Catalysis

Preface xi 1 Introduction 1 1.1 Green Chemistry and Sustainable Development 1 1.1.1 What Is ‘Green Chemistry’? 2 1.1.2 Quantifying Environmental Impact: Efficiency, E-Factors, and Atom Economy 4 1.1.3 Just How ‘Green’ Is This Process? 6 1.1.4 Product and Process Life-Cycle Assessment (LCA) 10 1.2 What Is Catalysis and Why Is It Important? 12 1.2.1 Homogeneous Catalysis, Heterogeneous Catalysis, and Biocatalysis: Definitions and Examples 14 1.2.2 Connecting Catalysis and Sustainability: Saving Resources by Using Catalytic Cycles 20 1.2.3 Industrial Example: the BHC Ibuprofen Process 22 1.3 Tools in Catalysis Research 24 1.3.1 Catalyst Synthesis and Testing Tools 24 1.3.2 Catalyst Characterisation Tools 27 1.3.3 Modelling/Mechanistic Studies Tools 28 1.4 Exercises 30 References 38 Further Reading 41 2 The Basics of Catalysis 43 2.1 Catalysis Is a Kinetic Phenomenon 43 2.1.1 Reaction Rates, Reaction Orders, Rate Equations and Rate-Determining Steps 45 2.1.2 The Reaction Profile and the Reaction Coordinate 49 2.1.3 Zero-Order, First-Order and Second-Order Kinetics 52 2.1.4 Langmuir–Hinshelwood Kinetics 58 2.1.5 The Steady-State Approximation 61 2.1.6 Michaelis–Menten Kinetics 62 2.1.7 Consecutive and Parallel First-Order Reactions 66 2.1.8 Pre-equilibrium, ‘Catalyst Reservoirs’, and Catalyst Precursors 67 2.2 Practical Approaches in Kinetic Studies 70 2.2.1 Initial Reaction Rates and Concentration Effects 70 2.2.2 Creating Pseudo-Order Conditions 71 2.2.3 What You See vs. What You Get 72 2.2.4 Learning from Stoichiometric Experiments 73 2.3 An Overview of Some Basic Concepts in Catalysis 74 2.3.1 Catalyst-Substrate Interactions and Sabatier’s Principle 74 2.3.2 Catalyst Deactivation, Sintering, and Thermal Degradation 75 2.3.3 Catalyst Inhibition 78 2.4 Exercises 79 References 85 3 Homogeneous Catalysis 89 3.1 Metal Complex Catalysis in the Liquid Phase 90 3.1.1 Elementary Steps in Homogeneous Catalysis 91 3.1.2 Structure-Activity Relationships in Homogeneous Catalysis 100 3.1.3 Asymmetric Homogeneous Catalysis 106 3.1.4 Industrial Examples 109 3.2 Homogeneous Catalysis without Metals 117 3.2.1 Classic Acid/Base Catalysis 117 3.2.2 Organocatalysis 117 3.3 Scaling Up Homogeneous Reactions: Pros and Cons 119 3.3.1 Catalyst Recovery and Recycling 120 3.3.2 Immobilised Complexes and Ship-In-A-Bottle Catalysts 122 3.4 ‘Click Chemistry’ and Homogeneous Catalysis 122 3.5 Exercises 124 References 131 4 Heterogeneous Catalysis 137 4.1 Classic Gas/Solid Systems 139 4.1.1 The Concept of the Active Site 141 4.1.2 Model Catalyst Systems 143 4.1.3 Real Catalysts: Promoters, Modifiers, and Poisons 144 4.1.4 Preparation of Solid Catalysts: Black Magic Revealed 146 4.1.5 Selecting the Right Support 154 4.1.6 Catalyst Characterisation 157 4.1.7 The Catalytic Converter: an Example from Everyday Life 166 4.1.8 Surface Organometallic Chemistry 168 4.2 Liquid/Solid and Liquid/Liquid Catalytic Systems 171 4.2.1 Aqueous Biphasic Catalysis 171 4.2.2 Fluorous Biphasic Catalysis 173 4.2.3 Biphasic Catalysis Using Ionic Liquids 175 4.2.4 Phase-Transfer Catalysis 176 4.3 Advanced Process Solutions Using Heterogeneous Catalysis 178 4.3.1 The BP AVADA Ethyl Acetate Process 178 4.3.2 The CB&I Lummus/Albemarle AlkyClean Process 179 4.3.3 The IFP and Yellowdiesel Processes for Biodiesel Production 180 4.3.4 The ABB Lummus/UOP SMART Process 184 4.4 Exercises 186 References 196 5 Biocatalysis 205 5.1 The Basics of Enzymatic Catalysis 206 5.1.1 Terms and Definitions – the Bio Dialect 206 5.1.2 Active Sites and Substrate Binding Models 210 5.1.3 Intramolecular Reactions and Proximity Effects 212 5.1.4 Common Mechanisms in Enzymatic Catalysis 213 5.2 Applications of Enzyme Catalysis 215 5.2.1 Whole-Cell Systems vs. Isolated Enzymes 216 5.2.2 Immobilised Enzymes: Bona Fide Heterogeneous Catalysis 218 5.2.3 Replacing ‘Conventional Routes’ with Biocatalysis 221 5.2.4 Combining ‘Bio’ and ‘Chemo’ Catalysis 223 5.3 Developing New Biocatalysts: Better than Nature’s Best 225 5.3.1 Prospecting Natural Diversity 226 5.3.2 Rational Design 226 5.3.3 Directed Evolution 227 5.4 Non-enzymatic Biocatalysts 229 5.4.1 Catalytic Antibodies (Abzymes) 229 5.4.2 Catalytic RNA (Ribozymes) 230 5.5 Industrial Examples 232 5.5.1 High-Fructose Corn Syrup: 11 Million Tons per Year 232 5.5.2 The Mitsubishi Rayon Acrylamide Process 233 5.5.3 The BMS Paclitaxel Process 235 5.5.4 The Tosoh/DSM Aspartame Process 236 5.6 Exercises 237 References 243 6 Computer Applications in Catalysis Research 249 6.1 Computers as Research Tools in Catalysis 249 6.2 Modelling of Catalysts and Catalytic Cycles 251 6.2.1 A Short Overview of Modelling Methods 251 6.2.2 Simplified Model Systems vs. Real Reactions 253 6.2.3 Modelling Large Catalyst Systems Using Classical Mechanics 254 6.2.4 In-Depth Reaction Modelling Using Quantum Mechanics 256 6.3 Predictive Modelling and Rational Catalyst Design 258 6.3.1 Catalysts, Descriptors, and Figures of Merit 259 6.3.2 Three-Dimensional (3D) Descriptors of Homogeneous Catalysts 260 6.3.3 Two-Dimensional (2D) Descriptors of Homogeneous Catalysts 263 6.3.4 Descriptors of Heterogeneous (Solid) Catalysts 267 6.3.5 Predictive Modelling in Biocatalysis 271 6.3.6 Generating Virtual Catalyst Libraries in Space A 272 6.3.7 Understanding Catalyst Diversity 273 6.3.8 Virtual catalyst Screening: connecting Spaces A, B, and c 276 6.4 An Overview of Data Mining Methods in Catalysis 277 6.4.1 Principal Components Analysis (PCA) 279 6.4.2 Partial Least-Squares (PLS) Regression 281 6.4.3 Artificial Neural Networks (ANNs) 283 6.4.4 Classification Trees 284 6.4.5 Model Validation: Separating Knowledge from Garbage 284 6.5 Exercises 287 References 291 Index 297