,“I@DOE/Ojfice of Industrial Technology

Sponsored byw

Laboratory Coordinating Council

@ Sandia National Laboratories

,.

. .

DOE LaboratoryCatalysis Research

Symposium

RU5D21W

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February 24-25, 1999

Wyndharn l-lote/

Albuquerque, NM

—...——.— .

Thk workof authorshipwas preparedas an accountof worksponsoredby an agencyof the UnitedStatesGovernment.Accordingly,the UnitedStatesGovernmentretainsa nonexclusive,royaky-tkeelicenseto publishor reproducethe publishedformof this contribution,or allow others todo so for UnitedStates Governmentpurposes. Neither SandiaCorporation,the UnitedStates Govemmen~nor any agencythereof nor any oftheir employeesmakes any warranty,express or implied, or assumes any legal IiaMIityor responsibilityfor the accuracy,completeness,orusefidnessof any information,apparatus,produc~ or process disclosed,or representsthat its use would not infihge privately-ownedrights.Reference herein to any specific commercialproduct process, or service by trade name, trademark manufacturer,or otherwise does notnecessarilyconstituteor imply its endorsemen~recommendation,or favoringby Sandia CorporatiorLthe United States GovemmenLor anyagency thereof. The views and opinions expressedherein do not necessarilystate or reflect those of Sandia Corporation,the United StatesGovernmentor any agencythereof.

Sandiais a mrdtiprograrrrlaboratoryoperatedby SandiaCorporation,a LockheedMartinCompany,for the UnitedStatesDepartmentof EnergyundercontractDE-AC04-94AL85000.

.

DISCLAIMER

Portions of this document may be illegiblein electronic image products. Images areproduced from the best available originaldocument.

... .

DOE Laboratory Catalysis Research SymposiumSponsored by DOE/EE/OIT, OIT Lab Coordinating Council& Sandia National Laboratories

The Dutch have NIOK (Netherlands Institute of Catalysis). The

British have iAc (Institute ofApplied Catalysis). What do UScatalysis researchers have to oj$er their industrial and government

customers? Can we compete e~ectively with our Europeancolleagues in the increasingly global marketplace of the chemicalandpetroleum industries? Are we maximuing our govemment-supported catalysis research dollars? Interested in investigating intoa change in the US catalysis research paradigm?

February 24,1999

Dear Catalysis Symposium Participants:

Welcome to the DOE Laboratory Catalysis Research Symposium, the first technical meeting focussedsolely on catalysis researchers at the US DOE national laboratories. I hope that your attendance at theSymposium indicates your interest in exploring the possibilities for a more formal US catalysisresearch community. During our business meeting on Wednesday, February 24, we will be addressingways in which we can work together more efficiently. As we will learn at this meeting, other

countries, particularly our European colleagues, value catalysis highly and are establishing effectivecatalysis research virtual organizations. We will consider what, if any, should be the US response.

Many thanks to our sponsors . . .DOE Office of Industrial Technologies,

Amy Manheirn, Catalysis Program Manager, for financial supportOIT Lab Coordinating Council

Steve Weiner, LCC Chair, and all the LCC members for providing financial support for ourkeynote speaker and for disseminating the symposium invitation and information to all theirappropriate laboratory personnel

SandiaNational LaboratoriesFor staff support for the meetings arrangement coordinator and the conference chair

We are very fortunate to have an excellent keynote speaker. Chris Adams is Director of the UKInstitute of Applied Catalysis (iAc). I had the privilege of learning about the iAc and Chris’ leadershipof this relatively new organization fnst hand when I visited the UK last fall. The UK Foresightprogram, which is similar to the US Vision 2020 chemical roadmapping exercise, identified “catalysisas the central technology to secure wealth generation and environmental sustainability for the UKchemicals industry of the next century.” I know that we in the US will find his talk about the iAc to

be insightful and highly relevant.

lqfTY-Nancy B. Jacks

I

Sandia National Laboratories

DOE Laboratory Ca[aIysis Reseaxh Sjmposium(

.—.—

Sessions

Heterogeneous Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Novel Catalytic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...12Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...14NovelProcesshg Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...16Metals&Sulfides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -..17NuclearMagnetic Resonance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...19Metal Oxides and Partial Oxidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...20Electrocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...24Automotive Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...25

Homogeneous Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-27H-Transfer &Alkane Functionalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...28Biocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - - . - --.-.-.30Oxidation &Photocatalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...32Novel Media. Methods. &Catalyzed Reactions . . . . . . . . . . . . . . . . . . . . . . . . ...33

Poster Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -.......35

IndexbyPresenter

Presenter Page

(+brams, M. B.,LANL . . . . . . . . . . . . . . . ...48Bakac, A., AMES . . . . . . . . . . . . . . . . . . . ...32Baker, R. T., LAND . . . . . . . . . . . . . . . . . ...34Bartley, G. J. J., Southwest Research Inst. . ..42Blake, D. M., NOEL . . . . . . . . . . . . . ..15&45Bullock, R. M., BNL . . . . . . . . . . . . . . . . ...28Camaioni, D. M., PNNL . . . . . . . . . . . . . ...29Carrado, K. A.,ANL . . . . . . . . . . . . ...12&41Carter, C.A. G.,LANL . . . . . . . . . . . . . . ...49Darab, J. G., PNNL . . . . . . . . . . . . . . . . . ...13Datye. A. K., UNM . . . . . . . . . . . . . . . . . ...44de Rege, F. M., LAND . . . . . . . . . . . . . . . ...48Dien, L., LAND . . . . . . . . . . . . . . . . . . . . ...43Dubois, D., NOEL . . . . . . . . . . . . . . . . . . ...24Elam, C., NREL . . . . . . . . . . . . . . . . . . . . ...42Elder, S. H., PNNL . . . . . . . . . . . . . . . . . . ...14Elliott, D. C., PNNL . . . . . . . . . . . . . . . . . ...16Ellis, P. D., PNNL . . . . . . . . . . . . . . . . . . ...19Fish, R. H., LBNL . . . . . . . . . . . . . . . ..298z51Fremgen, D. E.,ANL . . . . . . . . . . . . . . . . ...51Fujita, E., BNL . . . . . . . . . . . . . . . . . . . . . ...32Gardner, T. J., SOL . . . . . . . . . . . . . . ..138.z46Ginosar, D. M., lN_EEL . . . . . . . . . . . . . . ...16Gutowski, M., PNNL . . . . . . . . . . . . . . . . ...21Hay, P. J., LANL . . . . . . . . . . . . . . . . . . . ...37Henson, N. J., LAND . . . . . . . . . . . . . . . . ...40

Hijar, C. A., LAND . . . . . . . . . . . . . . . . . ...37

Himmel, M. E., NREL . . . . . . . . . . . . . . . . ..3lHrbek, J., BNL . . . . . . . . . . . . . . . . . . . . . ...18Jackson, N. B., SOL . . . . . . . . . . . . . ..17A41Jacobson, G. B.,LANL . . . . . . . . . . . . . . ...52

Presenter . Page

Josephsohn,N., LAND . . . . . . . . . . . . . . . ...52Kerr, J. B., LBNL . . . . . . . . . . . . . . . . . . . ...30Klingler, R.J.,ANL . . . . . . . . . . . . . . . . . ...33Konze, W. V., LAND . . . . . . . . . . . . . . . . ...49Kubas, G. J., LAND . . . . . . . . . . . . . . . . . ...50Labounau,A.,LANL . . . . . . . . . . . . . . . . ...37

Liang, Y., PNNL . . . . . . . . . . . . . . . . . . . ...43Lin, M. S., BNL . . . . . . . . . . . . . . . . . . . . ...30Ma=qini, K., NOEL . . . . . . . . . . . . . ...14&240Mahajan, D., BNL . . . . . . . . . . . . . . . . . . ...34Mansker, L. D.,UNM . . . . . . . . . . . . . . . ...45Marshall,C.L.,ANL . . . . . . . . . . . . ., . . . ...18Martin, R. L., LAND . . . . . . . . . . . . . . . . ...28Miller, J. E., SOL . . . . . . . . . . . . . . . ..228z48Mullins, D, R., ORAL . . . . . . . . . . . . . . . ...25Nicholas,J.B.,PNNL . . . . . . . . . . . . . . . ...20Orlando, T. M., PNNL . . . . . . . . . . . . . . . ...23Ott, K. C.,LANL . . . . . . . . . . . . . . . . ..218z38Paffett, M., LANL . . . . . . . . . . . . . . . . . . ...23Peden, C. H. F.,PNNL . . . . . . . . . . . ..26tk47Peters, R. G., LA.NL . . . . . . . . . . . . . . . . . ...50Pietrassii,T.,NMI . . . . . . . . . . . . . . . . . . ...38Redondo, A., LAND . . . . . . . . . . . . . . . . . ...20Reynolds,J. G., LLNL . . . . . . . . . . . . . . . ...25Rodriguez,J.A.,BNL . . . . . . . . . . . . .17d244Sault, A. G., SNL . . . . . . . . . . . . . . . . . . . ...39

Tumas, W., LANL . . . . . . . . . . . . . . . . . . ...33

Tumrnala,S.,LANL . . . . . . . . . . . . . . . . . ...46Wang, Y.,PNNL . . . . . . . . . . . . . . ...12&47Xue, Z. Y., AMES . . . . . . . . . . . . . . . . . . ...39Zerkle, D. K., LAND . . . . . . . . . . . . . . . . ...22

4

DOE Laboratory Catalysis Research SymposiumCoordinating Committee

Conference ChairNancy Jackson, Sandia National Laboratories

Technical CommitteeTom Baker, Los Alarnos National LaboratoryCharles Peden, Pacific Northwest National LaboratoryAllen Sault, Sandia National Laboratories

Meeting Arrangements CoordinatorTracy Dunham, Sandia National Laboratories

Session ChairsAileen Alvarado-Swaisgood, MSIRick Kemp, Union CarbideTyler Thompson, Dow ChemicalJohn Reynolds, LLNLTechnical Committee & Chair

— ..—--- .—

Agenda

DOE Laboratory Catalysis Research SymposiumFebruary 24-25,2999

Albuquerque, NM

Grand Quivira Room

7:30-8:30 Registration & Continental Breakfast

8:30-8:45 Welcoming Remarks, Nancy Jackson, Sandia National Labs8:45-9:45 Keynote Speaker - Professor Chris Adams, Institute of Applied Catalysis, UK

9:45-10:00 Break

Heterogeneous Catalysis (Vane Grande II)

Novel Catalytic Materials

10:00-10:25 K. Carrado, ANL, Preparation and Characterization of Mesoporous Synthetic Clays10:25-10:.50 Y. Wang, PNNL, Mesoporous Silica Supported Solid Acid Catalysts10:50-11:15 T. Gardner, SNL, Synthesis, Characterization, and Testing of Novel Hydrous Metal Oxide-

Supported Catalyst Materials11:15-11:40 J. Darab, PNNL, Nano-Crystalline Particulate Catalyst and Catalyst Support Materials Generated

Using A Flow-Through Hydrothermal Process

11:40 – 1:15 Lunch – Provided & Business Meeting

PhotocataIysis

1:15-1:40 S. Elder, PNNL, The Synthesis of New Nanocyrstalline MoXTil.xOzMaterials with TailoredPhotophysical Properties

1:40-2:05 K. Magrini, NREL, Application of Solar Photocatalytic Oxidation to VOC-Containing Airstreams2:05-2:30 D. Bkzke, NREL, Photocatalytic Cell Killing and Oxidation of Whole Cells in Contact with

Illuminated Titanium Dioxide Su@aces

NoveI Processing Conditions

2:30-2:53 D. Ginosar, INEEL, Alkylation of Aromatics at Supercritical Fluid Conditions2:55-3:20 D. Elliott, PNNL, Development of Heterogeneous Catalysis for Use in Aqueous Phase Processing

Metals and Sulfides

3:354:00 N. Jackson, SNL, Attrition-related Morphology Changes in Iron Fischer-Tropsch Catalysts4:004:25 J. Rodriguez BNJ.-,Characterization of Oxide Catalysts using Synchrontron-Based Time-Resolved

X-ray Absorption Spectroscopy (xAS)4:25-4:50 C. Marshall, ANL, Improved Catalysts for the Removal of Sulphurfrom Heavy Hydrocarbons4:50-5:15 J. Hrbek, BNL, Macroscopic and Atomistic View of Suljiur Interactions with Model Bimetallic

Catalysts

Homogeneous Catalysis (Vane Grande 1)

H-Transfer and Alkane Functionalization

10:00-10:25 R. M. Bullock, BNL, Hydride Transfer and Hydrogen Atom Transfer Reactions of Transition MetalHydrides – Kinetic and Mechanistic Studies

10:25-10:50 R. Mardn, LANL, DensiQ Functional Theoq Studies of C-H Activation in Cationic OS(H) andPt(II) Complexes

10:50-11:15 R. Fish, LBNL, Flourous Biphasic Catalysis: A New Paradigm for the Separation of HomogeneousCatalysts from Their Reaction Substrates and Products, as Demonstrated in Alkane and AlkeneFunctionalization Chemistq

6

11:15-11:40 D. Camaion4PNNL, Radical Pathways for Selective Oxidation of Alkmes in Trij7uoroacetic Acid

11:40-1:15 Lunch - Provided & Business Meeting

Biocatalysis

1:15-1:40 J. Kerr, U3NL, Biomimetic Catalysis of Enzyme Co-factor Regeneration with [Cp*Rh(bipy)H]+ andNAD+Models: Mechanistic Aspects, Deactivation, Reaction Rates, and Economic Factors

1:40-2:05 M. Lin, BNL, Recent Advances in Biocatal~sis of Fossil Fuels2:05-2:30 M. E. Himmel, NREL, Protein Engineering for Bioethanol Production

Oxidationand Photocatalysis

2:30-2:55 A. Bakac, Ames, Catalytic Oxidation Accelerated By a Built-in Chain Cycle2:55-3:20 E. Fujita, BNL, Photochemical Water and Carbon Dioxide Reduction with Metal Complexes

3:20-3:35 Break

Novel Media, Methods, and Catalyzed Reactions

3:35-4:00

4:00-4:254:25-4:504:50-5:15

6:00-8:008:00-10:00

W. Tumas, LANL, Catalysis and Chemical Synthesis In Dense Phase Fluids: Towards SolventReplacement and Enhanced SelectivityR. Klingler, AM+ High-Pressure NMR Studies of Supercritical HydroformylationsD. Mahajan, BNL, Homogeneously Catalyzed Selective Synthesis of Methanol@om Synthesis GasR. T. Baker, LANL, Metal-Catalyzed Deoxyoligo-merization of Carbonyl Compounds usingDiboron Reagents

Poster Session Bandelier Room – Cash BarDinner (Tijeras Room) - Speaker - Roy Penana, Catalytic

Thursday, February 25,1999Grand Quivira Room

7:30-8:00 Continental Breakfast

Heterogeneous CatalysisNuclear Magnetic Resonance

8:00-8:25 P. Ellis, PNNL, Development of NMR Based Catalysis End-Stations: Applications to Homogeneousand Heterogeneous Catalysis

Metal Oxides and Partial Oxidation

8:25-8:508:50-9:159:15-9:40

9:40-10:05

10:05-10:20

10:20-10:5510:55-11:20

11:20-11:45

11:45-12:10

A. Redondo, LANL, Olefin Epoxidation on Ag SurjacesJ. Nicholas, PNNL, Computational Catalysis at PNNLK. Ott, LANL, Reactivip and Stability of Titanium Silicate Catalysts: TS-1, Ti-MCM-41, and Cpti-Silsesquioxane/MCM-41M. Gutowski, PNNL, Towards Computational Modeling of Heterogeneous Catalysis: Metals andMolecules on MgO

Break

J. Miller, SNL, Oxidative Dehydrogenation of Propane Over Mixed Molybdenum OxidesD. Zerkle, LANL, Mode[ing of Catalytic Partial Oxidation on Pt with Detailed Gas-Phase andSu~ace KineticsM. Paffett, LANL, Fundamental Interactions of Hz, Oz, and H20 at Actinide and Actinide OxideSu@acesT. M. Orlando,I?NNL,Nonthermal Processes on Oxide Suvaces and lnteqlaces

7

. . . ... . ..

12:10-1:30 Lunch (On your own - Buffet in Hotel Restaurant)

Electrocatalysis

1:30-1:55 D. Dubois, NREL, Development of Electroeatalysis for CO1Reduction and Alcohol Oxidation

Automotive Catalysis

1:55-2:20 J. Reynolds, LLNL, Mixed-Metal Oxide Aerogels in NOX Aj?ertreatment2:20-2:45 D. Mullins, ORNL, Opportunities in Catalytic Research Using Sojl X-ray Photoelectron

Spectroscopy>.45.3:10 C. Peden, PNNL, Mechanistic Aspects of Automobile Exhaust Catalysis: Su~ace Science Studies

using Model, Single Crystal Catalysts

3:10 Adjourn General Meeting

3:30-4:30 Continue Business Meeting if necessary

8

Guest S~eakers

Prof. Christopher John Adams, MA(Oxon), D.Phil, FRSCDirector, Institute of Applied Catalysis

Educated at Oxford University, Chris Adamsspent 5 postdoctoral years in Oxford andBerkeley, working on fluorine chemistry of main~woupelements, especially xenon and iodine. In1975 he joined Unilever Research, and hasworked in research to support Unilever’sHousehold Products and Speciality ChemicalsBusinesses, more than half of the time in seniormanagement positions. From 1992 to 1997Chris was Director of Chemicals Research andHead of Measurement Sciences Division,Unilever Research Port Sunlight Laboratorywhere he was responsible for the central Researchprogrammed which supported Unilever’sspecialitychemicals businesses (silicas, catalysts, zeolites,oleochemicals, perfumes and flavorings,polymers, adhesives, and diagnostic test kits), andhad a role in developing overall research strategiesfor these businesses. The position includedresponsibility for the Catalysts and Silicas Section,Unilever’s technical resource in inorganicchemistry and inorganic materials, with 30 staff(12 PhDs).

He is currently seconded by Unilever to setup and run the new virtual Institute of AppliedCatalysis, established by the Technolo=gForesight Programme. This task is to create fromscratch a virtual institute to the entire UKchemicals and pharmaceutical industry whichwill promote the application of catalysis throughindustrially led interdisciplinary research andeducation programmed. iAc is owned andmanaged by its 15 industrial members and 70

a model for Industry Research Associations forthe next century.

Chris has also promoted the importance ofapplied science through publication, teaching asa visiting professor at Belfast and Liverpool, andby giving popular science lectures. b 1994 Chriswas appointed to an Honorary Chair in Chemistryat Queen’s University Belfast, and since 1995 hehas also held an Honorary Chair in Chemistry atLiverpool University. Chris teaches industrialinorganic chemistry, with a special focus on therelationship between the hierarchical structure ofinorganic materials, manufacturing systems, theirapplication properties and the way they areexploited as intellectual property.

As an inorganic chemist, Chris madesia~ificant original contributions to elucidatingand enlarging the chemistries of a wide range ofsystems. A consistent theme has been tounderstand and exploit the relationships betweenstructure, thermodynamics and reactivity, usingadvanced measurement techniques. A notablefeature in his career has been the scientificcontributions made in the course of industrialapplication research; Chris has published some40 papers, patents, books and review articles.

He has contributed to the work ofprofessional societies (RSC, SCI), has served onadvisory bodies for 6 universities, as well as theCIA and several Government committees,including the Technolo=~ Foresight ChemicalsPanel - and is co-author of a new international~~ide to quality in analytical chemistry.

acade-fic members, and is already established as

Wednesday February 24,1999 8:30 Aikl (General Session Speaker)

Applied Catalysis: The UK Solution

The talk describes the aims, organisation, programmed and future of the Institute of Applied Catalysis,an industrially-led organisation created in the UK to promote applied catalysis. This is one of a number ofcurrent initiatives in developed nations to seek collaborative solutions to enhancing industry-universitygovernment collaborations in catalysis R&D.

The development iAc is presented in terms of● the UK Technolo=g Foresight Programme● UK University initiatives in catalysis. Government and other agencies

Strengths and weaknesses of the UK approach will be discussed.

9“

Dr. R. A Periana, Director of ResearchCatalytic

Dr. R. A. Periana joined Catalytic in 1988. He iscurrently Director of Research and co-founder ofCatalytic Advanced Technologies, Inc. a whollyowned subsidiary of Catalytic, Inc. He is alsoproject leader for Catalytica’s mtdti-miilion dollarDirect Methane (and Higher Alkane) Oxidationprograms aimed at developing next-generationtechnology to produce methanol, ethylene glycol andother higher alkane products directly from the parent

alkanes. He is inventor of molecular catalyst systemsthat exhibits the highest one-pass yield (-7f)~0 at>90% selectivity) ever reported for the oxidativeconversion of methane to methanol. Reports ofaspects of this work have been reported in Science,259, 340, 1993 and Science, 280, 340, 1998. Thework has received world wide coverage in journalssuch as Wall Street, New York Times, C&E News,

Chemical Week, Oil and Gas. Dr. Periana is theprogram manager and technical author of a $4 MMco-share research .gant from the NIST sponsoredATP program that was awarded to Catalytic forfurther development of the Direct Methane Oxidationtechnology. Over the last 5 years he has raised over$6MM in research funding. He has co-authored 19patents and 16 journal articles and has been invitedspeaker at the Bloomberg Conference on Energy,Gordon Organometallic Chemistry Conferences,Natural Gas Conversion Symposium, Euro-CatConferences and other international meetings as wellmany major US and International universities. Dr.Periana’s key role at Catalytic is the identificationand development of next generation technologies inthe Energy, Petrochemical, Specialty and FineChemical sectors.

Wednesday, February 24,1999 8:OOPA4 (Dinner Speaker)

Developing the iVext Generation Processes with the Aid of

Molecular Catalysts

The role next-generation, direct, oxidation processes in helping to define the Power and PetrochemicalIndustry of the 21st century will be discussed. As a specific example of a potentially useful direction todeveloping these processes, novel, molecular, CH Activation catalysts will be discussed that allow thedirect, low temperature, oxidative conversion of methane to a methanol equivalent product in 70% one-pass yield. A particularly effective system is based on 20rnM solutions of (bipyrimidine)PtC12 inconcentrated sulfuric acid. Reaction of methane at 500 psig and 2200C with this solution result in 90%conversion of methane to methyl bisulfate in 80% selectivity (-7090 one-pass yield) based on addedmethane. The reaction is proposed to proceed via CH activation of methane by Pt(II) species to generate a

platinum-methyl intermediate that is oxidized to generate the product, methyl bisulfate.

10

\-

Heterogeneous Catalysis

Wednesday February 24,1999

10:00-10:2510:25-10:5010:50-11:15

11:15-11:40

1:15-1:40

1:40-2:052:05-2:30

2:30-2:552:55-3:20

3:35-4:004:00-4:25

4:25-4:504:50-5:15

Novel CatalyticMaterialsK. Carrado, ANL, Preparation and Characterization of Mesoporous Synthetic ClaysY. Wang, PNNL, Mesoporous Silica Suppotied Solid Acid CatalystsT. Gardner, SNL, Synthesis, Characterization, and Testing of Novel Hydrous Metal Oxide-Supported Catalyst MaterialsJ. Darab, PNNL, Nano-Cgwtalline Particulate Catalyst and Catalyst Support Materials GeneratedUsing A Flow-Through Hydrothermal Process

PhotocatalysisS. Elder, PNNL, The Synthesis of New Nanocyrstalline MoXTiI.x02Materials with TailoredPhotophysical PropertiesK. Magrini, NREL, Application of Solar Photocatalytic Oxidation to VOC-Containing AirstreamsD. Blake, NREL, Photocatalytic Cell Killing and Oxidation of Whole Cells in Contact withIlluminated Titanium Dioxide Suq$aces

Novel Processing ConditionsD. Ginosar, INEEL, Alkylation of Aromatics at Supercritical Fluid ConditionsD. Elliott, PNNL, Development of Heterogeneous Catalysis for Use in Aqueous Phase Processing

Metals and SulfidesN. Jackson, SNL, Attrition-related Morphology Changes in Iron Fischer-Tropsch CatalystsJ. RodrigueG BNL, Characterization of Oxide Catalysts using Synchrontron-Based Time-ResolvedX-ray Absorption Spectroscopy (xAS)C. Marshall, ANL, Improved Catalysts for the Removal of Sulphurfrom Heavy HydrocarbonsJ. Hrbek, BNL, Macroscopic and Atomistic View of SuljiurInteractions with Model BimetallicCatalysts

Thursday February 25,1999

Nuclear Magnetic Resonance8:00-8:25 P. Ellis, PNNL, Development of NMR Based Catalysis End-Stations: Applications to Homogeneous

and Heterogeneous Catalysis

Metal Oxides and Partial Oxidation8:25-8:50 A. Redondo, LANL, Olejin Epoxidation on Ag Su@aces8:50-9:15 J. Nicholas, PNNL, Computational Catalysis at PNNL9:15-9:40 K. Ott, LANL, Reactivi~~and Stabili~ of Titanium Silicate Catalysts: TS-1, Ti-MCM-41, and Cpti-

Silsesquioxane/MCM-419:40-10:05 M. Gutowski, PNNL, Towards Computational Modeling of Heterogeneous Catalysis: Metals and

Molecules on MgO10:20-10:55 J. Miller, SNL, Oxidative Dehydrogenation of Propane Over Mixed Molybdenum Oxides10:55-11:20 D. Zerkle,LANL, Modeling of Catalytic Partial Oxidation on Pt with Detailed Gas-Phase and

Su@ace Kinetics11:20-11:45 M. Paffett, LANL, Fundamental Interactions of H2, O> and H20 at Actinide and Actinide Oxide

Surjlaces11:45-12:10 T. M. Orlando, PNNL, Nonthermal Processes on Oxide Su~aces and {nte~aces

Electrocatalysis

1:30-1:55 C.Curtis, NREL,Development of Electrocatalysis for C02 Reduction and Alcohol Oxidation

Automotive Catalysis1:55-2:20 J. Reynolds, LLNL, Mixed-Metal Oxide Aerogels in NOX Ajlertreatment2:20-2:45 D. MuUins, ORNL, Oppo~unities in Catalytic Research Using Sojl X-ray Photoelectron

Spectroscopy2:45-3:10 C. Peden, HVNL, Mechanistic Aspects of Automobile Exhaust Catalysis: Su~ace Science Studies

using Model, Single Crystal Catalysts

11

Novel Catalytic Materials

Preparation and Characterization of Mesoporous Synthetic Clays

Kathleen A. Carrado and Langqiu XuChemistry Division 200, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439

Mesoporous synthetic clays (MSCS) are obtained when polymer-containing silicate gels are hydrothermallycrystallized to form layered magnesium silicate hectorite clays containing polymers that are incorporated in situ. Inthis in situ technique, interlayer intercalation of different polymers over broad molecular weight and concentrationranges is achieved. The polymer loading of synthesized composites is determined by thermal analysis, and the basalspacing changes resulting from different levels of polymer intercalation are monitored by X-ray powder diffraction.In some cases intercalation occurs to such a degree as to delaminate the layers and cause loss of stacking registry.Polyvinylpyrrolidone (PVP) of several average molecular weights ranging from IOKto 1.3M, in loadings varyingfrom 10-20 wt%, were used. The organic polymer template molecules were removed from synthetic polymer-claycomplexes via calcination. Pore radii, surface areas, and pore volumes of the resulting porous inorganic networks(mesoporous synthetic clays) were then measured. A direct correlation between both PVP Mw and polymerloading on the diameter of the average pore was found, which varied from 40 to 100:. Samples have been tested inpreliminary hydrodesulfurization experiments for reactivity and selectivity of dibenzo-thiophene to biphenyl, incollaboration with C. Marshall (ANL).

Acknowledgement:This researchwosperformedunderthe auspicesof the U.S.Dept.of Energy,Officeof BasicEnergySciences,DivisionofChemicalSciences,undercontractno. W31-109-ENG-38.

Mesoporous Silica Supported Solid Acid Catalysts

Yorw Wang, Saemin Choi, Jun Liu, and Charles H.F. PedenPacific Northwest National Laboratory, P.O.Box 999, Richland, WA 99352, USA

Currently, the chemical and petrochemical industries produce a wide range of organic compounds via alkylation andisomerization by homogeneous acid catalysts such as HzSOA,HF, and A1C13.Although these homogeneous catalystsare efficient, their corrosive and toxic nature provides imminent and potential environmental hazards and presentoperational. Solid catalysts with very strong acidity are currently under extensive investigation as environmentallysound alternatives to these homogeneous acids. In our study, a new class of solid acid catalysts was synthesized bygrafting strong acidic functional groups on mesoporous silica namely, supported sulfated zirconia, heteropoly acid andheteropolyacid salt. The effects of sample preparation and support characteristics on the physical and chemicalproperties of synthesized solid acid catalysts were evaluated using different techniques such as TPD, TGA/DSC, TEM,FTIR, NMR, XPS, XRD, and potentiometric titration. Catalytic activity and selectivity of the novel solid acid catalystswere tested using butane isomerization and aromatic alkylation reactions.

12

Synthesis, Characterization, and Testing of Novel Hydrous Metal Oxide-Supported Catalyst Materials

T. J. Gardner, L. I. McLaughlin, and R. S. SandovalNew Materials Theory and Validation Department, Sandia National Laboratories,

P. O. Box 5800, MS 0710, Albuquerque,NM87185

Hydrous metal oxide (HMO) materials are inorganic ion exchangers which have many desirable characteristics forcatalyst support applications, including high cation exchange capacity, anion exchange capability, high surface area,ease of adjustment of acidity and basicity, bulk or thin film preparation, and similar chemistry for preparation ofvarious transition metal oxides (e.g., TiOz, ZrOz, Nbz05, and Taz05). These support materials have been used tofabricate a variety of heterogeneous catalysts for coal liquefaction, hydrotreating, and automotive applications.Following a detailed description of HMO synthesis via sol-gel techniques, catalyst precursor preparation via ionexchange, and catalyst activation, this paper will focus on the characterization of a variety of HMO-supported metal,oxide, or sulfide catalysts. The performance of these novel materials relative to commercial benchmark catalystswill also be discussed in terms of activity testing with both model compounds and realistic feeds. The extension ofbulk catalyst processing techniques to prepare HMO-supported catalyst coatings on engineered substrates will alsobe discussed with respect to catalyst preparation, characterization and performance for these various applications.

Thisworkwas supponedby the UnitedStatesDepartmentof EnergyunderContractDE-AC04-94AL85000.Sarrdiais a multipro=gmlaboratoryopermedby SandiaCorporation,a LockheedMartinCompany.for the UnitedStatesDepartmentof Ener=sj.

Nano-Crystalline Particulate Catalyst and Catalyst Support Materials GeneratedUsing A Flow-Through Hydrothermal Process

John G. Darab,John C. Linehan,and DeanW. MatsonPacific Northwest National Laboratory*, P.O. Box 999, MS K3-59, Richland, WA 99352

A wide range of ultra-fine, nano-crystalline single- and multi-component metal oxide and oxyhydroxide powdersexhibiting surface areas of approximately 50-400 m2/g has been produced using the Rapid Thermal Decompositionof precursors in Solution (RTDS) technology. RTDS, which was developed at the Pacific Northwest NationalLaboratory, is a continuous, flow-through, hydrothermal process capable of producing finely divided nano-crystalline powders at rates of up to 500 -gramsof solid per hour using existing equipment. Control over crystallinephase and, in some cases, particle morphology and aggregation can be tailored by selecting the appropriate feedchemistry and RTDS processing conditions. RTDS has been used to prepare gram to kilogram quantities of nano-crystalline iron oxides, oxyhydroxides and oxyhydroxysulfates, copper-zinc oxide mixtures, titania, and sulfate-promoted zirconia particulate catalysts or catalyst precursors. Additionally, nano-crystalline zirconia and ceria-stabilized zirconia powders generated using RTDS have been successfully processed into stable, high-surface-areazirconia and ceria-stabilized zirconia catalyst support materials. The RTDS processing of these particulate materials,their characterization, and the evaluation of their applicability as catalysts or catalyst supports will be presented anddiscussed.

* PacificNorthwestNationalbboratory is operatedfor the UnitedStatesDepartmentof Ener=gby the BattelleMemorialInstituteundercontractDE-AC06-76RL01830.

13

Photocatalysis

The Synthesis of New Nanocrystalline Mo,Til..OZ MaterialsWith Tailored Photophysical Properties

Scott H. Elder, F. M. Cot, Y. Gao, and Y. SuEnvironmental Molecular Sciences Laboratory and Materials and Chemical Sciences

Pacific Northwest National Laboratory, Richland, WA 99352

The photophysical properties of TiOZ(primarily the anatase form) have been studied extensively over the pastseveral decades, but current forms of TiOz have limitations with respect to their practical use in catalysis and energyconversion utilizing solar photons. We have discovered and characterized several new Kinetically stable solid statematerials based on TiOz that begin to address some of these photophysical property issues. We have accomplishedthis using a novel synthetic route whereby the nucleation of these new metal oxide materials is promoted viasurfactant rnicelle/metal-oxide-cluster reactions. As an example, we have synthesized the series of new compoundsMoXTil.XOZ(x < 0.30) that exhibit a continuous decrease in anatase crystallite size and band gap red-shift withincreasing x. To illustrate, MoO.jOTiO.TOOzhas a band gap of 2.61 ev (the bandgap of Ti@ is 3-2 ev) and averageanatase crystallite size of-45 ~. This places the band gap of nanocrystalline MOO.SO~IO.TOQwell into the visible andmay potentially allow this new material to more efficiently utilize photons from the sun in photoactivated processes.

Application of Solar Photocatalytic Oxidation to VOC-Containing Airstrearns

A. S. Watt, K. A. Matini, L. C. Boyd, E. J. Wolfrum, S. A. Larson, C. Roth, and G. C. Glatzmaier. NationalRenewable Energy Lab, Golden, Co, 80401

Researchers from NREL recently conducted two pilot-scale studies located at McClellan Air Force Base (M%) inSacramento, California and at the Fort Carson U. S. Army Installation in Colorado Springs, Colorado. The objectiveof the tests was to determine the effectiveness of solar-powered photocatalytic oxidation (PCO) treatment units fordestroying emissions of chlorinated organic compounds from an air stipper at ambient temperature and des~oyingpaint solvent emissions from a painting facility with higher temperatures. Our goal for field testing these solar.

driven systems was to gather real-world treatability data and establish that the systems maintained performanceduring the duration of the testing. We will report the results of these field tests and discuss both applications andlimitations of the technology.

14

.- .+.4.

Photocatalytic Cell Killing And Oxidation Of Whole Cells In Contact WithIlluminated Titanium Dioxide Surfaces

Daniel M. Blake, Edward J. Wolfrum, Pin-Ching Maness, Zheng Huang, and William A. JacobyNational Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393

Titanium dioxide surfaces exposed to near UV light exhibit a strong, photocatalytic bactericidal effect. Themechanism of the cell killing effect and the subsequent oxidation of the total cell mass to carbon dioxide is thesubject of this report. It has been assumed that the cell wall and cell membrane of bacteria is the site of initial attackbut clear evidence had not been presented. The aim of the present study is to demonstrate the TiOz-mediated cellmembrane damages and their contribution to cell death. A sensitive approach using a chromogenic @D-galactosidase substrate, o-nitrophenol ~-D-galactosidase (ONPG) as the probe and Escherichia coli K-12 as modelcells has been developed. This approach is used to illustrate damages to both cell membrane and intracellularcomponents caused by TiOz photocatalytic reaction. Treatment of E. coli (10Gcfu/ml) with TiOz (P25, 0.1 %) andUV light (356 nm, 8 W/mz) resulted in an immediate increase of permeability to small molecule such as ONPG andthe leakage of large molecule such as ~-D-galactosidase after 20 min. Further demonstration of the disruption ofmembrane functions is provided by evidence for lipid peroxidation, and decreased respiratory activity. Theoccurrence of lipid peroxidation and the simultaneous losses of both the membrane-dependent respiratory activityand the cell viability depended strictly on the presence of both light and TiOz. Cell killing takes place in the timeframe of minutes. Dead cells are oxidized to carbon dioxide in the time frame of hours. Kinetics of thesephenomena and mass balances on cell content will be presented.

15

Novel Processing Conditions

Alkylation of Aromatics at Supercritical Fluid Conditions

DanielM. Ginosar, Ph.D.Lockheed Martin Idaho Technologies Co. Idaho National Engineering and Environmental Laboratory

The chemical industry produces more than 15 billion pounds per year of alkyl aromatics via the liquid acid catalyzedalkylation of aromatics. Aromatics are combined with olefins over concentrated liquid acid catalysts. Theseconcentrated liquid acids pose serious safety and environmental concerns due to the transport and storage ofconcentrated liquid acids and disposal of acid-hydrocarbon sludges. A solid acid catalyst could replace liquid acidsand eliminate these safety and environmental concerns; however, solid catalysts deactivate rapidly due to thebuildup of coke.Supercritical Fluids (SCFS) have unique volubility and transport properties that make them ideal for extraction inporous media, such as solid acid catalysts. By operating a solid catalyst alkylation process at SCF conditions cokeforming compounds can be extracted from the catalyst surface as they are formed resulting in long catalyst lifetimesand high catalyst activity. An experimental program was undertaken to explore the effect of SCF operation on theheterogeneous catalytic alkylation of toluene. Results are presented on catalytic activity, catalyst deactivation andproduct selectivity at gas, liquid, SCF and near-critical conditions. SCF and near-critical conditions showed clearadvantages for minimizing catalyst deactivation compared to gas phase conditions and clear advantages for productselectivity compared to liquid phase reaction conditions.

Development of Heterogeneous CatalystsFor Use in Aqueous Phase Processing

Douglas C. Elliott, John G. Darab, Scott H. Elder, Yong WangPacific Northwest National Laboratory, P-O. Box 999, MSIN IQ-12, Rlchland, WA 99352

At Pacific Northwest National Laboratory we have been developing catalytic process chemistry for use in anaqueous processing medium. These chemistries range from catalytic reforming to hydrogenation of oxygenates. Inall cases, the common element has been the need to develop catalytic materials particularly designed for use in theaqueous medium. Our need has been for stable catalyst supports and metal/support formulations for use in water attemperatures from 200°C up to 350”C. In these high-pressure, hot-water systems conventional alumina- and silica-based supports are not useful because of their reactivities and solubilities.

We have been evaluating and developing new catalyst supports and metal/support formulations for use in hotaqueous systems. Materials to be discussed in this presentation include titanias, zirconias, and carbons. Newmanufacturing methods including those based on hydrothermal methods will be presented. Applications of thesecatalysts to be discussed in this presentation include organic chemical manufacturing wastewater cleanup viacatalytic gasification of organics in water and production of glycols and other polyols from renewable carbohydratefeedstocks.

16

-.

Metals and Sulfides

Attrition-related Morphology Changes in Iron Fischer-Tropsch Catalysts

Nancv B. Jackson and Lindsey Evans,Sandia National Laboratones, PO Box 5800, MS 0710, Albuquerque, NM 87185

Abhaya Datye, University of New Mexico,Department of Chemical and Nuclear Engineering, Albuquerque, NM 87131

Temperature programmed reduction and transmission electron microscopy was used to study the morphologychanges of an iron Fischer-Tropsch (IW) catalyst during reaction. Although iron IW catalysts are usually introducedto the reactor as oxides, and often reduced to the metal, only carbided iron is active for FT synthesis. Themorphology changes of the iron catalyst have a significant effect on the catalyst integrity with morphologicalchanges often leading to attrition. The effect of promoters such as potassium and copper on catalyst morphology wasexplored. Potassium appeared to minimize the formation of one type of carbide and, at low concentrations, limitedgraphitic carbon formation. At higher potassium levels (3%)graphiticcarbonbegan to re-appear. Copper-promotedcatalystsexposed to higherreactiona temperature(whichis knownto causeattrition)formeddifferentcarbidesthanthose exposed to lower reaction temperatures. The active iron carbide catalyst has a 1-3 nm carbonaceous layer,which can only be found on the carbided iron catalyst (no carbonaceous material is found on iron oxide particlespresent in the same reaction mixture). The carbonaceous material is amorphous, does not require hydrogen to form,and is the starting material for Ff products.

Characterization of Oxide Catalysts using Synchrotron-Based Time-Resolved X-ray Diffraction (XRD) andX-ray Absorption Spectroscopy (XAS)

Jose A. Rodriatez, Sanjay Chaturvedi, Jonathan C. Hanson, and John Z. LareseChemistry Department, Brookhaven National Laboratory

Joaquin L. Brito, Centro de QuimicaVenezuelan Institute of Scientific Research (IVIC)

Investigations at Brookhaven National Laboratory have established the feasibility of conducting sub-minute, time-resolved x-ray diffraction (XRD) experiments under a wide variety of temperature and pressure conditions (-190 C <T <900 C; P <50 atm). This importantadvanceresults fromcombiningthe high intensityof synchrotronsradiationwith new paralleldata-collectiondevices. The instrumentationfor time-resolvedXRDcan be coupledto anapparatus for the measurement of reaction kinetics, and in this way one can monitor simultaneously the activity andstructure of catalysts under relevant reaction conditions. Examples of problems studied to date include the kineticsof phase transformations in mono- and bimetallic oxides, the hydrothermal synthesis and thermal dehydration ofzeolites, the binding of substrates and inhibitors in zeolites, and the sulfidation and reoxidation of oxide catalysts.Results that illustrate the capabilities of time-resolved XRD will be discussed, making emphasis on recent work thatdeals with the properties of cobalt- and nickel-molybdate catalysts. Co and Ni molybdates are importantcomponents of industrial catalysts for the partial oxidation of hydrocarbons and precursors in the synthesis ofhydrodesulfurization catalysts. The molybdates can adopt several structural phases that exhibit different catalyticbehavior. We have examined the properties of these systems using time-resolved XRD, x-ray absorption near edgespectroscopy, temperature programmed reduction and first-principles density-functional calculations.

17

Improved Catalysts for the Removal of Sulfur from Heavy Hydrocarbons

Christopher L. Marshall, Di Wei and James R. BrennerChemical Technology Division, Argonne National Laboratory

9700 South Cass Avenue, Argonne, IL 60439-4837

Because the sulfur content of crude oil is rising as oil quality declines, refiners need more robust, higher-activitycatalysts for hydrodesulfurization (HDS). Past work (at Argonne and elsewhere) in HDS catalysis has concentratedon single aspects, such as activity or selectivity. Our current projects seek to optimize all aspects of the catalyst,including active phase type and synthesis, support porosity, and so on, while also gaining a fundamentalunderstanding of the oil to be processed. It is believed that by studying all aspects of the HDS process we can makethe dramatic leaps in knowledge that are necessary for the processing of large volumes of high-sulfur crude.

Working under a cooperative research and development ageement with UOP (Des Plaines, Illinois), Argonne isfocusing on three areas likely to yield those leaps: processing techniques to reduce particle size, identification of the“bad actors” in the feed and products, and improved catalyst supports.

The following seminar will examine work aimed at understanding all aspects of HDS catalysis and emphasizerecent successes in improving support materials. For example, the pore size of the catalyst is being optimized viatwo different approaches. In the first, mesoporous clays are custom-synthesized with pores that more closely matchthe molecular diameters of the feed molecules as determined via neutron scattering. Catalysts containing poresapproximate1y~50% larger than the feed molecules have been shown to improve catalyst performance whencompared to catalystswithpores that are eithersignificantlylargeror smaller.The focusof future workwill be onoptimizingthesepore:eornetries.

The second approach involves combining the active phase and support in one structure. Cobalt clusters, one ofthe known active phases in HDS catalysis, serve as pillars in a structure of molybdenum sulfide (MoSZ), a materialwith both catalytic and support roles in commercial catalysts. The advantage of this type of catalyst is that the activephase (coGsS) is in intimate contact with the support phase (MoSJ. The support anchors the feed molecules at thesite of the catalysis, optimizing the interaction between the three necessary phases (active phase, support, and feed).The cobalt-pillared MOSZmaterials have activities comparable with those of commercial catalysts, but with betterselectivities for the most desirable products.

This projectis undertalcenin collaborationwith UOPand is fundedby the Departmentof Energy,Officeof FossilEnergy- Tulsa.

Macroscopic and Atomistic View of Sulfur Interactions with Model Bimetallic Catalysts

J. Hrbek], R.Q. Hwangz, J.A. Rodriguez’, T. Jirsak], N.C. Barteltz, M.C. Barteltz,K. Pohlz, J. de la Figueraz and A.K. Schmid z

] Brookhaven National Laboratory, Chemistry Department 555, Upton, NY 11973z Sandia National Laboratories, Surface Chemistry Department, Livermore, CA 94550

In this work we describe the results of a high-resolution photoemission and STM studies of S-interaction withCu, Ag and Au overlayers on Ru(OOI) surface.

The S 2p core level photoemission data indicate that the interaction of S and Au is repulsive. At monolayer Aucoveragethere is no chemicalreactionbetweenthe sulfur and Au and the depositedspeciesare segregated.STMimagesshow that largeAu islandsare dispersedrandomlyinto verysmall3D clustersimmobilizedwithintheoutline of the original dendritic islands.

The interaction of S and the first-layer Ag is very weak with no evidence for chemical reaction. STM studies ofthis system reveal a complex picture of the S-AggdRttinteractions. Sulfur deposited on the first strained layer of Agon Ru interacts by breaking the Ag-Ag and Ag-Ru bonds at the Ag dislocation core. An ordered array of holes filledwith compressed sulfur is created by displaced silver. The hole pattern has a sixfold symmetry and is distorted dueto the hole vibrations at room temperature.

The photoemission data indicate that the chemical reaction of S with the Cu monolayer is also not facile. TheSTM images of the initial stages of sulfur interaction with the first pseudomorphic Cu layer and with the secondstriped layer of Cu show significant structural changes. While a very small amount of sulfur (C 0.001 ML)restructures the first-layer copper, and decorates the dislocation edges and breaks down the striped pattern of thesecond-layer Cu, the chemical reaction starts at much higher S coverages (-0.3 ML).

18

Nuclear Magnetic Resonance

Development of NIMR Based Catalysis End-Stations. Applications to Homogeneous and HeterogeneousCatalysis

Paul D. Ellis and Robert Wind, Pacific Northwest National Laboratory; Environmental Molecular SciencesLaboratory; Battelle Boulevard; P.O. Box 999/ KS-98; Richland, Washington 99352

It is well understood that NMR spectroscopy, in particular in situ methods, can play an important role in thecharacterization of catalytic processes. These investigations complement the more traditional UHV methods.

However, there is not a NMR user facility dedicated to the application and further refinement of this broad array oftechniques. Given the importance of catalysis in the US economy and the role of NMR spectroscopy in thisimportant field. we propose utilizing the unique capabilities and staff of the EMSL to fill this gap.

It is suggested to develop a “catalysis end-station” for ex situ and in situ catalyst characterization on two NMRspectrometers within the Environmental Molecular Sciences Laboratory (EMSL). The new probes for the NMRcatalysis end-stations will include a static-, magic-angle hopping, and magic angle turning flow reactor-probescapable of high temperature and isolalable reactive gas flow over a shallow reactor bed. Further, cryogenic probeswill also be developed and made available for the purpose of structure determination of reactant and productmolecules on the surface of the catalyst. Additionally, a novel method is proposed to investigate homogeneouscatalysis in supercritical fluids by combining medium field (1.4 T) dynamic nuclear polarization and flowingsupercritical fluids to be analyzed at high field, 18.8 T. A critical aspect of this development effort is to obtain thecritical input of potential users before such a program is launched. To illustrate one of the potential applications ofthis methodology to the area of heterogeneous catalysis, a series of low temperature structural and dynamicalexperiments performed on ethylene adsorbed to a supported silver catalyst will be summarized.

19

.

Metal Oxides and Partial Oxidation

O1efin Epoxidation on Ag Surfaces

A. Redondo, J. D. Kress, C. Saravanan, and M. R. SalazarTheoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545

B. E. Wilson

EastmanChemical,Kingsport,TN37662-5150

The epoxidation reactions of ethylene on Ag surfaces with oxygen are examined using two complementary densityfunctional approaches. Results using cluster models and gaussian basis sets are compared with two-dimensionalslab calculations using plane waves. The influence of Cs as an electropositive promoter is also explored.Comparisons are made with experimental thermochemical quantities and kinetic studies of catalytic processes

Computational Catalysis at Pacific Northwest National Laboratory

John B. NicholasEnvironmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory

P.O. Box 999, Richland, WA 99352

The synthetic modification of oxides provides a path to new solid acid catalysts. In collaboration with Prof. JamesHaw (USC), we have found that the Lewis acid S02 reacts with silica and zirconia surfaces to form thermally stable

materialswith strongBr@sted acidity.We willpresenta theoreticalstudy of possibleactivesites on the newcatalysis,includinga comparisonof their acidityto other solid acids.The sensitivityof the theoreticalresults to thecomputational method and cluster size will be discussed. The general concept of activation of Br@nstedacids byLewis acids, and attempts at the determination of a theoretical Lewis acid “activation” scale, will also be presented.The second part of this talk will focus on the theoretical and experimental “titration” of a HZSM-5 active site. We

have experimentally obtained the lH NMR spectra for a series of adsorbates of increasing basicity (range = 180.4-226.8 kcal/mol). All of the adsorption complexes exhibit spectral signatures of strong hydrogen bonds.Theoretically, we determined the optimized geometries of the same series of adsorbates, and thus, energetic and

structure parameters related to the hydrogen bond strength. There is a high (R2 > 0.9) correlation between thetheoretical and experimental measures of hydrogen bond strength. In addition, we obtained the proton affinitythreshold of the adsorbate molecules needed to effect protonation by the zeolite. These studies substantiate earliertheoretical predictions of the protonation threshold for olefins and aromatics in HZSM-5.

20

Reactivity and Stabiiity of Titanium Silicate Catalysts: TS-1, Ti-MCM-41, and Cpti-SilsesquioxanefMCM-41

Kevin C. Ott, Jon Rau, and Francis M. de RegeMS J5 14, Los Alamos National Laboratory, Los Alamos, NM 87545

Substantialliteratureexists in the area of titanosilicate-catalyzedepoxidationof olefinswith hydroperoxideslargelybecauseof the discovery of TS- 1 where Ti has been substituted for Si in the MFI framework. The searchfor large pore analogs of TS- 1 has led to the study of Ti substituted into the ffamework or grafted onto the channelsofMCM-412. Other research has been directed at homogeneous analogs of TS-1, such as CpTLsilsesquioxane, bothin solution as well as immobilized in the mesopores ofMCM-413. Thomas et aL2has reported that the synthesismethod is important in determining the ultimate activity of the catalyst, and has shown that synthetic procedures thatresult in site-isolation of Ti ions give superior catalysts.

In our work, we have examined more closely the relationship between mode of synthesis and Ti loading andcatalytic activity as well as on leaching and catalyst deactivation during cycling of the catalyst using the epoxidationof oletins with t-butylhydroperoxide as a probe reaction. We have examined the grafting of Ti onto MCM-41 viathe reaction of tetraethylorthotitanate and titanocene dichloride with surface silanols. A third synthesis routeinvolving the incorporation of Ti into the zeolite synthesis gel was also studied. These studies have yieldedinteresting and unexpected results regarding the activity as a function of Ti loading, catalyst synthesis route, Tileaching, and catalyst deactivation. We will discuss our preliminary results of similar features for CpTi-silsesquioxane-MCM-4 1. Finally all of these Ti silicate catalysts will be compared with the prototypical Ti-silicatecatalyst, TS- 1.

References:t). B. Nomri,Cxstysis Today 18. 163(1993).3. T. Maschmeyer.F. Rey.G. .%nkar.and J. M.Thomas,Nature378, 159(1995).3). S. Krijnen.H.C.L.Abbenhuis.R.W.J.M.Hanssen.J.H.C.van Hoof,and R.A.van Sanren,Angew.Chem. tnt. Ed. 37,356 (1998).

Towards Computational Modeling of Heterogeneous Catalysis: Metals and Molecules on MgO

Maciei Gutowski, John E. Jaffe, Zijing Lin, James A. Snyder, Anthony C. HessPacific Northwest National Laboratory, Materials Resources, Richland, WA 99352

We describe a computational surface physics and chemistry study using a density functional theory code for systemsperiodic in two or three dimensions. The theoretical approach is formulated for localized Gaussian basis sets ratherthan for plane waves and uses an auxiliary Gaussian basis set to represent the charge density. The analytic “forces”,i.e., derivatives of the energy with respect to displacements of atoms in the unit cell, greatly simplify computationalstudies of physiochemical problems. The code, GAPSS, is implemented on massively parallel computers (IBM 5P,CRAY-T3E). Numerical results are presented for co-adsorption of alkali metal atoms and CO molecules on theMgO surface. This system may be considered as a model supported-metal catalyst. Our results demonstrate a strongcooperativity in the case of co-adsorption. The energy required to de-sorb CO from the surface decreases by 32%due to the presence of the layer of sodium atoms. Similarly, the binding energy of Na’s decreases by 8 % due to thepresence of the co-adsorbed CO molecules. The equilibrium internuclear separation for CO molecules increases byca. 0.005 ~ when adsorbed on the MgONa model catalyst relative to gas phase molecules. We have foundsignificant differences between the LDA and gradient corrected predictions, with LDA leading to larger bindingenergiesandsmallerminimumenergyseparationsbetweeninteractingslabs. The results obtainedwith gradientcorrectedfunctional are moreconsistentthoughthe accuracyof these functional requiresfurtherverifications.

21

Oxidative Dehydrogenation of Propane Over Mixed Molybdenum Oxides

James E. Miller, Allen G. Sault, Nancy B. Jackson, Lindsey Evans, Mary M. GonzalesSandia National Laboratories, Albuquerque NM 87185

Mixed metal oxide systems have been widely studied for oxidative dehydrogenation (ODH) reactions, forexample the ODH of propane to propylene. The metal oxide systems commonly studied consist of numerouspossiblecrystallinephases,and the activeand selectivecatalystcompositionsoften are reportedto containseveralofthesephases,Muchefforthasbeenexpendedtryingto identifythe singleactiveandselectivecrystallinephaseinthese systems, and conflicting conclusions have been drawn. Phase synergism has been reported in several of thesesystems and offered as a possible explanation for apparently conflicting results. This synergism is most commonlyattributed to remote communication of the phases, e.g. through spillover.

We have studied pure and mixed magnesium molybdate phases (e.g. ~-MgMoOd, MgMOzOT,M003) for theoxidative dehydrogenation reaction of propane. All the active/selective catalysts we have tested in this system areinitially composed of at least ~-MgMo04 and one other phase. Yet, pure ~-MgMoOd is inactive and there is nocorrelation between activity and the second phase. All the active catalysts, however, exhibit a unique feature intemperature programmed reduction (TPR) characterization that is not present in the inactive materials and cannot betraced to one of the pure phases. Further, mixtures of inactive phases (i.e. f3-MgMoOdand M003, or ~-MgMo04and MgMoz07) become active over time under reaction conditions just as the TPR feature appears for these mixturesafter heating. XPS studies confirm these observations. After heating mixtures of ~-MgMoO~ and M003, reductionof Mo(VI) to Mo(IV) by propane becomes facile. Hence we conclude that for the Mg-Mo-O system a unique activephase or species for the ODH of propane forms when multiple crystalline phases are present, giving only theappearance of a phase synergy.

This workwassupportedby the UnitedStatesDepartmentof EnergyunderContractDE-AC04-94AL850000..%ndktis a mtdtiprogramLaboratoryoperatedby .%ndktCorporation,a LockheedMartinCompany,for the UnitedStatesDepartmentof Energy.

Modeling of Catalytic Partial Oxidation on Pt withDetailed Gas-Phase and Surface Kinetics

David K. ZerkleLos Alamos National Laboratory, Chemical Science and Technology Division

P.O. Box 1663, Mail Stop J567, Los Alamos, NM 87545Mark D. Allendorf

Sandia National Laboratories, Combustion Research FacilityP.O. Box 969, Mail Stop 9052, Livermore, CA 94551-0969

The conversion of light alkanes to more useful chemicals and fuels, in particular ethane to ethylene, is a veryimportant process in the chemical industry. A two-dimensional modeling effort is in progress which aims toelucidate the fundamental processes governing the catalytic partial oxidation of ethane to ethylene and methane tosynthesis gas on platinum in a short contact time reactor. In conjunction with this effort is a modeling program topredict the catalytic ignition temperatures of methane and ethane on platinum in a stagnation flow. Past developmentof surface kinetic mechanisms for catalytic alkane conversion in short contact time reactors has been limited to one-dimensional numerical treatments such as plug flow reactor models. The kinetic mechanisms proposed and the rateparameters derived from this approach incorporate the systematic error that the plug flow assumption represents.Work currently in progress at Los Alamos and Sandia’s Combustion Research Facility is aimed at developing a morecomplete kinetic mechanism that includes both gas phase and surface reactions. This mechanism will be tested intwo-dimensional flow simulations and compared to the experimental data for partial oxidation. Such a mechanism isexpected to provide broad applicability so that reliable simulations can be achieved for a wider range ofexperimental or industrial configurations. To this end, stagnation flow modeling will also be performed to predictthe ignition temperatures of ethane and methane in the catalytic combustion regime.

22

Fundamental Interactions of H2, 02, and H20 at Actinide and Actinide Oxide Surfaces

Mark Paffett, Les Manner, Jane Lloyd, Roland Schulze, and Luis MoralesCST and NMT Divisions, Los Alamos National Laboratory, Los Alamos, NM 87545

In the areas of actinide waste disposition and storage, and medium to long term retrievable actinide materialsstorage, the issue of water and other small molecule interactions with pure or impure actinide oxide materials andmetal has become a major concern. Small molecule reactions in these types of systems has led to changes inmaterials stoichiometry, containment breaches and dispersal of material resulting from pressurization, corrosion ofthe containment, and the collapse of sealed containers due to the formation of partial vacuum. The exact nature ofthese reactions and the resulting implications for medium to long term storage are not well understood, althoughthere have been a number of studies which have attempted to explain these observations [1-3, and others]. Theinteraction of water with actinide and actinide oxide surfaces constitutes the fundamental technical basis forunderstanding and predicting long term actinide material storage behavior. In this presentation we summarize someof our studies that pertain to these efforts with particular emphasis on gas generation andlor consumption eventsrelevant to actinide materials storage. These studies include fundamental surface studies of actinide and actinideoxide materials with water vapor using a wide variety of physical chemical and surface specific techniques. Inaddition, the catalytic back reaction of Hz and Oz to form HZO at relevant pressures has also been followed in aneffort to ascertain the bounds of experimentally observed gas generation mechanisms that have been inferred fromother works.

1. Reactionsof Plutoniumand UraniumwithWater Kineticsand PotentialHazards,J. Hasctrke,LA-13069-MS,December1995.2. Characterizationof the Plutonium-WaterReactionII: Formationof a BinaryOxideContainingPu(tV)J.L. Stakebake,D.T.brson, andJ.Haschke,J. Alloysand Compounds,202, 1993,251. PlutoniumDioxideStorage:Conditionsfor Preparationand Handling.J.M. Haschke,andT.E. Ricketts,LA-12999-MS,1995.

Nonthermal Processes on Oxide Surfaces and Interfaces

T. M. Orlando,N. G. Petrik, A. B. Alexandrov,andW. C. SimpsonW. R. Wiley, Environmental Molecular Sciences Laboratory,

Pacific Northwest National Laboratorys, P.O. Box 999, MJS KS-88, Richland WA 99352

We are currently conducting a set of controlled experiments to investigate the role of low-energy electronicexcitations and defects on chemical processes on oxide surfaces. Our primary approach is to utilize monochromaticlow-energy electron beams, ultraviolet photon sources, and high energy particles to produce electronic excitationswhich create surface defects or lead to adsorbate dissociation. We also probe carrier recombination and bulk defectstates using laser-stimulated luminescence (LSL). Thus far we have studied i.)photon- and electron-stimulatedresorption (PSD and ESD) of cations from yttria-stabilized ZrOz(lOO) and undoped amorphous Zro? ‘]],ii.)radiation-induced dekmadationof water at several oxide interfaces ‘z]and iii.)LSL of yttria-stabilized ZrOz(100) ’31.The ESD and PSD studies demonstrate the ability to selectively create defect sites and reduced metal sites forcontrolled surface chemistry studies. Threshold energies and photoemission measurements indicate that damageoccurs via a multielectron Auger-decay process. The data from radiation bombardment of oxide particles/waterinterfaces imply efficient irradiation-induced production of molecular hydrogen relative to gas-phase or condensed-phase water radiolysis. This “enhancement” seems to occur for particles with band-gaps between 4.8 and 6.4 eV(i-e. Zro?, Er@J, and others)- Since tttisenhancementonly occurs for certain oxides within the band-gap range of4.8 - 6.4 eV, we speculate that the adsorption geometry of the first water bilayer is important and that thedissociation involves exciton coupling to an adsorbate-substrate complex. Finally, the various activation energies,decay kinetics, and excitationlemission energies observed in the LSL correspond to several emission centers whichcan be associated with anion vacancies. We assign these to intrinsic F-centers and extrinsic F-centers and interpretthe LSL in terms of recombination of mobile holes with trapped electrons.

References:[1] W. C. Simpson.W. K. Wang, J. A. Ymmoff and T. M. Orlando,“Photon-and Electron-stimulatedResorption of 0+ fromZ%conia”’,Su@Sci. in press. [2]N.G. Perrik,A. Alexrmdrov.A. Hall, and T. M. Orlando,“Radiolysisof Water at Oxide Interfaces”,J. Phy.Cherrr-B, in prep.[3]N. G. Petrik, D. P. Taylor turdT. M. Orlando.“Laser-StimulatedLuminescenceof Yttria-StabilizedCubicZirconiaCrys[als”,J. Appl.Phys.submitted.

The PacificNorthwestNationalLaboratoryis operatedfor the US Dept.of Energyby BatteUeMemoriattswituteunderContractNo. DE-AC06-76RL0 1830.

23

Electrocatalysis

Development of Electrocatalysts for CO? Reduction and Alcohol Oxidation

Calvin J. Curtis and Daniel L. DuBoisNational Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393

Electrocatalysis will play an important role in future fuel production and utilization processes. Direct oxidation ofalcohols could lead to the development of fuel cells that can operate on liquid fuels without the need for onboardreforming, and electrochemical reduction of COZ to alcohols using solar-generated electricity would provide anattractive route for storing solar energy. Our research on electrocatalytic reduction of CO? has led to thedevelopment of catalysts that efficiently reduce CO? to CO with high selectivity (current efficiencies greater than90%). These catalysts operate at potentials 0.5 volts more positive than other known CO? reduction catalysts and atmuch higher rates than other known catalysts. Some of the important mechanistic details of these catalysts will bepresented. Initial results demonstrating the potential use of rapid throughput methods for developing alcoholoxidation and CO? reduction catalysts will also be discussed. This research relies on the development of rapidsynthetic techniques, and on multichannel potentiostats for rapid screening. The use of a multichannel potentiostatallows for rapid quantitative measures of current and potential which are very useful in the rapid assessment ofcatalyst performance.

24

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Automotive Catalysis

Mixed-Metal Oxide Aerogels in NOX Aftertreatment

John G. RevnoldsUniversity of California, Lawrence Llvermore National Laboratory, Llvermore, CA 9455 I

Work at Lawrence Livermore National Laboratory has focused on mixed-metal oxides formed in various methodssuch as aerogels and ceramic membranes. In the aerogel work, noble catalysts have been prepared for the use ofNOX reduction in lean-burn internal combustion engines, such as auto and small diesel. These catalysts have beenprepared as mixed metal combinations that contain, in part, noble metals from sol-gel techniques. The solidsproduced are oxidized, aged, and then slurried to forma wash coat to cover catalytic converter forms. Some catalyticmaterials have shown 80% NO removal using C3 hydrocarbons under laboratory testing.

Workperformedunderthe auspicesof the U. S. Departmentof Energyby the LawrenceLivermoreNationalLaboratoryundercontractnumberW-7405-ENG-48.

Opportunities in Catalytic Research UsingSoft X-ray Photoelectron Spectroscopy

David R. Mullins and Steven H. OverburyOak Ridge National Laboratory

X-ray photoelectron spectroscopy has been a work horse technique in catalytic research for studying theoxidation state of catalytic materials and for identifying surface species during reaction processes. The techniquehas been hampered, however, by generally low sensitivity which has limited the ability to study low concentrationsof active metals and adsorbed species. The sensitivity and resoh.ttion can be dramatically enhanced by using soft x-ray excitation from a synchrotronslight source.

We have been studying model reactions on cerium oxide, an important component in automotive exhaustcatalysts. Soft x-ray photoelectron spectroscopy (SXPS) is used to analyze the oxidation state of the substrate, thesurface species that result from exposure to gases such as NO, Oz, HZO, CO and SOZ, and the influence of activemetals such as Pt and Rh that are adsorbed in sub-monolayer amounts on the substrate. A typical spectrum for anyof the components of interest can be recorded in - 1 minute.

The following examples will be discussed. NO adsorption depends on the oxidation state of the ceria andnumerous N containing species are identified. S0? interacts strongly with both fully oxidized and partially reducedsubstrates. By adjusting the khtetic energy of the emitted photoelectron, and thus the electron escape depth, adsorbedOz and HZOproduce O 1s signals that are nearly as intense as the signal from the substrate. The reactivity of CO andNO on evaporated Rh particles is strongly modified by the oxidation state of the oxide substrate.

25

Mechanistic Aspects of Automobile Exhaust Catalysis:Surface Science Studies using Model, Single Crystal Catalysts.”

Charles H.F. Peden, G.S. Herman, Environmental Molecular Sciences Laboratory,

Pacific Northwest National Laboratory*~ Richland, Washington

David N. Belton, Physical Chemistry Department,General Motors Research Laboratory, Warren, Michigan

Automotive emissions of unburned hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOX) are

very effectively controlled in US passenger cars by a heavy reliance on after-treatment of the engine exhaust usingcatalytic converters. The catalytically active component of the exhaust converters is a mixture of platinum (Pt) andrhodium (Rh) metals. Both Pt and Rh are very effective at oxidizing CO to C02, but it is generally believed that Pt

is superior for HC oxidation with Rh being best for NO reduction. In the very near future, new foreign and domesticemission regulations take effect that will significantly increase the demand for catalysts containing these expensive,precious metals. Given these strong pressures on noble metal supply, it is imperative that Rh and Pt are utilized aseffectively as possible for the control of automotive emissions. We have focused on obtaining a more detailedunderstanding of the reactivity of these vital catalyst components with a continuing program to define andunderstand the reaction kinetics over well defined single crystal catalysts under conditions of temperature andpressure comparable to those encountered in automotive exhaust. By studying such well defined model catalysts weare able to isolate the activity of the noble metal component of the catalyst free from complicating factors such asmetal particle size and catalyst support effects. In this presentation, we describe recent results on the reduction ofNO by CO over Rh(l 11), Rh(100) and Rh( 110) single crystal catalysts. In contrast to CO oxidation, this latterreaction displays very interesting sensitivity to the geometric structure of the catalyst surface.

PacificNorthwestNationalt-aborato~ is a mukiprogmrnnationcdlaboratoryoperatedfor the U.S.Depmment of Energyby BmtelleMemorirdInstituteundercontractnumberDE-AC06-76RL01830.

26

(-.<J

Homogeneous CatalysisWednesday February 24,1999

10:00-10:25

10:25-10:50

10:50-11:15

11:15-11:40

1:15-1:40

1:40”205,2:05-2:30

2:30-2552:55-3:20

3:20-3:35

3:35-4:00

4:00-4:254:25-4:504:50-5:15

H-Transfer and Alkane Functionalization

R. M. Bullock, BNL, Hydride Transfer and Hydrogen Atom Transfer Reactions of Transition MetalHydrides - Kinetic and Mechanistic StudiesR. Martin, LANL, Density Functional Theory Studies of C-H Activation in Cationic 0s(11) andPt(II) ComplexesR. Fish, LBNL, Flourous Biphasic Catalysis: A New Paradigm for the Separation of HomogeneousCatalysts from Their Reaction Substrates and Products, as Demonstrated in Alkane and AlkeneFunctionalization ChemistryD. Camaioni, PNNL, Radical Pathways for Selective Oxidation of A1.kanesin Trifluoroacetic Acid

Biocatalysis

J. Kerr, LBNL, Biomimetic Catalysis of Enzyme Co-factor Regeneration with [Cp*Rh(bipy)H]+ andNAD+Models: Mechanistic Aspects, Deactivation, Reaction Rates, and Economic Factors

M, Lin,BNL,Recent Advances in Bioeatalysis of Fossil Fuels

M. E. Himmel, NREL,Protein Engineering for Bioethanol Production

Oxidation and Photocatalysis

A. Bakac, Ames, Catalytic Oxidation Accelerated By a Built-in Chain CycleE. Fujita, BNL, Photochemical Water and Carbon Dioxide Reduction with Metal Complexes

Break

Novel Media, Methods, and Catalyzed Reactions

W. Tumas, LANL, Catalysis and Chemical Synthesis In Dense Phase Fluids: Towards SolventReplacement and Enhanced SelectivityR. Klingler, ANL, High-Pressure NMR Studies of Supercritical HydroformylationsD. Maluzjan, BNL, Homogeneously Catalyzed Selective Synthesis of Methanolfiom Synthesis GasR. T. Baker, LANL, Metal-Catalyzed Deo.qoligo-merization of Carbonyl Compounds usingDiboron Reagents

‘3

27

H-Transfer and Alkane Functionalization

Hydride Transfer and Hydrogen Atom Transfer Reactions of Transition Metal Hydrides - Kinetic andMechanistic Studies

R. Morris Bullock, Tan-Yun Cheng-,Faisal A. Shafiq,Diane E. Cabelli, David J. Szalda, and Carol creutz

Chemistry Department, Brookhaven National LaboratoryUpton. New York 11973-5000, e-mail: Bullock @bnl.gov

Kinetic and mechanistic studies of transition metal hydride complexes are desiegnedto elucidate the factors thatdetermine the rates and mechanisms of M-H bond cleavage reactions that are central to the role of metal hydrides in

homogeneous catalysis. Ionichydrogenationsofalkenes,ketones,andaldehydesproceedthroughinitialprotonationof the organic substrate by a strong acid such as CF3S03H. A transition metal hydride serves as an H- donor in theproduct-forming step. The kinetic hydricity of a series of metal hydrides was determined using stopped-flowmethods. Hydride transfer from neutral transition metal hydrides to Ph3C’BFd-gives M-FBF3 and Ph3CH. Second-order rate constants span a range of over 106. Electronic and steric effects of ligands, effect of metal, activationparameters, and kinetic isotope effects were determined. An inverse kinetic isotope effect (kwH/ km= 0.47) wasfound for (CsHdCOzMe)(CO)3W(H/D).

Complexes with weakly coordinating ligands are important in many homogeneous catalytic reactions. Hydridetransfer from Cp(CO)~(PPhq)MoH to PhJC’13Ar’~[Ar’=3,5-bis(trifluoromethyl)phenyl] save[Cp(CO)z(PPh~)Mo]’BAr’;. A crystal structure of this complex carried out at the National Synchrotrons LightSource showed that one C=C bond of one Ph ring is very weakly coordinated to the Mo.

The water-soluble metal hydride (CjHdCOzH)(CO)qWH is dimeric in the solid state due to hydrogen bonding ofthe COZH groups, as shown by x-ray diffraction. The PK. (HzO) of W-H was dete~ined to be 5-8. One-electronreductions of metal hydrides are studied by pulse radiolysis, along with complementary studies using ‘Co radiation.The mechanism involves W-H bond cleavage to produce metal-centered radicals that subsequently dimerize. Pulseradiolysis was used for the determination of rate constants for hydrogen atom transfer from water-soluble tungstenhydrides.

This researchwascarriedoutat BrookhavenNationalLaboratoryundercontractDE-ACO2-98CH1O886withsheU.S.Departmentof Energyandwassupportedby its Divisionof ChemicalSciences,Officeof BasicEnergySciences.

Density Functional Theory Studies of C-H Activation in

Cationic OS(II) and Pt(II) Complexes

Richard L. Martin and P. Jeffrey HayTheoretical Division, MS B268, Los Alamos National Laboratory

Los Alamos, NM 87545

The potential energy surfaces for the reductive elimination of methane from the OS(IV) methyl hydride complexCp*Os(dmpm)(CH3 )(H)+, where dmpm is bis(dimethylphosphino)- methane, and from the Pt(IV) complexes(en)Pt(CH3)(H)(CH3)+ and (en)Pt(CH3)(H)(Cl)+, where en is ethylenediammine, have been studied with hybriddensity functional theory. Both complexes show bound h2(C,H) intermediates in the exit channel. In the 0s case, amechanism for the exchange of hydrogens in the methyl and hydride positions will be discussed and the kineticparameters compared with the NMR results of Gross and Girolami.

28

F1uorous Biphasic Catalysis: A New Paradigm for the Separation of Homogeneous Catalysts from TheirReaction Substrates and Products, as Demonstrated in Alkane and Alkene Functionalization Chemistry

Jean-Marc Vincent,a Alain Rabion,b Vittal K. Yachandra,a and Richard H. Flsha

‘Lawrence Berkeley National bborato~, UniversiV of California, Berkeley, CA 94720

bGroupement de recherche de Lacq, BP 34, 64170 Artix, France

Fluorous biphasic catalysis (FBC) is a new concept for homogeneous catalysis, where the fluorocarbon solublecatalyst and the substrates/products reside in separate phases. We present the synthesis of a novel fluoroponytailed]igand, tris-N-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,1l-heptadecafluoroundecyl}-l,4,7-triazacyclononane(RfTACN)

2+that is soluble in perfluoroalkanes, and new, monomeric Mn and Coz+fluoroponytailed carboxylate synthons,[Mn(0,C(CHz)zC8F17)zland [CO(OZC(CHZ)ZC8F17)ZI.The initial results on the functionalization (oxidation) of

alkanes/alkenes, using in situ generated, fluorous phase soluble RfMnz+-RfTACN and RfCoz+-RfTACN complexes

(Rf = C8FIT)as the precatalysts, in the presence of t-butyl hydroperoxide (t-BuOOH) and Oz gas as oxidants,

demonstrated that alcohols, aldehydes and ketones could be produced catalytically and that the oxidation productsand fluorous phase soluble precatalysts were indeed in separate phases. The mechanism of oxidation was found to

occur via the Haber-Weiss process, where t-BuOOH was decomposed to t-BuO. radicals, which initiated carbonradical formation, O, trapping to form intermediate alkyl and alkenyl hydroperoxides, the precursors to the above-

7mentioned products.’ A discussion of other mechanistic aspects will also be presented.] J.-M.Vincent.A. Rabion,V. K.Yachandra,R. H. Fish,Ange)v. Chem. Inf. Ed. En,#. 1997.36,2346. These FBC studieswerefundedbyElfAquiminetncand DOE.

Radical Pathways for Selective Oxidation Of Alkanes in Trifluoroacetic Acid

Donald M. Camaioni, Michael A. Lilga, J. Tim Bays, John C. Linehan, and Jerome C. Birnbaum,Pacific Northwest National Laboratory, Richland, WA, 99352

We have shown that the Cu(I)/Cu(II)-Oz-trifluoroacetic acid system oxidizes alkanes to alkyl trifluoroacetate esters.Recent work at the Laboratory has been directed toward gaining insight to the reaction mechanism. By analogy toFenton’s chemistry, reaction of CU(I) with Oz may generate an oxy radical that oxidizes the alkane to an alkylradical. Subsequent oxidation by CU(II) would yield the observed products. Alternative y, the alkanes might reactvia a metal-ion mediated mechanism analogous to Group VIII Noble metals, Hg(II), and T1(I). A third possibility isthat the system essentially generates triftuoroperacetic acid, which is known to oxidize normal and cyclic alkanes toalkyl trifluoroacetates. Both metal-mediated and trifluoroperacetic acid oxidations of alkanes are generallycharacterized as non-radical electrophilic processes in which the electron deficient metal ion, or oxygen intrifluoroperacetic acid, displaces ~ from the alkane. Recent product studies and radical scavenging experimentsperformed on cyclohexane oxidations in Cu(I)/Cu(II)-Oz-trifluoroacetic acid and trifluoroperacetic acid systemsshow that free radicals are key intermediates. Oxidations with added quinoxaline, an efficient alkyl radicalscavenger, produced high yields of cyclohexylquinoxaline in both systems. The presence of CU(II) in theCu(I)/Cu(II)-Oz system caused cyclohexyl radicals to be oxidized initially to cyclohexene that then converted toester. Addition of CU(II) to the trifluoroperacetic system produced trans- 1,2-diester that resulted from the knowrapid epoxidation of cyclohexene by trifluoroperacetic acid. Also, COZand CHF3, signature products for homolyticreaction of trifluoroperacetic acid, were both observed. The results show that selective oxidation of simple alkanesmay be achieved by free radical pathways.

29

Biocatalysis

Biomimetic Catalysis of Enzyme Co-factor Regeneration with [Cp*Rh(bipy)H]+ andNAD+ Models: Mechanistic Aspects, Deactivation, Reaction Rates, and Economic Factors.

H. Christine Lo, Richard H. Fish, Olivier Buriez and John B. KerrLawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720

Interest in processes for regeneration of the co-enzyme, 1,4-NADH, from NAD+ has continued to be activelypursued in the biocatalysis field, where enzymatic reduction reactions are important for chiral, organic compoundsynthesis. We are investigating the reactions of an organorhodium hydride formed in situ with several NAD+

modelsinordertoascertainthesourceofthehighlyregioselectiveformationof theenzymaticallyactive1,4-NADHderivatives. The precatalyst was a (h5-pentamethylcyclopentadienyl)rhodium complex, [CP*Rh(biPy)(H~O)l(OtO~,(bipy = bipyridine). Model NAD+ compounds have helped elucidate the roles of both the amide and sugarfunctional. groups of NAD+ itself in the control of the regioselectivity, rates of reaction, and side reactions that maydeactivate the catalyst. The most probable mechanism found to account for the high regioselectivity involves thecoordination of an intermediate organorhodium hydride, [Cp*Rh(bipy)H]+, with the amide functionality of theNAD+ model, followed by hydride transfer from the Rh to the 4-position of the nicotinamide. The organorhodiumhydride catalyst is formed in situ by chemical (sodium formate), photochemical, and electrochemical means, whichrepresent methods of energy delivery. Moreover, electrochemical measurements in mixed water/organic solventshave shown the need to understand both the redox and acid-base chemistry, prior to immobilization of theprecatalyst in a membrane for separation purposes. The implications of these observations for the design andeconomic application of biomimetic membranes will be discussed.

We acknowledgeDOEfundingfromthe AdvancedEnergyProjectsandTechnologyResearchDivision,Officeof ComputationalandTechnologyResearchunderContractNo. DEAC03-76SFOO098.

.

Recent Advances in Biocatalysis of Fossil Fuels

Mow S. Lin and Eugene T. PremuzicBrookhavenNationalLaboratory,Energy,Science,and TechnologyDivision

Departmentof AppliedScience,BrookhavenNationalLaboratory,Upton,NewYork 11973-5000

Biocatalysis usually refers to the use of microorganisms in the form of whole cells and/or isolated enzymes. Studiesat Brookhaven National Laboratory (BNL) have shown that viable biomass can catalyze solubilization of toxicmetals from different selected geochemical residues, and further, certain thermophilic microorganisms can beutilized in the bioconversion of selected fossil fuels. In the biocatalytic conversion of oils, biodesulfurization,biodenitrogenation and biodemetalization reactions occurs concurrently with redistribution of hydrocarbon fractions.Experimental data indicate that biocatalytic processing is promising and is applicable in the treatment of oils andlow-grade coals. Some of this data will be discussed in the present paper.

30

Protein Engineering for Bioethanol Production

M.E. Himmel, W.S. Adney, S.R. Decker, T.B. Vinzant, S.E. Lantz, S.R. Thomas, and J.O. Baker, BiotechnologyCenter for Fuels and Chemicals,

National Renewable Energy Laboratory, Golden, CO 80401.

Ultra low-cost, saccharifyirg cellulases are required to enable the new bioethanol industry and most would agreethat the development of enzymes with higher specific activities would partially address this objective.Acidothermus celluloly[icus EI is a thermal tolerant endoglucanase isolated from a hot spring bacterium thatdemonstrates very high synergism with fungal cellobiohydrolases. The current strategy to improve the EI catalyticdomain (cd) by PCR mutation was based on a recent 1.8 Angstrom crystallographic structure (Sakon et al. 1996Biochemistry 35, 10648- 10660). Modifications to the enzyme that may be expected to improve its action onbiomass were targeted. PCR mutation was used to generatefamiliesof mutant EI codingsequencesand the aminoacid substitutions were verified at the DNA level. Each active mutant enzyme was purified to homogeneity from 10-L cultures of transformed E. coli using a rapid, three-step column chromatographic method. The purified rEIendoglucanases were subjected to kinetic analyses, including a new diafiltration assay that compares the action ofcelhtlases directly on pretreated biomass under conditions that mimic simultaneous saccharification andfermentation (SSF). Several rEI enzymes demonstrated improved performance on biomass; however, the EIY245Gmutant was especially important, because it provided 12% greater final saccharification of substrate than the wild-type enzyme.

31

_

Oxidation and Photocatalysis

Catalytic Oxidation Accelerated By A Built-In Chain Cycle

Andreia BakacAmes Laboratory, Iowa State University, Ames, IA 50011

In the absence,;f a catalyst, no reaction takes place between tert-butyl hydroperoxide and a macrocyclic rhodium

hydride LRhH- (L = cyclam) in acidic aqueous solutions. The addition of iron(II) ions, even at submicromolarlevels, causes a rapid and quantitative form~aon of methane, acetone and rhodium(III).

(CH3)~COOH+LRhH2+ ~ LRhOH- + CH, + (CH~)zCO

This reaction is several thousand times faster than the typical Fez+-catalyzed oxidations of various substrate:+by

hydroperoxides. The introduction of an additional loop - a chain reaction featuring methyl radicals and LRh- aschain-canying intermediates - into the catalytic process is responsible for the large rate acceleration. Detailedkinetic and mechanistic studies have been carried out. The concept developed here - the power of catalysiscombined with the amplification provided by a chain mechanism - may be put to use to improve rates of othercatalytic reactions.

Photochesnical Water and Carbon Dioxide Reduction With Metal Complexes

Etsuko Fuiita, Bruce S. Brunschwig, Carol Creutz, and Norman SutinChemistry Department, Brookhaven National Laboratory, Upton, NY 11973-5000

OurDOE program addresses three areas fundamental to the efficient capture and storage of light energy:(1) excited-state formation, chemistry, and photophysics; (2) energy transduction by electron-transfer reactions; and (3) energystorage through chemical transformations. We focus the long-term storage of solar energy in this presentation. Thephoto-induced splitting of water into dihydrogen and oxygen and reduction of carbon dioxide to methanol or carbonmonoxide are of considerable interest as processes for photoconverting abundant materials to useful fuels. However,this poses many scientific challenges. Because of the stability of water and carbon dioxide, energy is needed todrive the desired transformations; similarly, its inertness necessitates the use of catalysts. Our research addressesthese formidable problems through the use of transition metal complexes, which can absorb a significant part of thesolar spectrum, have long-lived excited states, and can promote the activation of small molecules. Thephotochemical system typically contains a photosensitizer such as Ru(bpy)3z+,a catalyst such as Rh(bpy)jz+ or acobalt macrocycle, and an electron donor such as triethanolamine or triethylamine. Despite the intense interest andthe need of effective catalysts, the kinetics and mechanism of the photoreactions remain unclear in many systems.Here we present the results of our studies on the kinetics and mechanisms of photochemical water and carbondioxide activation including the characterization of intermediates, using a variety of techniques including UV-vis,NMR, and ~-IR spectroscopy, flash photolysis, pulse radiolysis, X-ray structure determinations, XANES andEXAFS.

This researchwascarriedoutat BrookhavenNationalLaboratoryundercontractDE-AC02-98CHI0884with the U.S.Departmentof Energyandsupportedby its Dtvisionof ChemicalSciences,Officeof BasicEnergySciences.

Novel Media, Methods, andCatalyzedReactions

Catalysis and Chemical Synthesis In Dense Phase Fluids: Towards Solvent Replacement And EnhancedSelectivity

William Tumas, Geoffrey Brown, Charles Carter, Gunilla B. Jacobson, Nathan JosephsonLos Alamos National Laboratory,CST-18, Los Alamos, NM, 87545

We will report on results from an exploratory program at Los Alamos aimed at investigating the use of supercriticalfluids as reaction media in an effort to develop new, environmentally-friendly methods for chemical synthesis andprocessing. This approach offers the possibility of opening up substantially different chemical pathways, increasingselectivity at higher reaction rates, facilitating downstream separations and mitigating the need for hazardoussolvents. We have found that supercritical fluids, particularly COZ, are effective solvents for a wide range ofcatalytic transformations including asymmetric catalytic hydrogenation and hydrogen transfer reduction; selectivecatalytic oxidation of olefins using a number of transition metal catalysts; carbon-carbon bond forming reactionsincluding palladium catalyzed coupling reactions (e.g. Heck and Stille coupling) as well as Lewis acid catalyzedalkylations and acylations; and several processes that utilize carbon dioxide as both a reagent and solvent. We willdiscuss product distributions, selectivity, kinetics, temperature/pressure effects, and mechanistic studies as well ascomparisons with conventional organic solvents. An overview of the Los Alamos Catalysis Initiative will also bepresented.

High-pressure NMR Studies of Supercritical Hydroformylations

RobertJ. Klimzler,JeromeW. Rathke,and Mike Chen,ChemicalTechnologyDivision,ArgonneNationalLaboratory, 9700 South Cass Avenue, Building 205, Argonne, IL 60439-4837

Supercritical fluids are potentially ideal media for conducting catalytic reactions that involve gaseous reactantsincluding Hz, CO, and COZ.The presence of a single homogeneous reaction phase eliminates the gas-liquid mixingproblem of alternative two-phase systems which can limit process rates and adversely affect product selectivities.Our research employs a high-pressure NMR probe with a high-sensitivity toroid detector to provide in situspectroscopic analysis of catalytic reaction intermediates. This experimental approach is well suited to investigatereaction mechanisms in supercritical fluid media. Comparisons between the standard oxo and the phosphinemodified or Shell process will be made. Thus, in situ studies on the cobalt carbonyl catalyzed hydroformylationreaction in supercritical carbon dioxide have demonstrated improved product selectivity for the desired linearaldehyde. In addition, the in situ NMR results definitively establish that $CO(CO)4 radical is present atmechanistically significant concentration levels under standard oxo reaction conditions. This highly reactive odd-electron organometallic complex promotes facile hydrogen atom transfer reactions. The activation parameters forhydrogen atom transfer between cobalt and manganese metal centers have been measured. In contrast, a morecomplex manifold of reactions appears to be operational in the phosphine modified system which involvesheterolytic cleavage of the Co-Co bond. Additional parameters measured for the oxo process in supercriticalQinclude (1) the steady-state concentrations of the catalytic intermediates, (2) the thermodynamics and forward andreverse rate constants for the hydrogenation of co~(co)s, and, (3) the net rate and product selectivity for the overallhydroformylation reaction.

33

Homogeneously Catalyzed Selective Synthesis of Methanol from Synthesis Gas

Devinder MahaianEnergy Science and Technology Division, Department of Applied Science,

Brookhaven National Laboratory, Upton, New York 11973

Homogeneous catalysis is normally associated with high productivity and high selectivity under mildconditions. But only a few processes based on “Single Site” catalysts are commercial. For an economical transportof large reserves of remote and associated natural gas, methanol is identified as an energy carrier and an atom-economical synthesis of methanol from natural gas-derived synthesis gas is the subject of ongoing research atBrookhaven National Laboratory (BNL). To affect this catalytic transformation, a series of highly active nickelcomplexes of the type Ni(CO)XLY(L: basic iigand) have been designed, With these liquid soluble catalysts,

homogeneous hydrogenation of COto methanolhas beenachievedwithper pass gasconversionexceeding90%.These catalystsoperate at a thermodynamicallyfavorablelow temperature(T <150”C)to attain >95% selectivitytomethanol at a low operatingpressures(P< 5MPa). Though the mechanistic details of this novel catalytic route arenot fully established, the commercial potential of this approach is being evaluated in collaboration with industry.Under a BNL/Amoco CRADA, a state-of-the -art bench-scale mini pilot unit, designed and built at Amoco toexclusively evaluate homogeneous catalytic systems, was transferred to BNL and is now on-line. The discussionwill focus on: 1) present status of this novel methanol synthesis technology and its impact on process economics,and 2) implication of this concept in defining “Methanol Economy”. The aim of the BNL effort is to designcatalysts of related chemistry for synthesis of specific energy liquids from synthesis gas that can be economicallyproduced in integated small and product flexible units.

Metal-Catalyzed Deoxyoligomenzation of Carbonyl CompoundsUsing Diboron Reagents

R. Tom Baker and Thomas M. CameronChemical Science and Technology Division, Los Alamos National Laboratory,MSJ514

Los Alamos, New Mexico 87545Richard D. Broene, Department of Chemistry, Bowdoin College, Brunswick, Maine 04011

James M. Boncella,Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611-7200

Boronic acids [RB(OH)Z] are fascinating molecules with a variety of applications ranging from chemical sensors toenzyme inhibitors. We are using metal-catalyzedaddition of diboron compounds to unsaturated, heteroatom-containing organics to prepare functionalizedboronic acids. Studies of ketones and aldehydes with enolizablehydrogens led to an investigation of metal-catalyzed hydroboration of boron enolates. These results will becontrasted with those obtained for aldimines and ketimines (Chem. Commun. 1998, 2395).

34

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.)

‘-.,’

Poster Session AbstractsWednesday February 24,1999 “

#

1 Theoretical Studies of Catalysis at T1 Sites in Zeolites P. Jeffrey Hay, LANL -

z I StructuralAspectsOfTitaniumSitesInTitanosilicates I C. A. Hijar,LANL

3 KineticsOf Hzsm-5DealuminationIn Steam Andrea Labouriau, LANL

4 Probing The Structure Of Metal-Substituted Molecular Sieves By Solid-State Kevin C. Ott, LANLNmr

5 Probing Zeolite Internal Structures Using Very Low Temperature 129xe Nmr Tanja Pietrass5, NMI

6 Structurally Ordered Model Catalysts for Oxidative Dehydrogenation: Allen G. Sault, SNLBismuth Molybdates and Magnesium Vanadates

7 in W Laser Raman Studies of VPO Catalyst Transformations Including the Zhi-Yang Xue, AmesEffect of Water Vapor

8 Simulation of the structure and properties of cobalt-substituted Neil J. Henson, LANLI aluminophosphates as potential catalysis for the selective oxidation of I

hydrocarbons

9 Separating Photocatalytic and Thermal Catalytic Effects of Acetaldehyde Kim Magrini, NRELOxidation on Platinized TIOZ

10 Zirconium-Titanium Phosphate Acid Catalysts Synthesized by Sol Gel Nancy B- Jackson, SNLTechniques

11 Preparation and Characterization of Mesoporous Synthetic Clays Kathleen A. Carrado, ANL

12 The Use of Molecular Beam Mass Spectrometry and Multivariate Data Carolyn Elam, NRELAnalysis for Rapid Catalyst Screening and Process Parameter Mapping

13 Advanced Procedures And Analytical Tools For Evaluating Catalyst Gordon J.J. Bartley, SRIPerformance

14 Enhancement Of Catalytic Properties Using Surface And Interface Engineering Y. Liang, PNNL

15 A novel USY zeolite-supported Ni-Mo sulfide catalyst for environmental Li Dien, LANLclean-up

16 Tailoring Alumina Surface Chemistry for Efficient Use of Supported MoS~ Abhaya Datye, UNM

17 Chemistry of Sulfur Dioxide on Metal and Oxide Surfaces: Photoemission and Jose A. Rodriguez, BNLMolecular-Orbital Studies

18 Dechlorination of Vapor Phase Carbon Tetrachloride using Zero Valent Iron Daniel Blake, NREL

19 Quantitative X-ray Diffraction Methods Applied to Problems in Linda D. Mansker, UNMHeterogeneous Catalysis: Characterization of Iron Fischer-Tropsch Catalysts

20 IGnetic Modeling of Hydrogen Oxidation and Ignition on Pt Srinivas Tummala, LANL

21 Reduction of NOx Emissions for Lean-Bum Engine Technology: A T. J. Gardner, SNLCooperative Research Effort Between the National Laboratories and the U.S.Auto Industry

22 Microchannel Catalytic Reactors for Fuel Processing Applications Yong Wang, PNNL

23 User Facilities for Catalysis Research in the Environmental Molecular Charles H.F. Peden, PNNLSciences Laboratory

24 AsymmetricHydrogenationCatalystsSupportedon MesoporousMaterials FrancisM. de Rege,LANL25 BatchMicroreactorStudiesof Base CatalyzedLignin and LigninModel Jim Miller, SNL

CompoundDepolymerizationin AlcoholSolvents26 LateMetalCoordinationChemistryof a ‘BulkyCO’ analog, [P(NRAr)2]+ MichaelB. Abrams,LANL27 I New C2-Symmetric Diamines Via Reductive Coupling Of Imines Using I Charles A. G. Carter, LANL

I Diboron Compounds I28 I C-H and B-C Bond Activation and C-C Coupling Reactions with Cationic I Wayde V. Konze, LANL

Platinum Complexes29 Sigma-Bond Coordination to Cationic Organometailic “Superelectrophiles” Gregory J. Kubas, LANL

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# Title Presenter

30 The Catalytic Reduction of Azides and Hydrazines Using High-Valent R. Gregory Peters, LANLOr.anouranium Comple~es

31 Biomimetic Oxidation Studies: Alkane Functionalization in Aqueous Solution Richard H. Fish, LBNL

Utilizing Insitu Formed [Fe~O(q 1-H20)( q 1-0Ac)(TPA)2]3+, as an MMO

Model Precatalyst, Embedded in Surface Derivatized Silica and Contained inMicelles -

32 Gas Phase Micelles as Micro-reactors for Oxo Catalysis David E. Fremgen, Argonne,33 Biphasic Catalysis In Water/Carbon Dioxide Micellar Systems Gunilla B. Jacobson, LANL

34 Dense Phase Dimethyl Ether As A Solvent For Homogeneous Palladium Nathan Josephson, LANLI Catalvzed Carbon-Carbon Cross Couriin~ Reactions I -

1Theoretical Studies of Catalysis at Ti Sites in Zeolites

P. Jeffrey Hay and Neil J. Henson

Theoretical Division,MSB268,LosAlamosNationalLaboratory,LosAlamos,NM87545

The Ti-containing zeolite TS- 1 is an effective catalyst for a variety of processes including selective oxidation ofolefins by H202. The nature of the Ti sites in zeolite TS- 1 and the resulting species formed by reaction withoxidants are examined using theoretical techniques. Cluster models are used to represent the atoms in the vicinity ofthe Ti active site in the silicate lattice. These approaches include ab initio density functional theory, semi-empiricalmethods, and classical simulations.

2Structural Aspects Of Titanium Sites In TitanosiIicates

C. A. Hiiar, R. Jacubinas,t and K. C. Ott*MS J5 14, Los A1amos National Laboratory, Los Alamos, NM 87545

The titanosilicalite TS-I has proven to be one of the most interesting catalysts discovered in the last decade. TS-1 catalyses the epoxidation of olefins with aqueous hydrogen peroxide under mild conditions, and has foundcommercial application in Europe for the hydroxylation of phenol. In spite of the commercial and scientific interestin TS- 1 and its analogs, very little is known of the location and nature of the Ti in the silicate framework. This lackof direct knowledge of structural details is largely due to the low concentration of Ti in the catalyst, and because theTI is likely disordered among the 12 crystallographic T sites of the MFI framework. Indeed, theoretical calculationsof theTi siting in the MFI frameworkhavepredicteda randomdistributionof Ti amongthe 12sites.

Isotopesof Ti and Si havesignificantlydifferentnuclearpropertiesin their interactionswith neutrons,givingriseto potentiallyusefulcontrastbetweenSi and Ti in a neutrondiffractionexperiment. We attemptedstructuralanalyses of titanium silicalite-1 (TS-I ) and iron silicalite-1 (FeS-1) using neutron powder diffraction techniques inorder to ascertain the location of the titanium and iron cations within the MFI zeolite framework.

Three different samples of TS-I and one of FeS-l, synthesized with gel ratios of 20:1 and 30:1 (2 samples) Si:Tiratios and a 70:1 Si:Fe ratio, were analyzed using powder neutron diffraction experiments. All the samples had theorthorhombic MFI structure with space group Prima. Five of the twelve silicon sites (T3, T7, T8, TIO, and T12), forone of the 30:1 samples, were found to contain appreciable amounts of titanium. The 20:1 and the second 30:1samples were equivalent except that they did not possess titanium on T7. For the FeS-l sample, the iron was foundto reside on one of the five sites (T8) determined for TS-I.

We will discuss the implications of the non-random siting of Ti and Fe in the MFI framework on the synthesis ofTS-I and the catalysis by Ti in microporous frameworks.

3Kinetics Of Hzsm-5 Deahtmination In Steam.

Craig D. Hughes, Morton Thiokol Corporation, Salt Lake City, Utah, Andrea Labouriau, Susan NeugebauerCrawford, Robert Romero, William L. Earl, Chemical Science and Technology Division, Los Alamos NationalLaboratory, Jason Quirin, Department of Chemical Engineering, Northwestern University, Evanston, Illinois,

We have measured the dealumination of HZSM-5 in steam. To obtain quantitative data we constructed a carefullycontrolled steaming apparatus and we have developed accurate, quantitative 27A] MAS NMR techniques foranalysis. The results of steamingat 773, 873, and 973 K indicatethat the dealuminationkineticsare nonlinear,i.e.,they do not follow a single rate law. The average activation energy obtained for the dealumination of HZSM-5 is 65k.llmol.

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Probing the Structure Of Metal-Substituted Molecular Sieves By Solid-State Nrnr.

Andrea Labouriau, Susan Neugebauer Crawford, Kevin C. Ott, And William L. Earl,Chemical Science and Technology Division, Los Alamos National Laboratory,

Los Alamos, New Mexico 87545

We have used the paramagnetic influence of metals in A1P04 and TS-1 to obtain information about the state of themetal in substituted molecular sieves. The hyperftne interaction produces chemical shifts and broadening that aredifferent from the dipole interaction, which obtains when the metal is simply exchanged in the pore. Our datastrongly indicate that the titanium in TS- 1 is substituted in the framework. We propose to use this technique toprobe the position of the metal in other metal substituted zeolites.

5Probing Zeolite Internal Structures Using Very Low Temperature 129xe Nmr.

Andrea Labouriau, Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos,New Mexico 87545, Tania Pietrass& Department of Chemistry, New Mexico Institute of Mining and Technology,

Socorro, New Mexico 87801, SusanNeugebauerCrawford,WilliamA. Weber,GhanshamPanjabi, BruceC. Gates,AndWilliamL. Earl, Departmentof ChemicalEngineeringand MaterialsScience,Universityof California,Davis,

California95616

We have measured the 129Xe chemical shift of xenon in very well characterized zeolite Y as well as in samples ofzeolite Y containing small metal carbonyl clusters, i.e., [Ir4(CO) 12], [Ir6(CO) 16], [Rh6(CO)l 6]. Each of thesupported metal carbonyl clusters was decarbonylated to give supported clusters modeled on the basis of extendedX-ray absorption fine structure spectroscopy as Ir4, Ir6, and Rh6. By measuring the chemical shifts over anextremely wide temperature range, the data are interpretable in terms of very simple models that yield effective vander Waals attraction energies.

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6Structurally Ordered Model Catalysts for Oxidative Dehydrogenation:

Bismuth Molybdates and Magnesium Vanadates

Allen G. Sault* and Judith A. Ruffner:, Sandia National Laboratories*New Materials Modeling and Validation Department, ‘Electronic and Optical Materials Department, Sandia

National Laboratories, Albuquerque, NM 87185-1349

A fundamental understanding of the nature of the active sites in mixed metal oxide selective oxidationcatalysts would greatly facilitate continued improvements in these materials. Unfortunately, the complex nature ofthese materials makes fundamental studies of the active sites difficult. The use of single crystal surfaces toovercome this complexity is limited by the insulating nature of bulk oxides, which prevents the use of manycommon surface analytical probes. For simple oxides, various workers have grown thin epitaxial films that do notsuffer from the charging problems arisin~ from the insulating nature of the bulk oxides. Such films allow scanningtunneling microscopy (STM) studies that provide an unprecedented level of atomic detail regar~ing metal oxidesurfaces. We are employing similar methods to study the surfaces of mixed metal “oxide catalysts. Using sputterdeposition, we are growing thin films of Mgs(VOQ)zand BizMoz09. two materials known to be active selectiveoxidative catalysts. Using a variety of surface and bulk analytical tools, we will demonstrate the growth ofstoichiometric, ordered, oriented films of these materials, and report preliminary observations of the surfacestructure of the films. Furthermore, we will report on changes induced in the films by treatment in reactiveenvironments (e.g., oxygen/ethane mixtures), and show that the changes are consistent with the known mechanismfor catalytic oxidation, which involves incorporation of lattice oxygen into the products.ReferencesW. Weiss,M. Ritter,D. Zscherpel,M. SwobodaandR. Schlogl,~. Vat. Sci. Tech.. A16(1998)21IF. Libuda,F. Winkelmann,M. Biiumer,H.-J.Freund,Th.Bertmms,H.NeddenneyerandK.Miiller,&@ace .$ci.318(1994)61.X.Xu,S.OhandD.W.Goodman.Lmgmir. 12(1996)4877.

7ZnSitu Laser Raman Studies of VPO Catalyst Transformations Including the Effect of Water Vapor

Zhi-Yang Xue and G. L. SchraderAmes Laboratory-USDOE and Department of Chemical Engineering, Iowa State University, Ames,IA50011

In situ laser Raman spectroscopy was used to investigate the phase transformations among various VPOcatalyst phases under transient operation conditions or under the effect of water vapor.

The transformation of (VO)ZPZOTin a series of 30 min air – 30 min n-butane(5%vol)/N~ steps at 400°C wasstudied. It showed that rxI1-and 6-VOPOAand ultimately ~-VOPOQwere produced in oxidation steps, while thesephases could be eliminated in reduction steps.

The transformation of (VO)ZPZOTin butane(2%)/HZO(5’%)/air at 400”C demonstrated that distinctiveRaman bands emerged at 994, 704, 528, 480,404, 285, and 147 cm-l after several hours in reaction. These bandsare clearly due to crystalline V205. This transformation is reversible at lower temperatures. However, VZ05 was thefinal product of (VO)ZPZOTtransformation after a prolonged treatment in water vapor. Similar observations havebeen obtained for al-, an-, 13-,5-, Y-VOP04 when they were treated in HzO(5%-1O’%YNZat 400-600°C.

A model for VPO transformations to VZOj is proposed: 1) the presence of water creates oxygen vacanciesat V-O-P sites and separates VOXand POXspecies; 2) VOXgroups restructure to form VZ05;and 3) POXgroupsmigrate to the catalyst surface and escape to the environment,likely in the form of acid phosphates. The resultssuggest thatVPOcatalystdeactivationmayoccureitherdue to oxidation of (VO)2P207to V5+phases or due tophosphorus depletion after prolonged exposure to reducing atmosphere or moisture.

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8Simulation of the structure and properties of cobalt-substituted ah.uninophosphates as potential catalysis for

the selective oxidation of hydrocarbons.

Neil J. Henson, P. Jeffrey Hay and Antonio Redondo.Theoretical Division, Los A1amos National Laboratory, Los Alamos, NM 87545.

The introduction of transition metal atoms into zeolites offers the prospect of combining the known proclivities ofthese elements for heterogeneous catalysis with the shape-selective properties of the microporous structures.

The cobalt-substituted series of aluminophosphates (COAPOS) offers the possibility of redox behaviour betweenCo(II) and Co(III) as well as a wide variety of coordination environments. An in-situ EXAFS study has beenperformed which suggests that the extent of this oxidation is dependent on the AIPO framework structure. Also,there is the question of whether Co(III) can exist in a tetrahedral geometry, since there is only one known compoundwhich contains tetrahedral Co(III); The EXAFS study suggests a structure with three short and one long bonds.

In an attempt to investigate possible geometries for cobalt in a zeolite-like environment, quantum mechanicalcalculations were performed on a number of representative clusters. Since the local geometry about cobalt isrelatively uncertain. Mott-Littleton defect calculations were performed using empirically-fit shell model potentials toobtain realistic clusters. Quantum mechanical calculations were performed to investigate the local geometry forsystemscontainingCo(II),Co(II) plus a bridgingproton and Co(III) in a tetrahedralframeworksite, and the resultscompared to experimental data on condensed phase cobalt oxides and to EXAFS data on COAPOS.

Separating Photocatalytic and Thermal Catalytic Effects ofAcetaldehyde Oxidation on Platinized TiOz

J. Falconer and K. Masmini,National Renewable Energy Lab, Golden, CO, 80401

Interest is growing in the application of photocatalytic oxidation (PCO) to cleaning VOC-containing air incommercial and residential buildings. PCO is generally used at ambient temperatures to treat low concentrations ofamenable VOCS like trichloroethylene and ethanol. We have found that the addition of moderate heat and smallamounts of platinum to the TiOz photocatalyst significantly improves the destruction rates of more difficult to treatcompounds like acetaldehyde and styrene. The work presented here quantifies the contribution of both thermaloxidation and photocatalytic oxidation of acetaldehyde in air. We found that at 140 C the sum of rate of thephotocatalytic and thermal catalytic reactions is greater than the rate achieved with either reaction alone. Themethodology developed for this work can also be used to quantitatively evaluate the efficiency of photocatalyticmaterials for various applications. We will discuss the photo- and thermal-catalytic oxidation of acetaldehyde andthe catalyst evaluation method.

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10Zirconium-Titanium Phosphate Acid Catalysts Synthesized by Sol Gel Techniques

Nancv B. Jackson, Steven G. Thoma, and Tina M. NenoffSandia National Laboratories, PO Box 5800,MS0710, Albuquerque, NM 87185, U. S.

Mixed metal phosphates, primarily zirconium and titanium, were synthesized from alkoxide starting materials withHsPO~ and HZOused as gelling agents. The materials were dried and then either calcined directly or further treatedwith sulfuric acid before calcining. Our method of sulfating the catalyst leads to incorporation of sulfate into thebulk of the catalyst and not just on the surface. The measurement of acidity was achieved by using the isomerizationof an olefin as a model reaction. A method for preventing the condensation of the crystal structure during exposureto high temperatures was to use HZS03 along with phosphoric acid as a gelling agent either during initial synthesisor by dissolving the amorphous phosphate in sulfuric acid later. Sulfonation created a solution of metal phosphatesand metal sulfates in our catalyst which increased the proportion of amorphous to crystalline regions in the materialeven after treatment at high temperatures. The sulfated titanium-zirconium phosphates were much more activeinitially than the non-sulfated catalysts. However, they deactivated much more quickly than the Ti-Zr phosphates ascan be seen from the figure. The sulfate in the catalyst will reduce and desorb in a reducing atmosphere at lowtemperatures (400 K), but in oxidizing or neutral environments the sulfate will remain on the catalyst surface up to673 K.

11Preparation and Characterization of Mesoporous Synthetic Clays

Kathleen A. Carrado and Langqiu XuChemistry Division 200, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439

Mesoporous synthetic clays (MSCS) are obtained when polymer-containing silicate gels are hydrothermallycrystallized to form layered magnesium silicate hectorite clays containing polymers that are incorporated in situ. Inthis in situ technique, interlayer intercalation of different polymers over broad molecular weight and concentrationranges is achieved. The polymer loading of synthesized composites is determined by thermal analysis, and the basalspacing changes resulting from different levels of polymer intercalation are monitored by X-ray powder diffraction.In some cases intercalation occurs to such a degree as to delaminate the layers and cause loss of stacking registry.Polyvinylpyrrolidone (PVP) of several average molecular weights ranging from IOK to 1-3M, in loadings varyingfrom 10-20 wt%, were used. The organic polymer template molecules were removed from synthetic polymer-claycomplexes via calcination. Pore radii, surface areas, and pore volumes of the resulting porous inorganic networks(mesoporous synthetic clays ) were then measured. A direct correlation betwee~ both PVP Mw and polymerloading on the diameter of the average pore was found, which varied from 40 to 100A. Samples have been tested inpreliminary hydrodesulfurization experiments for reactivity and selectivity of dibenzo-thiophene to biphenyl, incollaboration with C. Marshall (ANL).

Acknowledgement This researchwas performedundertheauspicesof the U.S. Dept.of Energy,Office of Basic EnergySciences,DivisionofChemicalSciences,undercontractno. W3I-109-ENG-38.

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12The Use of Molecular Beam Mass Spectrometry and Multivariate DataAnalysis for Rapid Catalyst Screening and Process Parameter Mapping

Robert Evans and Carolyn Elam, NREL

In the search for economic routes to fuels and chemicals from renewable resources, rapid-analysistechniques are critical for screening new approaches for technical feasibility as well as guiding subsequentengineering-scale experiments. NREL has used molecular beam mass spectrometry (MBMS) to study theconversion of biomass and polymers by pyrolysis, partial oxidation and heterogeneous catalysis. The objective ofthis approach is to identify process conditions that lead to higher selectivity than is normally achieved in these hightemperature processes. An example is the generation of propylene and butylenes and CO and Hz from mixtures ofcellulose and polyethylene by catalytic partial oxidation. Using milligram-scale experiments over five days, thepartial oxidation of eight feedstocks and twenty catalysts were screened for their relative catalytic crackingperformance in this context. Four of these catalysts were then subjected to parametric studies to evaluate the effectsof temperature, oxygen concentration. steam and contact time. Multivariate data analysis (MVA) techniques wereused to follow the major trends in the data and identify promising catalysts and operating conditions. The MBMS/MVA approach could be used as the basis for combinatorial studies of heterogeneous catalysis.

Advanced Procedures And Analytical Tools For Evaluating Catalyst Performance

Gordon J.J. Bartlev, Cynthia C. Webb, William D. DiSilverio, Bruce B. Bykowski, Melvin N. Ingalls, SouthwestResearch Institute, P.O. Drawer 28510, San Antonio, Texas 78228-0510

A test apparatus that uses a fuel burner to generate the heat and appropriate exhaust gas components”to providelubricate free, simulated engine exhaust was developed to independently study the impact of fuel constituents (e.g.,sulfur, MMT) and lubricating oil additives (e.g., phosphorus, calcium) on aftertreatment systems such as catalyticconverters. In addition to varying fuel properties for study, studies examining the effect of lubricating oilcomposition or oxidation state (unburned, partially burned, or completely burned) can be performed under aprecisely controlled environment. Since the FOCAS (Fuel/Oil Catalyst Aging System) utilizes full-sized catalyticconverters, accelerated catalyst aging also can be performed analogous to aging performed using an engine, but withless test-to-test variation.

A flexible exhaust engine rig (FLEXER) can be used as a cost-effective method for screening potentialaftertreatment system components prior to evaluation over vehicle driving cycles. The test bed includes hardwareand software that allows both steady state and transient control of engine exhaust temperature and flow, as well asquasi-independent flexibility to alter the exhaust emissions character.

Aftertreatmentcomponentmanufacturersare beingrequirednot only to developexhaustsystemcomponents,butto integrate these components into the enginelvehicle calibration. A computer-controlled system EmissionsReduction Intercept and Control (ERIC) has been developed to intercept and modify the vehicle controls to optimizethe exhaust character for a specific aftertreatment device, to yield the lowest emissions possible.

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Enhancement Of Catalytic Properties Using Surface And Interface Engineering

Y. Liang,J.L. Daschbach,S.A. Chambers,Y. Su, A.G.Joly, D.R. Baer, Y. WangPacific Northwest National Laboratory *, P.O. Box 999, MS KS-93, Richland, WA

M.H. Na, H. LuoState University of New York, Buffalo, NY

In this presentation, we report two approaches that may be used to enhance catalytic properties of selectedmaterials. The first approach involves the use of stepped TIOZ surfaces to stabilize Rh clusters on TiOZ surfaces.Although Rh has been widely used in many catalytic reactions , glomeration of Rh clusters on supported surfacesometimes occurs. We have used STM and XPS to examine the distribution and electronic structures of Rh clusterson TiOz surface. STM results showed that Rh clusters -~ew preferentially along the step edges on the vicinalTiOz(l 10) surfaces. XPS of Rh core level and valance-band structure showed no evidence of change in electronicstructures of Rh clusters. The results suggest that the vicinal TiOZ(110) surface provides a more stable support fornano-sized Rh clusters.

Our second approach involves the use of interracial engineering to tailor the catalytic properties of photocatalystsand to enhance the solar spectrum response. We use CdSe/ZnTe and SnOz/130z heterostmctures as examples.Based on photoluminescence, photo- current-voltage, and photoexcited electron-hole pair lifetime measurements onCdSe/ZnTe, we show such a structure enhances the use of solar energy by using a smaller bandg.ap material bettermatched to the solar spectrum as a sensitizing layer for a wider bandgap materials. Such a configuration alsoprolongs the electron-hole pair lifetime by spatially separating photoexcited electrons and holes in the inter-facialregime. Primary results on photocatalytic reaction show that compare to TiOZ powders, the hydrogen productionfrom photocatalytic water cleavage increases by nemly 100% with the presence of sno~~io~ catalyst.

PacificNorthwestLaboratoryisa multipro:ramnationallaboratoryoperatedfortheU.S.DepartmentofenergybyBattelleMemorirdtnsrituteunderContractDE-AC06-76RL01830.

15A novel USY zeolite-supported NhMo sulfide catalyst for environmental clean-up

Li DienEES-1, MS D462, Earth and Environmental Sciences Division

Los Alamos National Laboratory, Los Alamos, NM 87545

New environmental regulations require that sulfur, nitrogen and toxic metals in fuels used be reduced verysignificantly. The y-AJ@3 b~ed catalysts which have been widespread used in industry are not suitable for deep

hydrodesulfurization (HDS). Zeolite supported transition metal sulfides may be new generation catalysts for thedeep HDS, because of their high activity in both hydrogenation and hydrocracking (HC). A novel uhrastable Y-type(USY) zeolite supported Ni-Mo sulfide catalyst has been developed in this work.

The USY zeolite was made by dealumination of NaY zeolite (faujasite). The USY and NaY zeolite supported Ni-Mo catalysts were prepared by co-impregnation of Ni and Mo aqueous ammonia solution. The catalysts were dried

at 200°C for 2h, calcined at 550”C for 3h in air, and sulfided under a stream of HZ-HZS mixture at 400”C for 2h

before reactions. The catalytic HDS of dibenzothiophene (340”C) and HC of decalin (340”C), tetralin (375”C) anddiphenylmethan (375”C) were tested. The catalytic activities were calculated based on gas chromatographymeasurements. The catalysts were characterized using powder x-ray diffraction (XRD), NH3 temperatureprogrammed resorption (TPD), diffuse reflectance spectroscopy (DRS), x-ray photoelec~on spectroscopy (XPS)and transmission electron microscopy (TEM).

USY zeolite and its supported Ni-Mo sulfide catalyst are much active for the tested reactions than NaY and itssupported catalyst, respectively. The USY zeolite supported Ni-Mo catalyst also has much higher HDS and HC

activity thany-A1203supportedcatalyst.The NH3TPD indicatedthe presenceof a very strong Bronstedacid site inthe USY zeolite. XPS, DRS and TEM showed that Ni and Mo may enter the sodalite cage or great cavity of theUSY zeolite. Both strong Bronsted acid structure and the Ni-Mo sulfide phase in the cage or supercage of USYzeolite may contribute to the high HDS and HC activities of USY zeolite supported Ni-Mo sulfide catalyst.

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16Tailoring Alumina Surface Chemistry for Efficient Use of Supported MoS2

John Reardon and Abhava K. Datve, Department of Chemical and Nuclear Engineering, University of New Mexico,Albuquerque, NM 87131-1341 and Allen G. Sault, New Materials Theory and Validation Department, Sandia

National Laboratories, Albuquerque, NM 87185-1349

Hydrodesulfurization (HDS) over MoSjy-A1203 catalysts shows a maximum in specific activity with increasing

Mo loading. In contrast, monotonic decreases in specific activity are observed over other supports. While earlierwork ascribes these differences to different MoS~ morphologies, our activity measurements and transmission

electron microscope images demonstrate that the different trends can occur on catalysts with identical MoS2morphologies. We therefore propose an alternative explanation for the activity trends involving the formation of

inactive molybdate species on y-A1203 at low coverages. Reaction of molybdates with the highest frequency OH

groups on y-A1203 forms stable M004Z- species at low Mo coverages, that are difficult to convert to MoS2. As a

result, HDS activity is low. As Mo coverage increases the highest frequency OH groups are consumed, formation ofeasily sulfided molybdate species begins to predominate, and activity increases. Ultimately, activity goes through a

maximum as the MoS2 platelets grow with increasing Mo loading. Since the highest frequency hydroxyls on ‘y-Al~03 are associated with tetrahedrally coordinated Al cations, it should be possible to prevent the formation of

inactive molybdates and eliminate the maximum in activity by removing all tetrahedrally coordinated Al cations

from the support surface. This removal has been accomplished through the use of ct-Al~03, which contains only

octahedrally coordinated Al atoms, and through titration of the highest frequency hydroxyls with titanium

isopropoxide. In both cases, no maximum in activity is observed and activity at all MO loadings is higher than on Y-Al~03. Fourier transform infrared and X-ray photoelectron spectroscopy measurements will be presented to support

this explanation.

17Chemistry of Sulfur Dioxide on Metal and Oxide Surfaces:

Photoemission and Molecular-Orbital Studies

Jose A. Rodriguez, Tomas Jirsak, S. Chaturvedi, and Jan HrbekDepartment of Chemistry, Brookhaven National Laboratory

Sulfur dioxide is one of the major air pollutants released to the atmosphere as a result of volcanic activity and thecombustion of fuels in power plants, factories, houses, and transportation. After its oxidation and reaction withwater in the atmosphere, it is responsible for the acid rain that leads to the corrosion of many metals. Moreover, thecatalytic activity of most transition metals is drastically reduced by the presence of SOZ or other sulfur containingmolecules in the feed. In an ongoing project, we are investigating the surface chemistry of S02 on well-definedsurfaces of metals and oxides using synchrotron-based high resolution photoemission and ab initio SCF calculations.On these systems, sulfur dioxide dissociates (SOZ+ S, + 20.) or transforms into SOj or SOd. It was found thatadsorption geometries in which SOZ is di-coordinated via 0,0 or S,0 are the most probable precursors fordissociation. No evidence was found for the existence of SO as a stable product. The chemical reactivity of theexamined metals increased following the sequence: Pt = Rh < Ru c Mo c Cs/Mo c Cs. Cs adatoms were veryeffective for enhancing the dissociation rate of SOZon metal and oxide surfaces.

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18Dechlorination of Vapor Phase Carbon Tetrachlonde using Zero Valent Iron

K. Ma@ni, R. Rabago,S. Preis, and Daniel.BlakeNationalRenewableEnergyLaboratory,1617Cole Blvd., Golden,CO 80401

Carbon tetrachloride (CC14)is one of the most refractory hazardous organic compounds that has been released intothe environment, and is a widespread pollutant at Department of Energy and Department of Defense sites. Of thetechnologies that have been explored to destroy chlorinated organic compounds, many have significant difficultytreating CC14. Extensive literature exists on treating halogenated organic compounds in groundwater with zerovalent iron, but very little work has been done to explore its use in treating vapor phase CC14. We are workhg onthe gas-phase destruction of carbon tetrachloride at mild temperatures (<250 C), with solid iron surfaces, andvariable atmospheres that include oxygen, in a single-pass reactor. Reaction conditions determine productdistributions that include chloroform, methylene chloride, carbon monoxide, and carbon dioxide. CC14destructionefficiencies of 90% have been achieved. We will present recent results describing the optimization of this gas-phase,Fe-based process.

19Quantitative X-ray Diffraction Methods Applied to Problems in Heterogeneous Catalysis: Characterization

of Iron Fischer-Tropsch Catalysts

Linda D. Mansker and Abhaya K. DatyeUniversity of New Mexico, Chemical and Nuclear Engineering Department

Albuquerque, NM 87131-1341

X-ray diffraction is a woefully underused solid materials characterization technique. It is quite sensitive tocomposition, and when applied properly, can be used to determine particle size distributions, as well asdomain/crystallite sizes, particle shapes, structural defects, and structural changes over time, temperature orpressure. X-ray diffraction is also tolerant of the sample matrix, thus it can be used to study problems inheterogeneous catalysis which previously have been called ‘intractable’, such as the nature of the working iron F-Tsynthesis catalyst. We have shown ‘].’. 3) that the working catalyst can be examined in the product wax, whichpreserves catalyst composition and morphology, if samples are obtained under inert atmosphere. We will also showthat we can determine a great deal of information about catalyst and product composition and morphology. X-raydiffraction data obtained from the working iron F-T catalyst are analyzed using rigorous solid state and structuralanalysis techniques. The results are compared with neutron diffraction, TEM, and MES data, then with the observedkinetics. We then draw conclusions about active phase components, catalyst efficiency and catalyst lifetime.

(1) Jackson, N. B., Mansker, L. D., O’Brien, R. J., Davis, B. H. and Datye, A. K., Studies in Surface ScienceandCatatysis,111 (1997)501.(~) Mmsker,L,D.,Jin,y.; md D~tye,A.K.;Pmt.coal Uquefaction and Solid Fuels ’97Conference proceedings,electronic publication,Federal Energies and Technologies Center,Pittsburgh.Pennsylvania(1997)httpf/www.fetc.doe.gov/evenu/97conferences/cod_li@97cl_pdf/datye.pdf/.(3) Mansker,L.D.,Jin, Y.; and Datye,A. K.: submittedforpublication,specialissueon Fischer-Tropschsynthesis,Journalof AppliedCatalysis.

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20Kinetic Modeling of Hydrogen Oxidation and Ignition on Pt

David K. Zerkle and Srinivas TummalaLos Alamos National Laboratory, Chemical Science and Technology Division

P.O. Box 1663, Mail Stop J567, Los Alamos, NM 87545Mark D. Allendorf

Sandia National Laboratories, Combustion Research FacilityP.O. Box 969, Mail Stop 9052, Livermore, CA 94551-0969

The surface chemical kinetic mechanism for hydrogen oxidation on platinum is basic to the simulation of a widevariety of catalytic processes. In this work we present a detailed mechanism, which serves to unify severalmechanisms that have been published recently and have been developed for different applications. The currentmechanism has been applied to the simulation of low pressure hydrogen oxidation and water decomposition in aperfectly stirred reactor at temperatures ranging from 1200-1700 K. The agreement with the experimental data forthis configuration is outstanding. To demonstrate that the current mechanism indeed reconciles the fundamentaldifferences between existing mechanisms, we have applied it without modification to the simulation of hydrogenignitio~extinction behavior in stagnation fIOW on platinum at atmospheric pressure. The agreement with the

experimentally determined ignition temperatures is excellent across a broad range of reactant mixtures. We proposethat this new mechanism possesses the broad applicability required to serve as the basic mechanistic element in themore complex kinetic sets needed for simulating a wide variety of catalytic processes involving hydrocarbons.

21Reduction of NOX Emissions for Lean-Burn Engine Technology: A Cooperative Research Effort Between the

National Laboratories and the U.S. Auto Industry

T. J. Gardner, L. I. McLaughlin, and R. S. Sandoval, Sandia National Laboratories+;J. G. Reynolds, Lawrence Livermore National Laboratory

K. C. Ott, and M. T. Paffett, N. C. Clark, and J. A. Rau, Los Alamos National Laboratory; andR. G. McGill, N. Domingo, J. Storey, and K. L. More, Oak Ridge National Laboratory

This project is sponsored by the Office of Advanced Automotive Technologies at DOE (DOE/EE/OIT/OAAT) andinvolves cooperative research and development agreements (CRADAS) between four national laboratories (LosAlamos National Laboratory [LANL], Lawrence Livermore National Laboratory [LLNL], Oak Ridge NationalLaboratory [ORNL], and Sandia National Laboratories [SNL]) and the Low Emission Technologies Research andDevelopment Partnership (LEP, composed of Chrysler Corporation, Ford Motor Company, and General MotorsCorporation). The project addresses reduction of compression ignition direct injection (CIDI) engine NOXemissions using exhaust aftertreatment - identified as one of the key enabling technologies for CIDI engine success.The overall CRADA efforts are focused on the development and evaluation of new catalyst materials for reducingNOX emissions, specifically targeting the selection of appropriate catalyst materials to meet the exhaustaftertreatment needs of the PNGV vehicles.

Lean-burn NOX reduction catalyst development efforts have focused on hydrous metal oxide-supported catalysts(SNL), aerogel-derived catalysts (LLNL), and zeolite-based catalysts (LANL). Both precious metal and non-precious metal catalysts active for NOX reduction are being investigated. ORNL has provided real-worldcharacterization of catalyst performance in an engine laboratory in addition to microstructure characterization ofcatalysts using electron microscopy. Selected full-size national laboratory and catalyst supplier-fabricated catalysts

have been evaluated, using various hydrocarbon reductants (propylene, hexadecane, ultra-low sulfur diesel, andconventional diesel fuel).

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22Microchannel Catalytic Reactors for Fuel Processing Applications

Anna Lee Y. Tonkovich, Jennifer L. ZXka, Sean P. Fitzgerald, Michael J. LaMont, Robert S. Wegneg, David PVanderWiel, Ed G. Baker, Yotw Watw

Pacific Northwest National Laboratory, Richland, WA.99352

A fuel processor is a critical reactor technology for the deployment of PEM-based fuel cells for both portable andstationary applications. The fuel processor produces hydrogen rich streams from hydrocarbon-based feedstocks in a

multi-step process (fuel vaporizer, primary conversion reactor to produce synthesis gas, water gas shift reactor, andCO clean-up reactor). Conventional fuel processing technology is based on fixed-bed reactors, which do not scalewell with the small modular nature of fuel cells. Microchannel catalytic reactor-based fuel processors, however, are

small, efficient, modular, lightweight, and potentially inexpensive. Microchannel reactors also reduce heat and masstransport limitations for reactions, and thus facilitate exploring and deploying reactions with fast intrinsic kinetics.The recent results for fuel vaporizer, primary conversion, and water-gas shift reactions will be discussed.

23UserFacilities for Catalysis Research in the Environmental Molecular Sciences Laboratory

Charles H.F. Peden, Pacific Northwest National Laboratory*~ Richland, Washington

The William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), the Department of Energy’snewest national scientific user facility, is located at Pacific Northwest National Laboratory (PNNL) in Rlchland,Washington. The EMSL is operated by PNNL for the DOE Office of Biological and Environmental Research.

As a national scientific user facility, the mission of the EMSL is to:. provide advanced and unique resources to scientists engaged in research on critical

problems in the environmental molecular sciences● educate young scientists in the molecular sciences to meet the demanding

environmental challenges of the future.As a research organization, the EMSL seeks to:

● attain an understanding of the physical, chemical, and biological processes needed tosolve critical environmental problems

● advance molecular science in support of the DOE’s long-term environmental mission.This poster will describe EMSL facilities that are particularly useful for catalysis research.

*Pacific Northwest National Laboratory is a multi-program national laboratory operated for the U.S. Departmentof Energy by Battelle Memorial Institute under contract number DE-AC06-76RL0 1830.

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24Asymmetric Hydrogenation Catalysts Supported on Mesoporous Materials

Francis M. de Recze,David K. Morita, William Tumas and Kevin C. Ott*MS J5 14, Los Alamos National Laboratory, Los Alamos NM 87545; email: fmderege tl?lanl.gov

The ability to alter catalyst design parameters such as curvature and charge on surfaces such as MCM-41 providesan ideal mechanism to probe various homogeneous catalysts that can be supported on this medium. The pore sizeand charge of the solid supports can be varied systematically by the choice of template and aluminum content usedin the synthesis gel respectively. Enantioselective hydrogenation reactions are extremely ligand and substratedependent and appear to be an ideal systems to be studied. We have examined a number of approaches tosupporting rhodium catalysts on MCM-41 having varying pore size and aluminum content, for the hydrogenationreaction of various enamide substrates. We will discuss the chemistry of the catalyst-support interaction, catalyticresults, and catalyst stability.

25Batch Microreactor Studies of Base Catalyzed Lignin and Lignin Model Compound

Depolymerization in Alcohol Solvents

James E. Miller, Lindsey Evans, Dan Trudell, Alicia Littlewolf, Matthew LopezSandia National Laboratories, AlbuquerqueNM87185

The depolymerization of organosolv-derived Iignins by bases in methanol or ethanol solvent was studied in rapidlyheated batch microreactors. The conversion of lignin to ether solubles by KOH in methanol or ethanol was rapid at290 ‘C, reaching the maximum value within 10-15 minutes. An excess of base relative to lignin monomer units wasrequired for maximum conversion. Strong bases (KOH, NaOH, CSOH) convert more of the li.gninto ether solublematerial than do weaker bases (LiOH, Ca(OH)Z, and Na~COs). A positive synergistic effect on conversion WMobserved for a combination of NaOH and Ca(OH)z. Model compound studies confirm that the cleavage of etherlinkages is the dominant depolymerization reaction. Ring alkylation by the alcohol solvent is also observed.Ethanol and methanol are converted to acetic and formic acid respectively under the reaction conditions with anactivation energy of approximately 50 kcal/mol. This results in a loss of solvent, but more importantly neutralizesthe base catalyst, halting forward progress of the reaction.

This work was supponed by the United States Department of Energy under Contract DE-AC04-94AL850000. Sandia is a mulriprogramlaboratory operated by Sandia Corporation, a Lockheed Mwtin Company, for the United States Department of Energy.

26Late Metal Coordination Chemistry Of A ‘Bulky Co’ Analog, [P(NRar)z]+

Michael B. Abrams, Brian L. Scott, and R. Tom Baker, Chemical Science and Technology Divisioin, Los AlamosNational Laboratory, MS J5 14, Los Alamos, NM 87545 USA

The coordination chemistry of the title bulky phosphenium cations is investigated for Groups 6-10 transition metals.Reactivity with small molecules as a function of transition metal and overall charge will be discussed.

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27New C2-Symmetric Diamines V1a Reductive Coupling Of Imines Using Diboron Compounds

Charles A. G. Carter, Thomas M. Cameron, Brian L. Scott, and R. Tom Baker, Chemical Science and TechnologyDivision, Los Alamos National Laboratory, Los Alamos, NM 87545, and Stephen A. Westcott, Chemistry

Department, Mount Allison University, Sackville, NB Canada E4L 1G8

Chelating N-aryldiamines have been found to be effective ligands for both early [1] and late [2] metal-catalyzedpolymerization of trends as a function of R, Ar, and the substituents on boron will be discussed in the context of aproposed mechanism involving a sigmatropic rearrangement of the bis (imine) adduct of the diboron compound.

[1] Scollard, J. D.; McConville, D. H. J. Am. Chem. Sot. 1996,118, 10008.[2] Johnson, L. K. et al. 5th North American Chemical Congress, Cancun, Mexico 1997 Abs. #1386.

28C-H and B-C Bond Activation and C-C Coupling Reactions with Cationic Platinum Complexes

Wayde V. Konze, Gregory J. Kubas, Brian L. Scott, Chemical Science and Technology, MS-J5 14, Los AlamosNational Laboratory, Los Alamos, NM 87545

Cationic platinum complexes of the type [WL)~(Me)(SolV)l+(BArF)- (L2 = pphJ, Et~p(CH~)~pEt~,CyzP(CHz)zPCyz, PhzP(CHz)ZPPhZ;SolV = OEtZ,CICHZC1,NC5F5)have been studied for the activation of smallmolecules. During these studies, the complex rrans-[Pt(PPhs)ZMe(OEtJ] (BArF) was found to undergo B-C bondcleavage of the B/wF (B[Cd-Is(3,5-CFs)Z]J anion under mild conditions to form the neutral, diarylated complexrrans-Pt(PPh3)z(ArF)z in good yield. This reaction demonstrates the first transition metal-mediated reaction of the“non-interacting” BArF anion which is used quite often in catalytic polymerization studies. Complexes whichcontain chelating phosphines [Pt(diphos)Me(OEtJ] (BArF) (diphos = DEPE, DCPE, DPPE) do not undergo B-Cbond cleavage, but react with arene solvents (benzene, toluene, biphenyl, m-xylene) by undergoing C-H activationand C-C coupling to generate complexes of the type [{Pt(diphos) }@-q3:T13-biaryl)](BArF)~. The biaryl ligandsexhibit a rare p-q3:q3-bis-allyl bonding mode, and can be removed from the complex with stoichiometric oxidants.The chelating phosphine complex [Pt(DCPE)Me(OEtz)] (BArF) activates a C-H bond of thiophene to generate the

novel bridging 2-thienyl complex [Pt(DCPE)( p-$ C-SC4H3)]z(BtiF)z, which exhibits an unusual C, S-bound 2-thienyl Iigand. The details of these reactions are discussed, along with their relevance to catalytic C-H bondactivation and C-C bond formation processes.

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29Sigma-Bond Coordination to Cationic Organometallic “Superelectrophiles”.

Gre~orv J. Kubas, J ean Huhmann-Vincent, Wayde V. Konze, Brian L. Scott, Chemical Science and Technology,MS-J5 14, Los Alamos National Laboratory, Los Alamos, NM 87545

Coordination and activation of a bonds such as H–H in hydrogen and C–H in hydrocarbons towards oxidativeaddition on metal complexes is a critical first step in catalysis. We have been carryingout synthesis, structuralcharacterization,and comparisonsof the reactivitypatterns of dihydrogen, silanes, and germanes on new cationic16-e complexes [Mn(CO)3(PCy3)-2]+, [Mn(CO)(diphosphine) 2]+, and [Re(CO)4(PCy3)]+. These complexes, whichare stabilized by large noncoordinating anions such as B[C6H3(3,5-CF3) 2]4-, contain ag,ostic C–H interactions that

are displaced by a-ligands such as Hz. The high electrophilicity of positively-charged metal centers that containelectron-withdrawing CO enhances cxdonation from the H–H and Si–H bonds. This offsetsdecreasedbackbondingand gives unexpectedlystrong reversiblecoordination,while lessening the tendencyto undergo oxidative addition.The Re complex is the first example of a 16e tetracarbonyl mono@os@w species, an example of anorganometallic “superelectrophile”. Such metal centers -~eatly increase the acidity of bound Hz gas (e. g.[Re(CO)4(PcyJ(HZ)]+ protonates diethyl ether) and may allow isolation of metal-alkane complexes with greatly

enhanced acidity of the coordinated C–H. This may promote functionalization of methane to useful fuels orchemicals for example. Both C–H cleavage and C–C bond coupling has been observed for arene reaction withelectrophilic platinum centers, e. g. formation of biphenyl from toluene. Other possible applications ofsuperelectrophiles include room temperature hydrogen isotope and other chemical separations on surface-supported16e metal centers that reversibly bind H2 and other small molecules.

30The Catalytic Reduction of Azides and Hydrazines Using High-Valent Organouranium Complexes

R. Gre~orv Peters, Benjamin P. Warner and Carol J. Bums*Chemical and Environmental Research and Development Group (CST-18)

Los Alamos National Laboratory, Los A1amos, NM 87545

We have developed examples of well-defined catalytic processes that involve high-valent organouraniumcomplexes. The U(VI) complexes (CsMej)U(=NR)Z (R = Ph, 1; R = Ad = 1-adamantyl, 2) can be reduced with HZto the corresponding U(W) amide complexes (C5Mej)ZU(NHR)z(R = Ph, 3; R = Ad, 4). These reduced complexesmay be deoxidized by organic oxidants such as AdN3 and N,N’-Diphenylhydrazine to regenerate the U(VI) startingmaterials. Preliminary mechanistic and khtetic data of this transformation will also be presented. These reactionsare the first examples of the use of an organouranium U(IV)/U(VI) redox couple to catalyze organic transformations.These reactions also represent the first examples off-orbital participation in stabilizing intermediate complexes in acatalytic cycle.

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31Biomimetic Oxidation Studies: Alkane Functionalization in Aqueous Solution Utilizing Insitu Formed

[Fe20(ql-H20)(q l-0Ac)(TPA)2]3+, as an MMO Model Precatalyst, Embedded in Surface Denvatized Silica

and Contained in Micelles

Karine Neimann, Ronny Neumann, Casali Institute of Applied Chemistry, Graduate School of Applied Science TheHebrew University of Jerusalem, Jerusalem, Israel 91904, Alain Rabion, Lawrence Berkeley National Laboratory,

University of California, Berkeley, California, USA 94720, Groupement de recherche de Lacq, BP 34,64170 Artix,France Robert M. Buchanan, Department of Chemistry, University of Louisville, Louisville, KY 40292 and_

H Fish Lawrence Berkeley National Laboratory, University of California, Berkeley, California, USA 94720->

The biomimetic, methane monoxygenase enzyme (MMO) precatalyst, [Fe20(q ‘-H20)(q ‘-OAC)(TPA)21W(TpA =

tris[(2-pytidyl)methyl] amine), 1, formed insitu at pH 4.2 from [Fe20(p-0Ac)(TPA)2] 3+,2, was embedded in an

amorphous silicate surface modified by a combination of hydrophilic polyethylene oxide and hydrophobicpolypropylene oxide. The resulting catalytic assembly was found to be a biomimetic model for the MMO active sitewithin a hydrophobic microenvironment, allowing alkane functionalization with t-butyl hydroperoxide (TBHP)/@

in an aqueous reaction medium (pH 4.2). For example, cyclohexane was oxidized to a mixture of cyclohexanone,cyclohexanol, and cyclohexyl-r-butyl peroxide, in a ratio of -3: 1 :2. The silica based catalytic assembly showedreactivity comparable to an aqueous micelle system utilizing the surfactant, cetyltrimethylammonium hydrosulfate atits critical micelle concentration, where functionalization of cyclohexane with TBHP/0~ in the presence of 1 was

also studied at pH 4.2 and found to provide similar products, cyclohexanol, cyclohexanone, and cyclohexyl-r-butylperoxide, in a ratio of -2: 3: 1. Moreover, the mechanism for both the silica based catalytic assembly and the

aqueous micelle system was found to occur via the Haber-Weiss process; formation of both r-BuO” and t-BuOO.

radicals. The r-BuO. radical initiates the C-H functionalization reaction to form the carbon radical followed by 02trapping, to provide the intermediate cyclohexyl hydroperoxide, which produces the cyclohexanol andcyclohexanone products. These MMO, biomimetic studies were funded by the US-Israel Binational ScienceFoundationand the US DOE.

32Gas Phase Micelles as Micro-reactors for Oxo Catalysis

David E. Frem~en, Eugene S. Smotkin, Illinois Institute of Technology and Chemical Technology Division RobertJ. Klin@er, Jerome W. Rathke, Argonne National Laboratory, Argonne IL 60439

Mlcroemukiions of water in liquid and supercritical COZ me being investigated by in-sitl~ high pressure NMRspectroscopy. Microemulsions offer several advantages as media for conducting homogeneous catalytic reactions:catalyst recovery via phase separation, and enhanced mass transport rates over conventional phase transfer systems.The Fluid Catalysis Group here at ANL has previously demonstrated the hydroformylation of propylene in SCCQusing cobalt carbonyl. The hydroformylation of propylene using Rh(TPPDS) in water/scCOz micelles has recentlybeen demonstrated. Perfluorinated surfactants are being evaluated to determine micelle formation, structure, andstability. 19Fand 13Clongitudinal relaxation rates (Tl) can provide information on the dynamic behavior of themonomeric surfactants and surfactant aggregates in micelles. Cot-relation times for the reorientation of micelle tomonomer can be derived from the TI data. A B1.~adient technique is being refined for measurement of diffusioncoefficients and average micelle particle size. Transport rates can be assessed by comparison of the diffusion rates ofwater, water soluble salts, and surfactant.

1. Rathke, J. W.; tGingler, R. J.; Kmuse, T. R.; Orgunomerul/its, 199110, 1350-13552. Jacobson, G.B.; Tumas, W.; Results presented at 8th tsstematiormlSymposium on SF?XFC.

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33Biphasic Catalysis In Water/Carbon Dioxide Micellar Systems

Gunilla B. Jacobson, William Tumas,Los Alamos National Laboratory,CST-18, Los Alamos, NM, 87545

Heterogeneous catalysts currently dominate the field of large-scale industrial chemical synthesis, as the catalystcan easily be separated and reused after the reaction is complete. Homogeneous catalysts typically operate at mildertemperatures and can exhibit activities and selectivities unknown for their heterogeneous counterparts, althoughproblems associated with the separation, recovery and re-use of the highly expensive catalysts can sometimes be alimitation. Homogeneous catalysis is however widely used for specialty applications, such as production ofpharmaceuticals, where high selectivity is of great importance.

We will report on biphasic catalysis in water/carbon dioxide micelhu systems for several important reactions,includin~ hydroformylations and hydrogenations, which avoids the use of organic solvents and allows for separationand recycling of the homogeneous water-soluble catalyst. The use of micellar systems, either emulsions ormicroemulsions, results in increased reaction rates due to the large surface area and low surface tension betweenwater and carbon dioxide. Also, by using supercritical carbon dioxide as the continuous phase the micelkir systemcan easily be broken after completing the reaction, simply by decreasing the pressure, allowing for easy separationof the product from the aqueous catalyst phase. The results of several reactions will be given as a function ofsurfactant, substrate, water to carbon dioxide ratio, temperature and pressure.

34Dense Phase Dimethyl Ether As A Solvent For Homogeneous Palladium

Catalyzed Carbon-Carbon Cross Coupling Reactions

Nathan Josephson. G.H. Brown, D.R. Pesiri, D.K. Morita, W. Tumas, LANL

We will be reporting on palladium catalyzed carbon-carbon cross coupling reactions in dense phase dimethyl ether.

Densephase solventshave been studied as alternativesto conventionalorganic solvents with the added advantagesof easy separation, tune-ability and variable dielectric constant. C02 has been highly studied as an alternative non-polar solvent that also contains environmental implications. Dense phase dimethyl ether (DME) shows promise as apolar solvent for synthesis applications, and unlike most ethers DME is not susceptible to autooxidation. Thepalladium-catalyzed Stille, Suzuki and Heck carbon-carbon cross coupling reactions is investigated in DME andcompared with common organic solvents. The reaction rates for both the DME as well as the organic solvents weremeasured to show comparisons between the two solvents reaction rates. Conversions and selectivity’s will bereported to evaluate the reactivity of the palladium catalyzed reactions in both solvents to extrapolate solvent effecton product conversion.

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