+ All Categories
Home > Documents > SynthesisofSolidCatalysts...7.6.5 Unsupported Metal Sulfide Catalysts for Hydrotreating 148 7.7 New...

SynthesisofSolidCatalysts...7.6.5 Unsupported Metal Sulfide Catalysts for Hydrotreating 148 7.7 New...

Date post: 26-Dec-2019
Category:
Upload: others
View: 11 times
Download: 0 times
Share this document with a friend
30
Synthesis of Solid Catalysts Edited by Krijn P. de Jong
Transcript
  • Synthesis of Solid Catalysts

    Edited byKrijn P. de Jong

    Administrator9783527626861.jpg

  • Synthesis of Solid Catalysts

    Edited byKrijn P. de Jong

  • Related Titles

    Jackson, S. D., Hargreaves,

    J. S. J. (ed.)

    Metal Oxide Catalysis

    2009

    ISBN: 978-3-527-31815-5

    Mizuno, N. (ed.)

    Modern HeterogeneousOxidation CatalysisDesigns, Reactions and Characterization

    2009

    ISBN: 978-3-527-31859-9

    van Santen, R. A., Sautet, P. (eds.)

    Computational Methods inCatalysis and MaterialsScienceAn Introduction for Scientists andEngineers

    2009

    ISBN: 978-3-527-32032-5

    Ozkan, U. (ed.)

    Design of HeterogeneousCatalystsNew Approaches based on Synthesis,Characterization and Modeling

    2009

    ISBN: 978-3-527-32079-0

    Ding, K., Uozumi, Y. (eds.)

    Handbook of AsymmetricHeterogeneous Catalysis

    2008

    ISBN: 978-3-527-31913-8

    Ertl, G., Knözinger, H., Schüth, F.,

    Weitkamp, J. (eds.)

    Handbook of HeterogeneousCatalysis8 Volumes

    2008

    ISBN: 978-3-527-31241-2

    Astruc, D. (ed.)

    Nanoparticles and Catalysis

    2008

    ISBN: 978-3-527-31572-7

    Chorkendorff, I., Niemantsverdriet, J. W.

    Concepts of Modern Catalysisand Kinetics2007

    ISBN: 978-3-527-31672-4

    Centi, G., van Santen, R. A. (eds.)

    Catalysis for RenewablesFrom Feedstock to EnergyProduction

    2007

    ISBN: 978-3-527-31788-2

    Sheldon, R. A., Arends, I., Hanefeld, U.

    Green Chemistry andCatalysis

    2007

    ISBN: 978-3-527-30715-9

  • Synthesis of Solid Catalysts

    Edited byKrijn P. de Jong

  • The Editor

    Prof. Dr. Krijn P. de JongInorganic Chemistry and CatalysisUtrecht UniversitySorbonnelaan 163548 CA UtrechtThe Netherlands

    � All books published by Wiley-VCH arecarefully produced. Nevertheless, authors,editors, and publisher do not warrant theinformation contained in these books,including this book, to be free of errors.Readers are advised to keep in mind thatstatements, data, illustrations, proceduraldetails or other items may inadvertently beinaccurate.

    Library of Congress Card No.: applied for

    British Library Cataloguing-in-Publication DataA catalogue record for this book is availablefrom the British Library.

    Bibliographic information published bythe Deutsche NationalbibliothekThe Deutsche Nationalbibliothek lists thispublication in the Deutsche National-bibliografie; detailed bibliographic data areavailable on the Internet athttp://dnb.d-nb.de.

    2009 WILEY-VCH Verlag GmbH & Co.KGaA, Weinheim

    All rights reserved (including those oftranslation into other languages). No part ofthis book may be reproduced in any form – byphotoprinting, microfilm, or any othermeans – nor transmitted or translated into amachine language without written permissionfrom the publishers. Registered names,trademarks, etc. used in this book, even whennot specifically marked as such, are not to beconsidered unprotected by law.

    Cover Design Adam Design, WeinheimTypesetting Laserwords, Chennai, IndiaPrinting betz-druck GmbH, DarmstadtBinding Litges & Dopf GmbH, Heppenheim

    Printed in the Federal Republic of GermanyPrinted on acid-free paper

    ISBN: 978-3-527-32040-0

  • V

    Contents

    Preface XIII

    List of Contributors XV

    Abbreviations XIX

    Part I Basic Principles and Tools

    1 General Aspects 3Krijn P. de Jong

    1.1 Importance of Solid Catalysts 31.2 Development of Solid Catalysts 41.3 Development of Solid Catalyst Synthesis 51.4 About This Book 10

    References 10

    2 Interfacial Chemistry 13Alexis Lycourghiotis

    2.1 Introduction 132.2 Interfacial and Bulk Deposition 142.3 The Surface of the Oxidic Supports: Surface Ionization

    Models 152.3.1 The Charged Surface of the Oxidic Supports 152.3.2 Homogeneous Surface Ionization Models 162.3.3 The Music Model 172.4 The Size and the Structure of the Interface 182.5 The Arrangement of the Ions Inside the Interface

    and the Deposition Modes 202.5.1 Indifferent Ions 202.5.2 Transition-Metal Ionic Species 222.6 Determining the Mode of Interfacial Deposition and the Surface

    Speciation/Structure of the Deposited Precursor Species 232.6.1 Introductory Remarks 23

    Synthesis of Solid Catalysts. Edited by K.P. de Jong 2009 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32040-0

  • VI Contents

    2.6.2 Methodologies Based on Macroscopic Adsorption Data andPotentiometric Titrations as well as on MicroelectrophoreticMobility or Streaming Potential Measurements 23

    2.6.3 Spectroscopic Investigations 252.6.4 Quantum-Mechanical Calculations 262.6.5 Electrochemical (Equilibrium) Modeling 262.7 A Case Study: The Deposition of Co(H2O)62+ Aqua Complex

    on the Titania Surface 272.7.1 Experimental Investigation 272.7.2 Quantum-Mechanical Calculations 282.7.3 Electrochemical (Equilibrium) Modeling 29

    References 30

    3 Electrostatic Adsorption 33John R. Regalbuto

    3.1 Introduction 333.2 Purely Electrostatic Adsorption 373.3 Electrostatic Adsorption with Metal Respeciation 383.4 Electrostatic Adsorption and Ion Exchange 413.5 Electrostatic Adsorption and Deposition-Precipitation 453.6 Electrostatic Adsorption and Surface Reaction 463.7 Electrostatics and Dissolution, Reaction, and Redeposition 473.8 Electrostatics-Based Design 483.8.1 Well-Dispersed Single Metals 493.8.2 Selective Adsorption onto Promoters 513.8.3 Bimetallic Catalysts 543.9 Summary 57

    References 57

    4 Impregnation and Drying 59Eric Marceau, Xavier Carrier, and Michel Che

    4.1 Introduction 594.2 Impregnation 614.2.1 Methods of Impregnation 614.2.2 Physical Models for Impregnation 624.3 Drying 644.4 The Chemistry 674.4.1 Concentrations and pH 674.4.2 Precursor-Support Interactions 694.4.2.1 Adsorption: From Electrostatic Interactions to Grafting 694.4.2.2 The Formation of Mixed Phases 704.4.3 Ligands 714.4.4 Counterions 734.5 Impregnation and Drying of an MoOx/Al2O3 Catalyst 744.5.1 Molybdenum Speciation and Its Consequences 74

  • Contents VII

    4.5.2 Degrees of Freedom: Drying Parameters and Ligands in Solution 764.6 Conclusions 77

    References 78

    5 Sol-Gel Processing 83Miron V. Landau

    5.1 Introduction 835.2 Physicochemical Basis and Principles of Sol-Gel Processing 855.2.1 Activation 865.2.2 Polycondensation 875.2.3 Gelation/Aging/Washing 895.2.4 Gel Drying/Desolvation 905.2.5 Stabilization of Xero- and Aerogels 905.3 Application of Sol-Gel Processing for the Preparation

    of Solid Catalysts 915.3.1 Bulk Catalytic Phase Materials: Xero- and Aerogels 915.3.1.1 Monometallic Catalytic Materials 915.3.1.2 Multimetallic Composite Catalytic Phases 945.3.2 Catalytic Materials and Modifiers Entrapped in Porous Matrices 975.3.2.1 Atoms or Molecular Substances Entrapped by Cocondensation

    at the Colloidization Step 985.3.2.2 Molecular Substances Adsorbed or Entrapped

    at the Gelation Step 1035.4 Summary 106

    References 106

    6 Deposition Precipitation 111Krijn P. de Jong

    6.1 Introduction 1116.2 Theory and Practice 1126.3 Mechanistic Studies 1156.3.1 Kinetics 1156.3.2 Molecular Details 1186.4 Case Studies 1206.4.1 pH Increase 1206.4.2 Reduction Deposition Precipitation 1246.4.3 Ligand Removal 1286.4.4 Miscellaneous Methods 1296.5 Summary, Conclusions, and Outlook 131

    Acknowledgments 131References 132

    7 Coprecipitation 135Martin Lok

    7.1 Introduction 135

  • VIII Contents

    7.2 Basic Principles of Precipitation and Nucleation 1367.3 Raw Materials 1397.4 Precipitation Conditions 1417.5 Process Operation 1417.6 Examples 1457.6.1 High Metal Nickel/Alumina Catalysts 1457.6.2 Single-Step Sulfur-Promoted Nickel/Alumina Catalyst 1467.6.3 Copper/Zinc Methanol Catalysts 1477.6.4 Iron-Based Fischer–Tropsch Catalysts 1487.6.5 Unsupported Metal Sulfide Catalysts for Hydrotreating 1487.7 New Developments in Process Monitoring 148

    Acknowledgments 149References 149

    8 Clusters and Immobilization 153Sophie Hermans

    8.1 Introduction 1538.2 The Surface of Common Supports 1548.3 Clusters in Catalysis 1578.4 Reaction with Unmodified Surface 1608.5 ‘‘Ship-in-a-Bottle’’ Synthesis 1638.6 Tethering 1678.7 Concluding Remarks 168

    References 169

    9 Shaping of Solid Catalysts 173Bettina Kraushaar-Czarnetzki and Steffen Peter Müller

    9.1 Objectives of Catalyst Shaping 1739.2 Fixed-Bed Reactors – Particle Beds 1779.2.1 Pelleting 1779.2.2 Granulation 1799.2.3 Extrusion 1819.2.4 Tailoring of the Pore-Size Distribution 1849.2.5 Fixed-Bed Egg-Shell Catalysts 1869.3 Fixed-Bed Reactors – Monoliths 1879.3.1 Honeycombs 1879.3.1.1 Ceramic Honeycombs 1889.3.1.2 Metallic Honeycombs 1909.3.2 Open-Cell Foams 1929.3.3 Coating of Monoliths 1949.4 Catalysts for Moving-Bed Reactors 1959.5 Catalysts for Fluidized Beds 196

    References 198

  • Contents IX

    10 Space and Time-Resolved Spectroscopy of Catalyst Bodies 201Bert M. Weckhuysen

    10.1 Introduction 20110.2 Space- and Time-Resolved Methods Applied to Catalyst Bodies 20110.2.1 Invasive Methods 20210.2.2 Noninvasive Methods 20510.3 Case Studies 20910.3.1 Keggin-Type Co-Mo Complexes in Catalyst Bodies 20910.3.2 Speciation of Co Complexes in Catalyst Bodies 21210.4 Future Prospects 215

    Acknowledgments 215References 216

    11 High-Throughput Experimentation 217Uwe Rodemerck and David Linke

    11.1 Introduction 21711.2 Synthesis Strategies 21911.2.1 Combinatorial Strategies 22011.2.2 Methods to Reduce Experiments 22011.3 Catalyst Libraries for Primary Screening 22311.3.1 Wafer-Based Preparation 22311.3.2 Single Pellets 22411.3.3 Single Beads 22511.4 Catalyst Libraries for Secondary Screening 22511.4.1 Impregnation Techniques 22611.4.2 Precipitation 22611.4.3 Hydrothermal Synthesis 23011.4.4 Sol-Gel Chemistry 23111.4.5 Drying, Calcination, and Shaping 23111.5 Catalyst Libraries for Special Reactor Types 23411.6 An Industrial Point of View 23411.7 Conclusions 235

    References 236

    Part II Case Studies

    12 Concepts for Preparation of Zeolite-Based Catalysts 243Metin Bulut and Pierre A. Jacobs

    12.1 Introduction and Scope 24312.2 Zeolite Effects in Catalysis 24512.2.1 Brønsted Acidity in Metallosilicate Zeolites 24512.2.2 Zeolite Protonic Superacidity 24612.2.3 Brønsted Acidity in Substituted Four-Coordinated

    Aluminophosphates 24712.2.4 Zeolite Shape Selectivity 250

  • X Contents

    12.2.5 Concentration Effects by Specific Adsorption 25312.2.6 Site Isolation or the Role of Zeolites as Solid Solvents 25412.3 Zeolitization 25412.3.1 Overall Steps in Zeolite Crystallization 25512.3.2 Classic Model for Zeolite Growth 25712.3.3 The Aggregation Model 25912.3.4 Zeolitization Parameters 26012.3.5 Nanocrystalline Zeolites 26412.3.6 Zeolite Synthesis via the Dry Gel Route 26512.3.7 AlPO4-n-Based Molecular Sieve Zeolites 26612.3.8 Ionothermal Synthesis Method 26712.3.9 Zeolites with Pores Beyond the 12-MR 26712.3.10 Upscaling of Zeolite Synthesis 268

    References 268Further Reading 276

    13 Ordered Mesoporous Materials 277Ying Wan and Dongyuan Zhao

    13.1 Introduction 27713.2 Mesoporous Silica 27713.2.1 MCM-41 27913.2.2 SBA-15 28013.2.3 MCM-48 28113.2.4 Pore-Size Control 28213.3 Organic Group Functionalized Mesoporous Silicates 28413.3.1 Organic Groups Anchored to Mesoporous Silicates 28413.3.2 Periodic Mesoporous Organosilicas 28513.3.3 Adsorption and Catalysis 28513.4 Metal-Substituted Mesoporous Silica Molecular Sieves 28713.5 Carbon 28913.5.1 The Hard-Templating Approach 28913.5.2 The Supramolecular-Templating Approach 29013.6 Nonsiliceous Oxides 29313.6.1 The Supramolecular-Templating Approach 29313.6.2 The Hard-Templating Approach 29413.7 Nonoxides 29413.7.1 SiC-Based Materials 29413.7.2 Metal Sulfides 29613.8 Summary and Remarks 296

    Acknowledgments 297References 297

    14 Hydrotreating Catalysts 301Sonja Eijsbouts

    14.1 Introduction 301

  • Contents XI

    14.2 Typical Hydrotreating Catalyst 30214.2.1 Typical Catalyst Composition 30214.2.2 Literature Describing the Preparation of Hydrotreating Catalysts 30214.3 Support Preparation 30314.3.1 Precipitation of γ -Alumina 30314.3.2 Addition of SiO2 30514.3.3 Addition of Other Components (e.g. Zeolites) and Extrusion 30514.3.4 Drying and Calcination of Al2O3 and SiO2-Al2O3 Supports 30714.4 Metal Comixing/Coextrusion and Coprecipitation Routes 30714.4.1 Addition of Metals to the Al2O3 Dough 30714.4.2 Bulk Catalysts 30814.4.3 Drying and Calcination of Catalysts Prepared by

    Comixing/Coextrusion and Coprecipitation Routes 30814.5 Impregnation of Metals 30914.5.1 Typical Additives and Solution Stabilizers 30914.5.2 Pore-Volume Impregnation versus Dipping/Equilibrium

    Impregnation of Compacted Support Particles 31014.5.3 Sequential versus Coimpregnation 31414.5.4 Drying and Calcination 31514.6 Presulfiding as the Last Stage in Hydrotreating

    Catalyst Preparation 31814.6.1 Presulfiding Goals 31814.6.2 Gas-Phase versus Liquid-Phase Presulfiding 31914.6.3 Ex-situ versus In-situ Presulfiding 32014.7 Industrial Process for the Production of the Oxidic Catalyst 32314.7.1 Industrial Equipment 32314.7.2 Health, Safety, and Environmental Issues 32314.8 Summary 324

    References 324

    15 Methanol Catalysts 329S. Schimpf and M. Muhler

    15.1 Binary Cu/ZnO Catalysts 32915.2 Coprecipitation 33115.2.1 Precipitation 33315.2.2 Aging 33415.2.3 Washing 33715.2.4 Drying and Calcination 33715.2.5 Reduction 33915.3 The Role of Alumina in Ternary Catalysts 34115.4 Alternative Preparation Routes 34415.4.1 Alternative Anions 34415.4.2 Chemical Vapor Deposition 34715.4.3 Promising Strategies 34715.5 Conclusions 348

  • XII Contents

    Acknowledgment 348References 349

    16 Case Studies of Nobel-Metal Catalysts 353Stuart Soled

    16.1 Introduction 35316.2 Optimization of Catalyst Preparation 35416.2.1 Electrostatic Interactions and the Use of Zeta Potential

    Measurements 35516.2.2 Noble-Metal Impregnation Example onto a Modified

    Silica-Alumina Support 35616.2.3 A Novel Approach for the Preparation of Dispersed Ru on Silica 35816.2.4 Other Metals that Form Similar Supported Complexes as Ru 36316.2.5 Conclusions 365

    Acknowledgments 366References 366

    17 Gold Catalysts 369Catherine Louis

    17.1 Introduction 36917.2 Preparations Involving Aqueous Solutions 37017.2.1 Impregnation to Incipient Wetness 37017.2.2 Anion Adsorption 37117.2.3 Small Particles from HAuCl4·3H2O 37117.2.4 Deposition-Precipitation with NaOH 37317.2.5 Gold Complex Interaction with Oxide Supports 37517.2.6 Deposition-Precipitation with Urea 37617.2.7 Cation Adsorption 37817.3 Preparations Involving Organometallic Precursors 37917.3.1 Impregnation of Phosphine-Based Gold Complexes 37917.3.2 Impregnation of Other Organogold Complexes 38017.4 Deposition of Gold Nanoparticles 38017.4.1 Deposition of Gold Colloids 38017.4.2 Deposition of Dendrimer-Encapsulated Gold Nanoparticles 38417.5 One-Step Preparations 38417.5.1 Coprecipitation 38517.5.2 Sol-Gel Method 38617.6 Special Methods 38617.6.1 Photochemical Deposition 38617.6.2 Sonochemical Techniques 38717.7 Conclusion 387

    References 388

    Index 393

  • XIII

    Preface

    Solid catalysts are used in modern energy, chemical and environmentalprocesses. Catalyst performance – activity, selectivity and stability – is largelydetermined by their preparation. In this respect, catalyst synthesis may beconsidered as one of the most influential ‘unit operations’ in industry. Thisbook provides an introduction to basic concepts and research tools relevant tocatalyst synthesis followed by a number of case studies. In this way it is anintroduction to the field of catalyst synthesis for students and newcomers aswell as a reference book for experienced scientists and practitioners. I hopethat this book will stimulate the research field of catalyst synthesis and that itwill support research and applications of solid catalysts by facilitating reliableand reproducible synthesis of materials.

    For me it has been a privilege to work with so many colleagues in developingthis book. I thank all of the lead authors as well as their co-authors for workingwith me on this project. It has been rewarding and I hope that we can continueto work together to foster and develop the field of catalyst synthesis.

    I would like to thank Jos van Dillen and John Geus. They taught me as agraduate student at Utrecht University that catalyst synthesis is a research topicin its own right. For many years colleagues at the Shell Research Laboratoriesin Amsterdam provided a stimulating environment to synthesize and use solidcatalysts. More recently at Utrecht University, staff, students and postdoctoralfellows have worked with me in the field of catalyst synthesis. Working withthem has been a pleasure and is acknowledged.

    Utrecht, December 2008Krijn P. de Jong

    Synthesis of Solid Catalysts. Edited by K.P. de Jong 2009 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32040-0

  • XV

    List of Contributors

    Metin BulutKU LeuvenCOK, Dept. M2S23 Kasteelpark Arenberg3001 Leuven (Heverlee)Belgium

    Xavier CarrierLaboratoire de Réactivitéde Surface(UMR 7197 CNRS)UPMC (Université Pierre etMarie Curie)Tour 54-554 Place Jussieu75252 Paris Cedex 05France

    Michel CheLaboratoire de Réactivitéde Surface(UMR 7197 CNRS)UPMC (Université Pierre etMarie Curie)Tour 54-554 Place Jussieu75252 Paris Cedex 05France

    Krijn P. de JongUtrecht UniversityInorganic Chemistryand CatalysisSorbonnelaan 163584 CA UtrechtThe Netherlands

    Sonja EijsboutsAlbemarle Catalysts Company BVResearch Centre Catalysts1022 AB AmsterdamThe Netherlands

    Sophie HermansCatholic University of LouvainDepartement de ChemiePlace Louis Pasteur, 1 bte. 31348 Louvain-la-NeuveBelgium

    Pierre A. JacobsKU LeuvenCOK, Dept. M2S23 Kasteelpark Arenberg3001 Leuven (Heverlee)Belgium

    Synthesis of Solid Catalysts. Edited by K.P. de Jong 2009 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32040-0

  • XVI List of Contributors

    Bettina Kraushaar-CzarnetzkiUniversity of KarlsruheInstitute of Chemical ProcessEngineering CVTKaiserstr. 1276128 KarlsruheGermany

    Miron V. LandauBen-Gurion Univ. of the NegevDept. of Chem. EngineeringBen-Gurion av. 1Beer-Sheva 84105Israel

    Dr. David LinkeLeibniz-Institut für KatalyseAlbert-Einstein-Str. 29a18059 RostockGermany

    Martin LokJohnson Matthey CatalystsBelasis Avenue, BillinghamCleveland, TS23 1LBUK

    Catherine LouisLaboratoire de Réactivitéde Surface(UMR 7197 CNRS)UPMC (Université Pierre etMarie Curie)Tour 54-55Lab. de Reactions de Surfactants4 Place Jussieu75252 Paris Cedex 05France

    Alexis LycourghiotisUniversity of PatrasDepartment of chemistry26500 PatrasGreece

    Eric MarceauLaboratoire de Réactivitéde Surface(UMR 7197 CNRS)UPMC (Université Pierre etMarie Curie)Tour 54-554 Place Jussieu75252 Paris Cedex 05France

    Martin MuhlerRuhr-Universität BochumLS für Technische ChemieUniversitätsstr. 15044780 BochumGermany

    Steffen Peter MüllerUniversity of Karlsruhe (TH)Institute of Chemical ProcessEngineering CVTKaiserstr. 1276128 KarlsruheGermany

    John R. RegalbutoUniversity of IllinoisChemical Engineering810 Souch Clinton StreetChicago, IL 60607USA

    Uwe RodemerckLeibniz-Institut für KatalyseAlbert-Einstein-Str. 29a18059 RostockGermany

    Sabine SchimpfRuhr-Universität BochumLS für Technische ChemieUniversitätsstr. 15044780 BochumGermany

  • List of Contributors XVII

    Stuart SoledExxonMobil Research andEngineering CompanyCorporate Strategic Research1545 Rt. 22 EastAnnandale, NJ 08801USA

    Ying WanShanghai Normal UniversityDepartment of ChemistryGuilin Road 100Shanghai 200234P. R. China

    Bert M. WeckhuysenUtrecht UniversityInorganic Chemistry and CatalysisSorbonnelaan 163584 CA UtrechtThe Netherlands

    Dongyuan ZhaoFudan UniversityLaboratory of Advanced MaterialsDepartment of ChemistryHandan Road 220Shanghai 200233P.R. China

  • XIX

    Abbreviations

    AHM ammonium-hexa-molybdateBM base metalccp cubic close packingCNF carbon nanofiberCNT carbon nanotubeCT charge transferCVD chemical vapor depositionD4R double four-ringD6R double six-ringDFG Deutsche ForschungsgemeinschaftDI dry impregnationDoE design of experimentDP deposition precipitationDTG differential thermal gravimetryEDF equilibrium deposition filtrationEDTA ethylene diamine tetraacetic acidEDX energy-dispersive X-ray spectroscopyEPR electron paramagnetic resonanceEXAFS extended X-ray absorption fine structure spectroscopyFCC fluid catalytic crackingFTIR Fourier transform infraredhcp hexagonal close packingHDMe hydrodemetallationHDN hydrodenitrogenationHDO hydrodeoxygenationHDS hydrodesulfurizationHPA heteropolyacidIA ion adsorptionICI Imperial Chemical Industriesiep isoelectric pointIE ion exchangeIL ionic liquidIR infrared

    Synthesis of Solid Catalysts. Edited by K.P. de Jong 2009 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32040-0

  • XX Abbreviations

    IWI incipient wetness impregnationIZA International Zeolite AssociationMAS-NMR magic-angle sample spinning nuclear magnetic resonanceMMA methyl methacrylateMOF metal organic frameworkMRI magnetic resonance imagingMTBE methyl tert-butylether(M)HC (mild) hydrocrackingNMR nuclear magnetic resonanceNM noble metalNTA nitrilo triacetic acidOHP outer Helmholtz planePc phthalocyaninePMO periodic mesoporous organosilicaPTA platinum tetraamminePZC point of zero chargeQMS quadrupole mass spectroscopyRDP reduction deposition precipitationRFC reactive frontal chromatographyRPA revised physical adsorptionRT room temperatureSAPO SiAlPO4SCR selective catalytic reductionSDA structure-directing agentSEA strong electrostatic adsorptionSRGO straight run gas oilSTY space time yield3D three-dimensionalTEA triethanolamineTEDDI tomographic energy-dispersive diffraction imagingTEM transmission electron microscopeTEOS tetraethylorthosilicateTMA tetramethylammoniumTMB trimethyl benzeneTPA tetrapropylammoniumTPD temperature-programmed desorptionTPR temperature-programmed reduction2D two-dimensionalUSY ultrastable YUV-VIS ultraviolet-visible spectroscopyVOC volatile organic compoundXPS X-ray photoelectron spectroscopyXRD X-ray diffraction

  • PART IBasic Principles and Tools

    Synthesis of Solid Catalysts. Edited by K.P. de Jong 2009 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32040-0

  • 3

    1General AspectsKrijn P. de Jong

    1.1Importance of Solid Catalysts

    Catalysis is essential to modern energy conversion, chemicals manufacture,and environmental technology. From the start, oil refining and bulk chemicalsmanufacture have relied largely on the application of solid catalysts. Inthe meantime, in specialty and fine-chemicals production catalysis is usedfrequently too. According to current estimates about 85% of all chemicalprocesses make use of catalysis, while all molecules in modern transportationfuels have been confronted with one or more solid catalysts.

    Heterogeneous catalysts, or more specifically solid catalysts, dominateindustrial catalysis. Of all industrial catalytic processes, 80% involves the useof solid catalysts with the remaining 20% for homogeneous catalysts (17%)and biocatalysts (3%). The world catalyst sales in 2004 amounted to 15 billionUS$/a, with 12 billion US$/a for solid catalysts. The growth rate foreseen forcatalyst sales amounts to about 5% per year (see Table 1.1) [1]. Although thecatalyst sales comprise a significant market, the economic impact of catalystsis amplified by their use. The products (mainly fuels and chemicals) obtainedby catalysts usage generate a margin that is a multiple of the catalysts costs.Data are scarce but indicative figures have been reported. For zeolite catalysisa paper by Naber and coworkers quotes figures on the costs of zeolites andtheir upgrading in heavy-oil cracking [2]. From their figures one can estimatethe ratio of product margin divided by zeolite costs to be around 100 forfluid catalytic cracking as well as hydrocracking. If all energy and chemicalindustries are involved a ratio of 100–300 has been published [3] and it seemssufficient for the sake of argument that the total gross margin of the ‘‘catalysisindustry’’ amounts to more than 100 times the catalyst sales, that is, more than1500 billion US$/a. The importance of research and manufacture of catalystsrelates to this gross margin of their application.

    Next to the economic importance we mention the environmental impactof catalysis. The amount of energy and raw materials needed for fuels and

    Synthesis of Solid Catalysts. Edited by K.P. de Jong 2009 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 978-3-527-32040-0

  • 4 1 General Aspects

    Table 1.1 World catalyst demand and forecast (billion US$/a) byapplication [1].

    2007 2010 2013 AAGRa

    Refining 4.35 4.98 5.85 5.7Petrochemicals 3.03 3.64 4.34 7.2Polymers 3.24 3.75 4.30 5.4Fine chemicals/other 1.47 1.59 1.70 2.5Environmental 5.51 6.28 6.93 4.3Total 17.6 20.2 23.1 ∼5

    a Average annual growth rate (%).

    chemicals manufacture is much reduced by using catalysts. In fact today, manyproducts could not be obtained without catalysis. Although sulfur removalfrom oil products started as extraction processes, today’s low-sulfur diesel andgasoline could not be produced in an acceptable manner without hydrodesul-furization (HDS) catalysis. Exhaust catalysis has enabled the widespread useof cars, while selective catalytic reduction of nitrogen oxides has removed thebrown plumes from power and chemical plants. In the future, the importanceof catalysis will grow as raw materials for chemicals diversify and alternativeenergy sources and end use come into play. Building blocks in new energychains, such as water electrolysis and fuel cells, also rely on solid catalysts.

    1.2Development of Solid Catalysts

    In Table 1.2 selected solid catalysts are shown together with their main use.Bulk and supported catalysts as well as zeolite-based catalysts are listed. Manyof the examples shown have been known for decades. However, a continuousand spectacular progress over the years is noted for many catalytic processes.We discuss two examples hereafter.

    Based on the development of both catalysts and reactors [4, 5], theFischer–Tropsch synthesis activity and selectivity of cobalt catalyst haveincreased as illustrated in Figure 1.1. The volume-based activity has increasedby a factor of 10 going from 1940 at space time yield (STY) = 10 to 1990 atSTY = 100, and another factor of 3 is expected to lead to STY = 300 by 2010.Most importantly, with increasing activity the catalysts displayed improvedselectivities to higher hydrocarbons.

    The second example, shown in Figure 1.2, involves the increase of theweight-based activity for HDS of NiMo catalysts over the years [6]. For quite along period, say 1975–1995 the increase of activity has been modest, whereasa steep increase is apparent over the last decade. Low costs for HDS catalystshave been the predominating market factor for previous decades, whereaslegislation for low-sulfur diesel has been a major driver lately. Market pull had

  • 1.3 Development of Solid Catalyst Synthesis 5

    Table 1.2 Survey of selected catalysts with their mainapplications.

    Catalyst Applications

    Ni/SiO2 HydrogenationK2O/Al2O3/Fe Ammonia synthesisAg/α-Al2O3 EpoxidationCrOx/SiO2 PolymerizationCoMoS2/γ -Al2O3 HydrotreatingCo/SiO2 Fischer–Tropsch synthesisCu/ZnO/Al2O3 Methanol synthesisZeolite Y composite Catalytic crackingPt/Mordenite Hydroisomerization of light alkanesV2O5/TiO2 NOx abatementPt/C Hydrogenation; fuel cell

    Figure 1.1 Development of cobalt-basedFischer–Tropsch synthesis in terms of bothactivity (STY = space time yield) andselectivity to hydrocarbons of five or more

    C-atoms. Data from 1940 to 2010 with datapoints from left to right at years 1940, 1990,and 2010, respectively.

    quite an impact at all stages and it shows the great flexibility and potential ofcatalyst preparation to respond quickly.

    One could easily put forward many other examples where catalyst preparationhas been the basis for new and improved processes, such as methanolsynthesis, ethene epoxidation, and acrylic acid production. However, for thetopic of this book it is more important to discuss in which ways catalystpreparation has allowed these new developments.

    1.3Development of Solid Catalyst Synthesis

    Depending on the application, macroscopic catalyst bodies differ in sizeand shape. For slurry and fluid-bed applications the size is in the range of

  • 6 1 General Aspects

    Figure 1.2 Development of hydrodesulfurization (HDS) catalyst activity over the years [6].

    Figure 1.3 Structure at different length scales of catalyst extrudate.

    tens of micrometers, whereas fixed-bed applications require millimeter-sizedparticles. Next to particles, monoliths are used with macroscopic sizes wellbeyond that of particles (Chapter 9). A typical structure for a cylindricallyshaped catalyst body for fixed-bed application is shown in Figure 1.3. Thisfigure also reveals the multiple length scales involved in solid catalysts. Themicroscopic scale involves the structure of the active sites, the mesoscopicscale the pore system and the sizes of support particles as well as the particlesof the active phase. The macroscopic length scale involves the size and shapeof the catalyst bodies. The importance of the microscopic scale goes withoutsaying as it determines the intrinsic activity and selectivity of the catalyst.The mesoscopic length scale affects, amongst others, the intraparticle masstransfer of the catalysts. The macroscopic size and shape is relevant forproperties such as pressure drop (fixed-bed reactor), mechanical strength, andattrition resistance.

    In catalyst manufacturing a final catalyst is usually obtained in multiplesteps. Building blocks of the final catalyst may be obtained from sol-gel type processes with support materials such as alumina and silica asprime examples. Also, zeolites and carbon are relevant catalyst building

  • 1.3 Development of Solid Catalyst Synthesis 7

    Table 1.3 Generations of solid catalysts according to manufacturing techniques.

    Period Material type Key productionstep

    Example – materialand process

    ∼1890 Natural Shaping Bauxite; Claus process∼1930 Natural Shaping Clays; catalytic cracking∼1940 Synthetic Impregnation Pt/Al2O3; reforming∼1970 Synthetic Precipitation Cu/ZnO/Al2O3; methanol

    synthesis∼1980 Synthetic Hydrothermal ZSM-5;

    methanol-to-gasoline>2000 Nanostructured Templating,

    CVDMCM-41, SBA-15, CNF,CNT

    See main text for an explanation of abbreviations.

    blocks. The synthesis of these ‘‘building blocks’’ mostly leads to primaryparticles in the nanometer or micrometer range that have to be shaped tomacroscopic sizes (Chapter 9). Subsequently, shaped particles can be loadedwith active components via methods such as impregnation and drying or ionadsorption.

    The development of the manufacture of solid catalyst synthesis issummarized in Table 1.3. The first solid catalysts comprised of supportsand active phase available from nature. Bauxite and clays are examplesof active phases, while ‘‘diatomaceous earth’’ or ‘‘kieselguhr’’ is a naturalsource of silica support material. Using sol-gel chemistry synthetic supportmaterials have been developed. Application techniques for the active phasebased on impregnation and drying emerged during the twentieth century.Hydrothermal synthesis has been important for synthetic zeolites such asZSM-5. Using micelle templating nanostructured silica (MCM-41, SBA-15)and other oxides have been produced during the last two decades. Usingchemical vapor deposition (CVD) techniques nanostructured carbon materialssuch as carbon nanofibers (CNFs) and carbon nanotubes (CNTs) have beenproduced and explored as catalyst supports [7].

    Figure 1.4 displays three generations of support materials, that is, nat-ural silica (kieselguhr), silica gel and ordered mesoporous silica. Movingfrom natural (Figure 1.4a) to synthetic (Figure 1.4b) materials has greatlyimproved the control over composition and texture of the support inquestion. Although diatomaceous earth has been named ‘‘nature’s nanotech-nology’’, one should realize that, next to a low specific surface area andbroad pore-size distribution, the variation in properties is a major issue.The latest advancement of synthetic nanostructured supports (Figure 1.4c)has not yet resulted in many new industrial catalysts. For fundamen-tal studies on catalyst preparation, however, these materials are of greatvalue with results that can be translated to more conventional supportmaterials [8].

  • 8 1 General Aspects

    Figure 1.4 Silica materials that have been used catalyst support.(a) Natural silica, kieselguhr (∼20 m2 g−1); (b) silica gel(∼500 m2 g−1); and (c) ordered mesoporous silica, SBA-15(∼500 m2 g−1).

    Here, we illustrate the impact of new supports, on the one hand, and newcatalyst synthesis methods, on the other hand, by considering the showcaseof the preparation of silica-supported cobalt catalysts for Fischer–Tropschsynthesis. In Figure 1.5 different generations of cobalt catalysts are shown.In Figure 1.5a a kieselguhr-supported cobalt catalyst is shown that has beenprepared according to a recipe from the 1940s reported by Anderson [9] thatinvolves precipitation in the presence of the support. The large amount ofcobalt separate from the support is apparent as well as clustering of the cobaltparticles. Using a synthetic silica gel and impregnation with aqueous cobalt


Recommended