-γ-CD, a 226

Markets, precious metals 40

MEAs, durability, in PEM fuel cells 147

preparation 58

Mechanical Properties, Pt-based ternary alloys 2

Melting, PdGaIn, arc melting, under Ar 198

pgms, history 209

Melting, (cont.)arc melting, electron beam heating, induction heating 209

Membranes, Pd, H2 purification 40

Pd81Pt19, D2 permeation, a 51

Metallurgy and Materials, a 51, 105–106, 176, 227

Metals Extraction, conference 100

Methane, + NO2 164

combustion 11

internal reforming 147

partial oxidation 11

steam reforming, a 175

Microwaves, synthesis of Pd-Pt/C, for PEMFC 147

Mokume Gane, jewellery 198

Nanocomposites, Pt nanoparticles/C MWNTs, a 227

Nanoflakes, Pd–PdO core–shell, on Pt, a 105

Nanoflowers, Pt, a 227

Nanoparticles, Corich core-Ptrich shell, a 175

FePt, a 226, 227

nano-Pd/SiO2, a 175

particulate matter 27

patchy, CdS/PdxCdyS/CdS, PdSx/Co9S8, a 106

Pd 50, 67, 105, 175, 176

PVP-protected, a 227

Pd on Au, a 105

Pd-Au, a 227

Pd-polymer (DNA) hybrid 147

PdRu 147

Pt, a 51, 175, 227

PtZn, a 227

Rh, a 175

RhOx, a 175

Nanorods, Pd, a 106

Nanowires, CoPt, a 51

Natural Gas, steam reforming, a 175

Nitrogen Oxides, NO, + H2, + O2 164


NO

2

, + CH4 164

NOx, control catalysts 27

emissions, diesel 164, 179

lean, reduction, by CO, H2, a 175

traps 37

regeneration with H2, a 50

reduction 50, 164

by H2, in O2-rich exhaust, a 175

removal, a 50

from diesel exhaust 221

under a lean/rich atmosphere, a 226

selective catalytic reduction 27, 179

storage 164

catalysts, model 164

storage-reduction 11

traps, diesel 179

lean 164

catalysts, S removal 164

thermal ageing 164

NMR,

31P, Pd(OAc)2 + dppf, a 106

NOx Storage and Reduction 164, 226

OLEDs, Ir(III), Os(II), Pt(II) complexes 45

Olefins, C5, hydrogenation 221

dihydroxylation, a 50

Osmium, higher-order elastic constants 91

sound velocity 91

ultrasonic attenuation coefficients 91

ultrasonic velocity 91

Osmium Complexes, Os(II), OLEDs 45

[Os(L–L)2(N–N)]2+

, phosphorescence, a 106

[Os(N–N)2(L–L)]2+

, phosphorescence, a 106

photoinduced electron-transfer 45

photoinduced energy-transfer 45

Oxidation, aerobic, alcohols, in H2O, a 175

by flame-made catalysts 11

CO, in diesel exhaust, a 226

electro-, EtOH, a 106


Page Page

Oxidation, (cont.)formic acid, a 175, 227

MeOH, a 227

EtOH 58, 105

FePt nanoparticles, a 227

formic acid 58

HC, in diesel exhaust, a 226

isothermal, Pt-Al-Z, Z = Cr, Ir, Re, Ru, Ta, Ti 2

Pt86:Al10:Z4, Z = Cr, Ir, Ru, Ti 2

MeOH, a 227

NO, in diesel exhaust, a 226

partial, CH4 11

particulate matter 27

Pt-based ternary alloys 2

selective, CO 11

glucose, a 50

Oximes, hydrogenation 203

Oxygen, + CO 221

reduction reaction, a 175

sensors, a 51

Palladacycles, anticancer 67

applications 67

catalysts, for cross-coupling reactions 67

characterisation 67

Hermann’s 67

liquid crystals 67

photophysical properties 67

synthesis 67

thermal stability 67

Palladium, electrodes, EtOH oxidation, a 105

films, electroless plated, on 316L stainless steel, a 52

electroplated, on 316L stainless steel, a 52

high temperature interface reaction, SiC, TiC, TiN, a 105

jewellery 198

melting 209

membranes, H2 purification 40

nanocrystalline, H2 uptake, a 176

nanoparticles 50, 67, 105

PVP-protected, a 227

nanorods, electrochemical preparation, a 106

with high-index facets, a 106

particles, dispersed over zeolite 112

Pd/activated C fibre, H2 uptake, a 176

Pd-on-Au nanoparticles, a 105

Pd nanoparticles/microporous activated C, H2 uptake, a 176

Pd–PdO core–shell nanoflakes, on Pt, a 105

Pd-polymer (DNA) hybrid nanoparticles, H2 sensors 147

Pd-promoted zeolite, ethylene adsorption 112

ethylene scavenger 112

Pd-Sn colloids, catalyst, electroless Cu metallisation, a 106

inkjet printing, a 106

Palladium Alloys, 950, burnishing, hardness, surface 198

investment casting 198

for jewellery 21, 189, 198

mokume gane 198

AuPdCu, fracture strain 189

hardness 189

tensile strength 189

yield strength 189

fusion of coloured ceramic overlays 189

hardness 21, 189, 198

investment casting 21, 198

jewellery 21, 189, 198

MgPd, from Mg6Pd, a 176

Mg6Pd, preparation, hydriding, a 176

Pd950G, Pd-Ga-Ag-In, casting 21

scrap, recycling 21

Pd-Ag-based, dental 21

950 Pd-Ag-Ga-Cu, casting 21

Pd95.5Al1.9Mg2.6, hardness 189

Pd95.5Al3.8Mg0.7, hardness 189

PdAlRu, mechanical behaviour 189

Pd95.5Al0.9Ru3.6, annealed, eng. stress-strain curves 189

XRD pattern 189

Palladium Alloys, (cont.)colour 189

density 189

fracture strain 189

hardness 189

Poisson’s ratio 189

ultimate tensile strength 189

workability 189

yield strength 189

Young’s modulus 189

Pd95.5Al2.8Ru1.7, annealed, eng. stress-strain curves 189

colour 189

density 189

fracture strain 189

hardness 189

Poisson’s ratio 189

ultimate tensile strength 189

workability 189

yield strength 189

Young’s modulus 189

Pd95.5Al0.4Ti4.1, hardness 189

Pd95.5Al1.3Ti3.2, hardness 189

Pd-Au nanoparticles, H2 absorption, a 227

PdCu, hardness 189

PdGa, hardness 189

PdGaIn, arc melting, under Ar 198


Pd-In, thermochemistry, a 51

Pd74.0-In5.0-Cu14.5Ga1.6Sn4.9, dental 21

950 Pd-Nb-Ga 21

Pd81Pt19 membrane, D2 permeation, a 51

PdRu, fracture strain 189

hardness 189


yield strength 189

950 Pd-Ru-Ga, casting 21

Pd-Sn, thermochemistry, a 51

Pd-Zn, thermochemistry, a 51

watchmaking 189

Palladium Complexes, PCP-pincer Pd hydride–

K-Selectride®

, a 52

(PCP)i-Pr

PdCl + K-Selectride®

, a 52

Pd(II), recovery, from HCl, in presence of Pt(IV),

using S-containing monoamide, diamide 100

solvent extraction, pyridine carboxamide and

phosphonium ionic liquid systems 100

copolymers, N-isopropylacrylamide and thioethers 100

Pd(II) chloro, solvent extraction, tren polyamines 100

[Pd(dppf)(OAc)2], 31

P NMR, a 106

Pd(II) fluorinated benzoporphyrins, phosphorescence, a 106

Pd(II)-functionalised diphosphines, H2O soluble, a 176

Pd2+

+ G4.5-COOCH3 PAMAM dendrimers, a 176

Pd β-ketoiminates, CVD precursors, a 227

Pd(OAc)2 + dppf, 31

P NMR, a 106

Pd(OAc)2 + functionalised diphosphine, a 176

Pd(PPh3)2Cl2/ethylene-bridged dithiosemicarbazones, a 227

/phenylene-bridged dithiosemicarbazones, a 227

Pd(II) salicylaldimine dithiosemicarbazones, a 227

solvent extraction, using hydroxyoxime LIX 84I 100

using malonamide DMDOHEMA 100

tetrakis(triphenylphosphine)palladium, precusor, a 50

Palladium Compounds, MgD2, by hydrogentation, a 176

nanoparticles, patchy, CdS/PdxCdyS/CdS, PdSx/Co9S8, a106

palladacycles, see Palladacycles


PdHx, destabilisation, a 176

Particles, nanosized, Zn2PtO4, a 51

Pd, dispersed over zeolite 112

Particulate Matter, emissions, diesel 27, 179

Patents 53–54, 107–108, 177–178, 228–229

Permeation, D2, Pd81Pt19 membrane, a 51

Phase Diagrams, Pt-Al-Co, Pt-Ni-Ru 155

Phenylalanines, by asymmetric hydrogenation 203

Phosphines, pgm complexes, in catalysis 203

Phosphorescence, electro-, Ir(III) fluorenone-ppy, a 176


Page Page

Phosphorescence, (cont.)Pt(II) fluorenone-ppy, a 176

NIR, Pd(II) with fluorinated benzoporphyrins, a 106

Pt(II) with fluorinated benzoporphyrins, a 106

[Os(L–L)2(N–N)]2+

, [Os(N–N)2(L–L)]2+

, a 106

Photocatalysis 11

Ru complexes 45

sterilisation of Escherichia coli, a 226

Photochemistry, pgm complexes 45

Photoconversion, a 52, 106, 176

Photophysical Properties, palladacycles 67

Photophysics, pgm complexes 45

Photoproperties, pgm complexes 45

Photosynthesis, ‘artificial’, Ru complexes 45

Platinum, arc melting 209

availability 40

coating, Si AFM probes, a 52

corrosion, Cl2-induced, a 176

electrodes, in dye sensitised solar cells 216

electron beam heating 209

equipment, glass industry 40

FePt film, oxidation behaviour, a 227

FePt nanoparticles, oxidation behaviour, a 227

hardness 155, 198

induction heating 209

industrial casting 209

jewellery, lasers, manufacture, repair 21

manufacture 21, 198

melting 209

nanoflowers, a 227

nanoparticles, a 51


Pt nanoparticle–graphene composite, a 51

Pt nanoparticles/C MWNTs, glucose biosensor, a 227

segregation, in FePt nanoparticles, a 227

stress-rupture curve 2

thin films, on SiO2 particles, by barrel sputtering, a 52

ZGS, stress-rupture curve 2

Platinum Alloys, 950, burnishing, hardness, surface 198


jewellery 21, 198

casting, effect of CAD/CAM-derived materials 21

colour 189

CoPt nanowires, electrodeposition, a 51

magnetic properties, microstructural properties, a 51

hardness 21, 155, 189

investment casting 21, 198

jewellery 21, 189, 198

Pd81Pt19 membrane, D2 permeation, a 51

Pt-Al, high temperature 2

Pt85:Al15, in situ high temperature TEM 69

Pt86Al14, Pt3Al precipitate, TEM 69

Pt-Al-Co, hardness 155

phase diagram 155

Pt-Al-Co-Cr-Ru, hardness 155

Pt-Al-Cr, high temperature 2

Pt86:Al10:Cr4, tensile testing 155

Pt79.5:Al10.5:Cr5.5:Ru4.5, Vickers hardness 155

Pt80:Al14:Cr3:Ru3 155



Pt83:Al11:Cr3.5:Ru2.5, Vickers hardness 155

Pt84:Al11:Cr3:Ru2, oxidation resistance 155

tensile testing 155

Pt84:Al11.5:Cr2.5:Ru2, Vickers hardness 155

Pt85:Al11:Cr2:Ru2, Vickers hardness 155

Pt-Al-Ir, high temperature 2

Pt86:Al10:Ir4, in situ high temperature TEM 69

stable precipitates 69

Pt-Al-Ru, high temperature 2

Pt86:Al10:Ru4, tensile testing 155

Pt-Al-Z, Z = Cr, Ir, Mo, Ni, Re, Ru, Ta, Ti, W 2

Pt-Al-Z, Z = Cr, Ir, Re, Ru, Ta, Ti, isothermal oxidation 2

Pt-Al-Z, Z = Cr, Ir, Ru, Ta, Ti, Pt3Al precipitate, TEM 69

TEM 69

Platinum Alloys, (cont.)Pt86:Al10:Z4, Z = Cr, Ir, Ru, stress-rupture curves 2

Pt86Al10Z4, Z = Cr, Ir, Ru, Ta, Ti, dislocation interactions 69

lattice misfits 69

precipitates 69

Pt-10%Ir, investment casting 21

Pt-Nb-Ru 2

Pt-Ni-Ru, phase diagram 155

Pt-Rh, stress-rupture curve 2

PtRu, colour 189

PtRuGa, fracture strain 189

hardness 189


yield strength 189

Pt-Ta-Re 2

Pt-Ta-Ru 2

Pt-Ti-Re 2

Pt-Ti-Ru 2

ternary, mechanical properties 2

oxidation 2

Platinum Complexes, in a chloride matrix, solvent

extraction, using Amberlite LA-2 100

[(COD)PtCl2] + LiN(SiMe3)2, a 52

[COD]PtClN(SiMe3)2, for PXP Pt pincer complexes, a 52

dye sensitised solar cells 216

Pt(II), OLEDs 45

square-planar, OLEDs 45

photochemistry 45

photophysics 45

Pt(IV), in HCl 100

Pt(II) chloro, solvent extraction, tren polyamines 100

[PtCl6]2–

, solvent extraction, using tripodal amido and

urea group-based anion-binding ligands 100

Pt–DNA adducts, a 227

Pt(dpb)Cl, luminescence colour change, grinding, a 106

Pt(5dpb)Cl, luminescence colour change, grinding, a 106

[Pt(dpma)Cl]+, substitution reaction with thioacetate, a 176

Pt(II) fluorenone-ppy, electrophosphorescence, a 176

Pt(II) fluorinated benzoporphyrins, phosphorescence, a106

Pt octaethylporphyrin, luminescence, a 51

O2-sensitive, a 51

[2(trenH4)4+·(PdCl4)

2–

·4Cl–

·H2O], isolation 100

Platinum Compounds, antitumour, a 227

cisplatin, anticancer drug 35

platinum salts, chemotherapy agents, for cancer 35

PtC, PtH, PtN, PtO, thermodynamic properties 123

PtCl4, from interaction of Cl2 with Pt(110), a 176

Pt silicide, formation, on Pt-coated Si AFM probes, a 52

Zn2PtO4, nanosized, a 51

Platinum Group Metals, analysis, using Analig®

40

demand, in autocatalysts, effect of CO2 legislation 179

melting 209

recycling 40

refining 40

Poisson’s Ratio, PdAlRu alloys 189

Precious Metals, conference: analysis, economics,

markets, process technologies, recovery, refining,

regulations, sampling 40

Propane, steam reforming, a 175

Racemisation, secondary alcohols 203

Recovery, Pd(II), from HCl, in presence of Pt(IV) 100

precious metals, from catalysts, plasma heater reactors 40

from combustible waste, using ‘The Ox’ 40

from refinery catalysts, by treatment in PlasmaEnvi®

40

Recycling, autocatalysts 40

Pd jewellery alloys 21

Reduction, aryl ketones 203

asymmetric, (Z)-acetamidocinnamic acid methyl ester 203

unfunctionalised alkenes 203

dehydroamino acids 203

enamides 203

α,β-, γ,δ-enoic acids 203

esters 203

imines 203


Page Page

Reduction, (cont.)itaconates 203

β-keto esters 203

NOx 164

with H2, a 50

Refining, JSC Krastsvetmet 40

Refining and Recovery, pgms 100

precious metals 40

Reforming, autothermal, C-based fuels 172

C-based fuels 172

exhaust gas 221

internal, CH4 147

oxidative steam, hydrocarbons 147

pre-, C-based fuels 172

steam, butane, a 175

C-based fuels 172

ethane, a 175

methane, a 175

natural gas, a 175

propane, a 175

Regulations, precious metals 40

Rhodium, arc melting 209

assaying 40

electron beam melting 209

high temperature interface reaction, SiC, TiC, TiN, a 105

melting 209

Rhodium Alloys, Pt-Rh, stress-rupture curve 2

Rhodium Complexes, photophysics 45

[(PNP)Rh(CN)] + EtI, a 52

[(PNP)Rh(CN)] + MeI, a 52

[(PNP)Rh(CN)(CH3)][I], reactions, a 52

Rh(III) bipyridines, photoproperties 45

Rh(III) chloro, solvent extraction, tren polyamines 100

Rh(III) cyclometallates, photoproperties 45

Rh(III) polypyridines, photoproperties 45

Rh(III) terpyridines, photoproperties 45

Rhodium Compounds, RhB1.1, hard, hardness, a 176

Rubber, natural latex, hydrogenation, a 105

Russia, new autocatalyst production facility 98

Ruthenium, bottom electrodes, in DRAM capacitors, a 106

chemical mechanical planarisation slurry, a 106

higher-order elastic constants 91

sound velocity 91

ultrasonic attenuation coefficients 91

ultrasonic velocity 91

Ruthenium Alloys, with Ir and Re 138

with Pd, see Palladium Alloys

with Pt, see Platinum Alloys

Ruthenium Complexes, ‘artificial photosynthesis’ 45

black dye, dye sensitised solar cells 216

CYC-B1, with an alkyl bithiophene group, solar cells, a 52

dendrimeric 45

dye sensitised solar cells 45, 216

K20 dye, dye sensitised solar cells 216

modified dyes, dye sensitised solar cells 216

multinuclear 45

N3 dye, dye sensitised solar cells 216

N719 dye, dye sensitised solar cells 216

photocatalysis 45

photogeneration, of H2 45

polymeric 45

Ru(III) chloro, solvent extraction, tren polyamines 100

Ru(II) polypyridines, basic properties 45

supramolecular assemblies 45

Ruthenium Compounds, RuO2·2H2O, RuO4, in Ru

chemical mechanical planarisation, a 106

Scavenger, Pd-promoted zeolite, of ethylene 112

Selective Catalytic Reduction, catalysts 37

CO 164

hydrocarbons 164

NH3 164

NOx 27, 179

Sensors, bio-, glucose, a 227

catalytic, precious metals 40

Sensors, (cont.)supported pgms, by flame synthesis 11

combustible gases 40

H2 147

O2, a 51

Single Crystals, iridium 138

Solar Cells, dye sensitised, Ir complexes 52, 216

Pt complexes 216

Ru complexes 45, 52, 216

Solvent Extraction, Pd, using hydroxyoxime LIX 84I 100

using malonamide DMDOHEMA 100

Pd(II), pyridine carboxamide and phosphonium ionic

liquid systems 100

copolymers of N-isopropylacrylamide and thioethers 100

Pd(II) chloro, using tren polyamines 100

Pt, in a chloride matrix, using Amberlite LA-2 100

[PtCl6]2–

, using tripodal amido and urea group-based

anion-binding ligands 100

Pt(II) chloro, using tren polyamines 100

Rh(III) chloro, using tren polyamines 100

Ru(III) chloro, using tren polyamines 100

Sonogashira Couplings, palladacycle catalysts 67

Soot, removal, a 50

Sound Velocity, Os 91

Ru 91

Specific Heat Capacity, PtC, PtH, PtN, PtO 123

Sputtering, barrel, Pt thin films, on SiO2 particles, a 52

reactive, of PdO, on Pt, a 105

Stress-Rupture, Pt 2

Pt86:Al10:Z4, Z = Cr, Ir, Ru 2

Pt-Rh 2

ZGS Pt 2

Sulfur, effect of, on diesel oxidation catalysts, a 105

removal, from lean NOx trap 164

Sulfuric Acid, production 40

Surface Coatings, a 52

Suzuki Couplings, palladacycle catalysts 67

sterically bulky aryl bromides 183

Syngas, production 11

Tamiflu

®®, synthesis, a 226

Thermochemistry, Pd-In, a 51

Pd-Sn, a 51

Pd-Zn, a 51

Thermodynamic Properties, PtC, PtH, PtN, PtO 123

Thin Films, Pt, on SiO2 particles, by barrel sputtering, a 52

Three-Way Catalysts 11, 27

Ultimate Tensile Strength, PdAlRu alloys 189

Ultrasonic Attenuation Coefficients, Os 91

Ru 91

Ultrasonic Velocity, Os 91

Ru 91

Vinyl Selenides, cyclic, synthesis, a 105

Vinyl Sulfides, cyclic, synthesis, a 105

αα-Vinylation, carbonyl compounds 183

esters 183

ketones 183

Watchmaking, Pd alloys 189

Water, remediation, hydrodechlorination, a 105

solvent, a 175, 176, 226

XPS, catalyst layer, PEM fuel cells, a 175

surface characterisation, heterogeneous catalysts 55, 109

Pt-Au fuel cell catalyst 55, 109

qualification of elements 109

Yield Strength, Pd alloys 189

PtRuGa 189

Young’s Modulus, PdAlRu alloys 189


Page Page

EDITORIAL TEAM

EditorDavid Jollie

Assistant EditorSara Coles

Editorial AssistantMargery Ryan

Senior Information ScientistKeith White

E-mail: [email protected]

Platinum Metals Review is the quarterly E-journal supporting research on the science and technology of the platinum group metals and developments in their application in industry

http://www.platinummetalsreview.com/

Platinum Metals ReviewJohnson Matthey Plc, Precious Metals Marketing, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K.

E-mail: [email protected]://www.platinummetalsreview.com/

platinum metals review - technology.matthey.comapplications of the pd(i) dimer in organic synthesis...

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