Preface ................................................... XIII
List of Contributors ........................................ XV
Abbreviations .............................................. XIX
Part I Basic Principles and Tools
1 General Aspects .............................................. 3
Krijn P. de Jong
1.1 Importance of Solid Catalysts ........................... 3
1.2 Development of Solid Catalysts .......................... 4
1.3 Development of Solid Catalyst Synthesis ................. 5
1.4 About This Book ........................................ 10
References .................................................. 10
2 Interfacial Chemistry ....................................... 13
Alexis Lycourghiotis
2.1 Introduction ........................................... 13
2.2 Interfacial and Bulk Deposition ........................ 14
2.3 The Surface of the Oxidic Supports: Surface
Ionization Models ...................................... 15
2.3.1 The Charged Surface of the Oxidic Supports ...... 15
2.3.2 Homogeneous Surface Ionization Models ........... 26
2.3.3 The Music Model ................................. 17
2.4 The Size and the Structure of the Interface ............ 18
2.5 The Arrangement of the Ions Inside the Interface and
the Deposition Modes ................................... 20
2.5.1 Indifferent Ions ................................ 20
2.5.2 Transition-Metal Ionic Species .................. 22
2.6 Determining the Mode of Interfacial Deposition and
the Surface Speciation/ Structure of the Deposited
Precursor Species ...................................... 23
2.6.1 Introductory Remarks ............................ 23
2.6.2 Methodologies Based on Macroscopic Adsorption
Data and Potentiometric Titrations as well as
on Microelectrophoretic Mobility or Streaming
Potential Measurements .......................... 23
2.6.3 Spectroscopic Investigations .................... 25
2.6.4 Quantum-Mechanical Calculations ................. 26
2.6.5 Electrochemical (Equilibrium) Modeling .......... 26
2.7 A Case Study: The Deposition of Со(Н2О)62+ Aqua
Complex on the Titania Surface ......................... 27
2.7.1 Experimental Investigation ...................... 27
2.7.2 Quantum-Mechanical Calculations ................. 28
2.7.3 Electrochemical (Equilibrium) Modeling .......... 29
References .................................................. 30
3 Electrostatic Adsorption .................................... 33
John R. Regalbuto
3.1 Introduction ........................................... 33
3.2 Purely Electrostatic Adsorption ........................ 37
3.3 Electrostatic Adsorption with Metal Respeciation ....... 38
3.4 Electrostatic Adsorption and Ion Exchange .............. 41
3.5 Electrostatic Adsorption and Deposition-
Precipitation .......................................... 45
3.6 Electrostatic Adsorption and Surface Reaction .......... 46
3.7 Electrostatics and Dissolution, Reaction, and
Redeposition
3.8 Electrostatics-Based Design ............................ 48
3.8.1 Well-Dispersed Single Metals .................... 49
3.8.2 Selective Adsorption onto Promoters ............. 51
3.8.3 Bimetallic Catalysts ............................ 54
3.9 Summary ................................................ 57
References .................................................. 57
4 Impregnation and Drying ..................................... 59
Eric Marceau, Xavier Carrier, and Michel Che
4.1 Introduction ........................................... 59
4.2 Impregnation ........................................... 61
4.2.1 Methods of Impregnation ......................... 61
4.2.2 Physical Models for Impregnation ................ 62
4.3 Drying ................................................. 64
4.4 The Chemistry .......................................... 67
4.4.1 Concentrations and pH ........................... 67
4.4.2 Precursor-Support Interactions .................. 69
4.4.2.1 Adsorption: From Electrostatic
Interactions to Grafting ............... 69
4.4.2.2 The Formation of Mixed Phases .......... 70
4.4.3 Ligands ......................................... 71
4.4.4 Counterions ..................................... 73
4.5 Impregnation and Drying of an MoOx/Al2O3 Catalyst ...... 74
4.5.1 Molybdenum Speciation and Its Consequences ...... 74
4.5.2 Degrees of Freedom: Drying Parameters and
Ligands in Solution ............................. 76
4.6 Conclusions ............................................ 77
References .................................................. 78
5 Sol-Gel Processing .......................................... 83
Miron V. Landau
5.1 Introduction ........................................... 83
5.2 Physicochemical Basis and Principles of Sol-Gel
Processing ............................................. 85
5.2.1 Activation ...................................... 86
5.2.2 Polycondensation ................................ 87
5.2.3 Gelation/Aging/Washing .......................... 89
5.2.4 Gel Drying/Desolvation .......................... 90
5.2.5 Stabilization of Xero-and Aerogels .............. 90
5.3 Application of Sol-Gel Processing for the Preparation
of Solid Catalysts ..................................... 91
5.3.1 Bulk Catalytic Phase Materials: Xero-and
Aerogels ........................................ 91
5.3.1.1 Monometallic Catalytic Materials ....... 91
5.3.1.2 Multimetallic Composite Catalytic
Phases ................................. 94
5.3.2 Catalytic Materials and Modifiers Entrapped in
Porous Matrices ...................................... 97
5.3.2.1 Atoms or Molecular Substances Entrapped by
Cocondensation at the Colloidization Step ... 98
5.3.2.2 Molecular Substances Adsorbed or
Entrapped at the Gelation Step ............. 103
5.4 Summary ............................................... 106
References ................................................. 106
6 Deposition Precipitation ................................... 111
Krijn P. de Jong
6.1 Introduction .......................................... 111
6.2 Theory and Practice ................................... 112
6.3 Mechanistic Studies ................................... 115
6.3.1 Kinetics ....................................... 115
6.3.2 Molecular Details .............................. 118
6.4 Case Studies .......................................... 120
6.4.1 pH Increase .................................... 120
6.4.2 Reduction Deposition Precipitation ............. 124
6.4.3 Ligand Removal ................................. 128
6.4.4 Miscellaneous Methods .......................... 129
6.5 Summary, Conclusions, and Outlook ..................... 131
Acknowledgments ............................................ 131
References ................................................. 132
7 Coprecipitation ............................................ 135
Martin Lok
7.1 Introduction .......................................... 135
7.2 Basic Principles of Precipitation and Nucleation ...... 136
7.3 Raw Materials ......................................... 139
7.4 Precipitation Conditions .............................. 141
7.5 Process Operation ..................................... 141
7.6 Examples .............................................. 145
7.6.1 High Metal Nickel/Alumina Catalysts ............ 145
7.6.2 Single-Step Sulfur-Promoted Nickel/Alumina
Catalyst ....................................... 146
7.6.3 Copper/Zinc Methanol Catalysts ................. 147
7.6.4 Iron-Based Fischer-Tropsch Catalysts ........... 148
7.6.5 Unsupported Metal Sulfide Catalysts for
Hydrotreating .................................. 148
7.7 New Developments in Process Monitoring ................ 148
Acknowledgments ............................................ 149
References ................................................. 149
8 Clusters and Immobilization ................................ 153
Sophie Hermans
8.1 Introduction .......................................... 153
8.2 The Surface of Common Supports ........................ 154
8.3 Clusters in Catalysis ................................. 157
8.4 Reaction with Unmodified Surface ...................... 160
8.5 "Ship-in-a-Bottle" Synthesis .......................... 163
8.6 Tethering ............................................. 167
8.7 Concluding Remarks .................................... 168
References ................................................. 169
9 Shaping of Solid Catalysts ................................. 173
Bettina Kraushaar-Czarnetzki and Steffen Peter Müller
9.1 Objectives of Catalyst Shaping ........................ 173
9.2 Fixed-Bed Reactors - Particle Beds .................... 177
9.2.1 Pelleting ...................................... 177
9.2.2 Granulation .................................... 179
9.2.3 Extrusion ...................................... 181
9.2.4 Tailoring of the Pore-Size Distribution ........ 184
9.2.5 Fixed-Bed Egg-Shell Catalysts .................. 186
9.3 Fixed-Bed Reactors - Monoliths ........................ 187
9.3.1 Honeycombs ..................................... 187
9.3.1.1 Ceramic Honeycombs .................... 188
9.3.1.2 Metallic Honeycombs ................... 190
9.3.2 Open-Cell Foams ................................ 192
9.3.3 Coating of Monoliths ........................... 194
9.4 Catalysts for Moving-Bed Reactors ..................... 195
9.5 Catalysts for Fluidized Beds .......................... 196
References ................................................. 198
10 Space and Time-Resolved Spectroscopy of Catalyst Bodies .... 201
Bert M. Weckhuysen
10.1 Introduction .......................................... 201
10.2 Space- and Time-Resolved Methods Applied to Catalyst
Bodies ................................................ 201
10.2.1 Invasive Methods ............................... 202
10.2.2 Noninvasive Methods ........................... 205
10.3 Case Studies .......................................... 209
10.3.1 Keggin-Type Co-Mo Complexes in Catalyst
Bodies ......................................... 209
10.3.2 Speciation of Co Complexes in Catalyst
Bodies ......................................... 212
10.4 Future Prospects ...................................... 215
Acknowledgments ............................................ 215
References ................................................. 216
11 High-Throughput Experimentation ............................ 217
Uwe Rodemerck and David Linke
11.1 Introduction .......................................... 217
11.2 Synthesis Strategies .................................. 219
11.2.1 Combinatorial Strategies ....................... 220
11.2.2 Methods to Reduce Experiments .................. 220
11.3 Catalyst Libraries for Primary Screening .............. 223
11.3.1 Wafer-Based Preparation ........................ 223
11.3.2 Single Pellets ................................. 224
11.3.3 Single Beads ................................... 225
11.4 Catalyst Libraries for Secondary Screening ............ 225
11.4.1 Impregnation Techniques ........................ 226
11.4.2 Precipitation .................................. 226
11.4.3 Hydrothermal Synthesis ......................... 230
11.4.4 Sol-Gel Chemistry .............................. 231
11.4.5 Drying, Calcination, and Shaping ............... 231
11.5 Catalyst Libraries for Special Reactor Types .......... 234
11.6 An Industrial Point of View ........................... 234
11.7 Conclusions ........................................... 235
References ................................................. 236
Part II Case Studies
12 Concepts for Preparation of Zeolite-Based Catalysts ........ 243
Metin Bulut and Pierre A. Jacobs
12.1 Introduction and Scope ................................ 243
12.2 Zeolite Effects in Catalysis .......................... 245
12.2.1 Brønsted Acidity in Metallosilicate Zeolites ... 245
12.2.2 Zeolite Protonic Superacidity .................. 246
12.2.3 Brønsted Acidity in Substituted Four-
Coordinated Aluminophosphates .................. 247
12.2.4 Zeolite Shape Selectivity ...................... 250
12.2.5 Concentration Effects by Specific Adsorption ... 253
12.2.6 Site Isolation or the Role of Zeolites as
Solid Solvents ................................. 254
12.3 Zeolitization ......................................... 254
12.3.1 Overall Steps in Zeolite Crystallization ....... 255
12.3.2 Classic Model for Zeolite Growth ............... 257
12.3.3 The Aggregation Model .......................... 259
12.3.4 Zeolitization Parameters ....................... 260
12.3.5 Nanocrystalline Zeolites ....................... 264
12.3.6 Zeolite Synthesis via the Dry Gel Route ........ 265
12.3.7 AlPO4-n-Based Molecular Sieve Zeolites ......... 266
12.3.8 Ionothermal Synthesis Method ................... 267
12.3.9 Zeolites with Pores Beyond the 12-MR ........... 267
12.3.10 Upscaling of Zeolite Synthesis ................ 268
References ................................................. 268
Further Reading ............................................ 276
13 Ordered Mesoporous Materials ............................... 277
Ying Wan and Dongyuan Zhao
13.1 Introduction .......................................... 277
13.2 Mesoporous Silica ..................................... 277
13.2.1 MCM-41 ......................................... 279
13.2.2 SBA-15 ......................................... 280
13.2.3 MCM-48 ......................................... 281
13.2.4 Pore-Size Control .............................. 282
13.3 Organic Group Functionalized Mesoporous Silicates ..... 284
13.3.1 Organic Groups Anchored to Mesoporous
Silicates ...................................... 284
13.3.2 Periodic Mesoporous Organosilicas .............. 285
13.3.3 Adsorption and Catalysis ....................... 285
13.4 Metal-Substituted Mesoporous Silica Molecular
Sieves ................................................ 287
13.5 Carbon ................................................ 289
13.5.1 The Hard-Templating Approach ................... 289
13.5.2 The Supramolecular-Templating Approach ......... 290
13.6 Nonsiliceous Oxides ................................... 293
13.6.1 The Supramolecular-Templating Approach ......... 293
13.6.2 The Hard-Templating Approach ................... 294
13.7 Nonoxides ............................................. 294
13.7.1 SiC-Based Materials ............................ 294
13.7.2 Metal Sulfides ................................. 296
13.8 Summary and Remarks ................................... 296
Acknowledgments ............................................ 297
References ................................................. 297
14 Hydrotreating Catalysts .................................... 301
Sonja Eijsbouts
14.1 Introduction .......................................... 301
14.2 Typical Hydrotreating Catalyst ........................ 302
14.2.1 Typical Catalyst Composition ................... 302
14.2.2 Literature Describing the Preparation of
Hydrotreating Catalysts ........................ 302
14.3 Support Preparation ................................... 303
14.3.1 Precipitation of γ-Alumina ..................... 303
14.3.2 Addition of SiO2 ............................... 305
14.3.3 Addition of Other Components (e.g. Zeolites)
and Extrusion .................................. 305
14.3.4 Drying and Calcination of Аl2O3 and SiO2-Al2O3
Supports ....................................... 307
14.4 Metal Comixing/Coextrusion and Coprecipitation
Routes ................................................ 307
14.4.1 Addition of Metals to the Al2O3 Dough .......... 307
14.4.2 Bulk Catalysts ................................. 308
14.4.3 Drying and Calcination of Catalysts Prepared
by Comixing/Coextrusion and Coprecipitation
Routes ......................................... 308
14.5 Impregnation of Metals ................................ 309
14.5.1 Typical Additives and Solution Stabilizers ..... 309
14.5.2 Pore-Volume Impregnation versus Dipping/
Equilibrium Impregnation of Compacted Support
Particles ...................................... 310
14.5.3 Sequential versus Coimpregnation ............... 314
14.5.4 Drying and Calcination ......................... 315
14.6 Presulfiding as the Last Stage in Hydrotreating
Catalyst Preparation .................................. 318
14.6.1 Presulfiding Goals ............................. 318
14.6.2 Gas-Phase versus Liquid-Phase Presulfiding ..... 319
14.6.3 Ex-situ versus In-situ Presulfiding ............ 320
14.7 Industrial Process for the Production of the Oxidic
Catalyst .............................................. 323
14.7.1 Industrial Equipment ........................... 323
14.7.2 Health, Safety, and Environmental Issues ....... 323
14.8 Summary ............................................... 324
References ................................................. 324
15 Methanol Catalysts ......................................... 329
S. Schimpf and M. Muhler
15.1 Binary Cu/ZnO Catalysts ............................... 329
15.2 Coprecipitation ....................................... 331
15.2.1 Precipitation .................................. 333
15.2.2 Aging .......................................... 334
15.2.3 Washing ........................................ 337
15.2.4 Drying and Calcination ......................... 337
15.2.5 Reduction ...................................... 339
15.3 The Role of Alumina in Ternary Catalysts .............. 341
15.4 Alternative Preparation Routes ........................ 344
15.4.1 Alternative Anions ............................. 344
15.4.2 Chemical Vapor Deposition ...................... 347
15.4.3 Promising Strategies ........................... 347
15.5 Conclusions ........................................... 348
Acknowledgment ............................................. 348
References ................................................. 349
16 Case Studies of Nobel-Metal Catalysts ...................... 353
Stuart Soled
16.1 Introduction .......................................... 353
16.2 Optimization of Catalyst Preparation .................. 354
16.2.1 Electrostatic Interactions and the Use of
Zeta Potential Measurements .................... 355
16.2.2 Noble-Metal Impregnation Example onto a
Modified Silica-Alumina Support ................ 356
16.2.3 A Novel Approach for the Preparation of
Dispersed Ru on Silica ......................... 358
16.2.4 Other Metals that Form Similar Supported
Complexes as Ru ................................ 363
16.2.5 Conclusions .................................... 365
Acknowledgments ............................................ 366
References ................................................. 366
17 Cold Catalysts ............................................. 369
Catherine Louis
17.1 Introduction .......................................... 369
17.2 Preparations Involving Aqueous Solutions .............. 370
17.2.1 Impregnation to Incipient Wetness .............. 370
17.2.2 Anion Adsorption ............................... 371
17.2.3 Small Particles from HAuCl4-3H20 ............... 371
17.2.4 Deposition-Precipitation with NaOH ............. 373
17.2.5 Gold Complex Interaction with Oxide Supports ... 375
17.2.6 Deposition-Precipitation with Urea ............. 376
17.2.7 Cation Adsorption .............................. 378
17.3 Preparations Involving Organometallic Precursors ...... 379
17.3.1 Impregnation of Phosphine-Based Gold
Complexes ...................................... 379
17.3.2 Impregnation of Other Organogold Complexes ..... 380
17.4 Deposition of Gold Nanoparticles ...................... 380
17.4.1 Deposition of Gold Colloids .................... 380
17.4.2 Deposition of Dendrimer-Encapsulated Gold
Nanoparticles .................................. 384
17.5 One-Step Preparations ................................. 384
17.5.1 Coprecipitation ................................ 385
17.5.2 Sol-Gel Method ................................. 386
17.6 Special Methods ....................................... 386
17.6.1 Photochemical Deposition ....................... 386
17.6.2 Sonochemical Techniques ........................ 387
17.7 Conclusion ............................................ 387
References ................................................. 388
Index ...................................................... 393
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