Preface XI
List of Contributors XV
1 Modeling Catalytic Reactions on Surfaces with Density Functional Theory 1
John A. Keith, Josef Anton, Payam Kaghazchi, and Timo Jacob
1.1 Introduction 1
1.2 Theoretical Background 2
1.2.1 The Many-Body Problem 2
1.2.2 Born–Oppenheimer Approximation 3
1.2.3 Wave Function-Based Methods 4
1.2.3.1 Hartree–Fock Approximation 4
1.2.3.2 Post Hartree–Fock Methods 5
1.2.4 Density-Based Methods 6
1.2.4.1 The Thomas–Fermi Model 7
1.2.4.2 The Hohenberg–Kohn Theorems 7
1.2.4.3 The Kohn–Sham Equations 9
1.2.4.4 Exchange–Correlation Functionals 10
1.2.5 Technical Aspects of Modeling Catalytic Reactions 13
1.2.5.1 Geometry Optimizations 13
1.2.5.2 Transition-State Optimizations 14
1.2.5.3 Vibrational Frequencies 14
1.2.5.4 Thermodynamic Treatments of Molecules 16
1.2.5.5 Considering Solvation 17
1.2.6 Model Representation 19
1.2.6.1 Slab/Supercell Approach 19
1.2.6.2 Cluster Approach 21
1.3 The Electrocatalytic Oxygen Reduction Reaction on Pt(111) 22
1.3.1 Water Formation from Gaseous O2 and H2 24
1.3.1.1 O2 Dissociation 25
1.3.1.2 OOH Formation 27
1.3.1.3 HOOH Formation 28
1.3.2 Simulations Including Water Solvation 28
1.3.2.1 Langmuir–Hinshelwood Mechanisms 30
1.3.2.2 Eley–Rideal Reactions 31
1.3.3 Including Thermodynamical Quantities 32
1.3.3.1 Langmuir–Hinshelwood and Eley–Rideal Mechanisms 33
1.3.4 Including an Electrode Potential 35
1.4 Conclusions 36
References 37
2 Dynamics of Reactions at Surfaces 39
Axel Groß
2.1 Introduction 39
2.2 Theoretical and Computational Foundations of Dynamical Simulations 41
2.3 Interpolation of Potential Energy Surfaces 43
2.4 Quantum Dynamics of Reactions at Surfaces 45
2.5 Nondissociative Molecular Adsorption Dynamics 49
2.6 Adsorption Dynamics on Precovered Surfaces 55
2.7 Relaxation Dynamics of Dissociated H2 Molecules 59
2.8 Electronically Nonadiabatic Reaction Dynamics 62
2.9 Conclusions 66
References 67
3 First-Principles Kinetic Monte Carlo Simulations for Heterogeneous Catalysis: Concepts, Status, and Frontiers 71
Karsten Reuter
3.1 Introduction 71
3.2 Concepts and Methodology 73
3.2.1 The Problem of a Rare Event Dynamics 73
3.2.2 State-to-State Dynamics and kMC Trajectories 75
3.2.3 kMC Algorithms: from Basics to Efficiency 77
3.2.4 Transition State Theory 80
3.2.5 First-Principles Rate Constants and the Lattice Approximation 84
3.3 A Showcase 88
3.3.1 Setting up the Model: Lattice, Energetics, and Rate Constant Catalog 88
3.3.2 Steady-State Surface Structure and Composition 90
3.3.3 Parameter-Free Turnover Frequencies 95
3.3.4 Temperature-Programmed Reaction Spectroscopy 99
3.4 Frontiers 102
3.5 Conclusions 107
References 108
4 Modeling the Rate of Heterogeneous Reactions 113
Lothar Kunz, Lubow Maier, Steffen Tischer, and Olaf Deutschmann
4.1 Introduction 113
4.2 Modeling the Rates of Chemical Reactions in the Gas Phase 115
4.3 Computation of Surface Reaction Rates on a Molecular Basis 116
4.3.1 Kinetic Monte Carlo Simulations 116
4.3.2 Extension of MC Simulations to Nanoparticles 120
4.3.3 Reaction Rates Derived from MC Simulations 124
4.3.4 Particle–Support Interaction and Spillover 125
4.3.5 Potentials and Limitations of MC Simulations for Derivation of Overall Reaction Rates 125
4.4 Models Applicable for Numerical Simulation of Technical Catalytic Reactors 128
4.4.1 Mean Field Approximation and Reaction Kinetics 129
4.4.2 Thermodynamic Consistency 131
4.4.3 Practicable Method for Development of Multistep Surface Reaction Mechanisms 134
4.4.4 Potentials and Limitations of the Mean Field Approximation 139
4.5 Simplifying Complex Kinetic Schemes 141
4.6 Summary and Outlook 142
References 143
5 Modeling Reactions in Porous Media 149
Frerich J. Keil
5.1 Introduction 149
5.2 Modeling Porous Structures and Surface Roughness 152
5.3 Diffusion 158
5.4 Diffusion and Reaction 163
5.5 Pore Structure Optimization: Synthesis 173
5.6 Conclusion 175
References 175
6 Modeling Porous Media Transport, Heterogeneous Thermal Chemistry, and Electrochemical Charge Transfer 187
Robert J. Kee and Huayang Zhu
6.1 Introduction 187
6.2 Qualitative Illustration 189
6.3 Gas-Phase Conservation Equations 190
6.3.1 Gas-Phase Transport 191
6.3.2 Chemical Reaction Rates 191
6.3.3 Boundary Conditions 192
6.4 Ion and Electron Transport 192
6.5 Charge Conservation 194
6.5.1 Effective Properties 195
6.5.2 Boundary Conditions 195
6.5.3 Current Density and Cell Potential 196
6.6 Thermal Energy 196
6.7 Chemical Kinetics 196
6.7.1 Thermal Heterogeneous Kinetics 197
6.7.2 Charge Transfer Kinetics 198
6.7.3 Butler–Volmer Formulation 204
6.7.4 Elementary and Butler–Volmer Formulations 206
6.8 Computational Algorithm 207
6.9 Button Cell Example 207
6.9.1 Polarization Characteristics 208
6.9.2 Electric Potentials and Charged Species Fluxes 208
6.9.3 Anode Gas-Phase Profiles 212
6.9.4 Anode Surface Species Profiles 213
6.9.5 Applicability and Extensibility 214
6.10 Summary and Conclusions 214
6.10.1 Greek Letters 217
References 218
7 Evaluation of Models for Heterogeneous Catalysis 221
John Mantzaras
7.1 Introduction 221
7.2 Surface and Gas-Phase Diagnostic Methods 222
7.2.1 Surface Science Diagnostics 222
7.2.2 In Situ Gas-Phase Diagnostics 223
7.3 Evaluation of Hetero/Homogeneous Chemical Reaction Schemes 225
7.3.1 Fuel-Lean Combustion of Methane/Air on Platinum 225
7.3.1.1 Heterogeneous Kinetics 225
7.3.1.2 Gas-Phase Kinetics 228
7.3.2 Fuel-Lean Combustion of Propane/Air on Platinum 231
7.3.3 Fuel-Lean Combustion of Hydrogen/Air on Platinum 234
7.3.4 Fuel-Rich Combustion of Methane/Air on Rhodium 238
7.3.5 Application of Kinetic Schemes in Models for Technical Systems 240
7.4 Evaluation of Transport 242
7.4.1 Turbulent Transport in Catalytic Systems 243
7.4.2 Modeling Directions in Intraphase Transport 245
7.5 Conclusions 246
References 248
8 Computational Fluid Dynamics of Catalytic Reactors 251
Vinod M. Janardhanan and Olaf Deutschmann
8.1 Introduction 251
8.2 Modeling of Reactive Flows 253
8.2.1 Governing Equations of Multicomponent Flows 253
8.2.2 Turbulent Flows 256
8.2.3 Three-Phase Flow 256
8.2.4 Momentum and Energy Equations for Porous Media 257
8.3 Coupling of the Flow Field with Heterogeneous Chemical Reactions 258
8.3.1 Given Spatial Resolution of Catalyst Structure 258
8.3.2 Simple Approach for Modeling the Catalyst Structure 259
8.3.3 Reaction Diffusion Equations 260
8.3.4 Dusty Gas Model 261
8.4 Numerical Methods and Computational Tools 262
8.4.1 Numerical Methods for the Solution of the Governing Equations 263
8.4.2 CFD Software 264
8.4.3 Solvers for Stiff ODE and DAE Systems 264
8.5 Reactor Simulations 264
8.5.1 Flow through Channels 265
8.5.2 Monolithic Reactors 268
8.5.3 Fixed Bed Reactors 271
8.5.4 Wire Gauzes 273
8.5.5 Catalytic Reactors with Multiphase Fluids 273
8.5.6 Material Synthesis 275
8.5.7 Electrocatalytic Devices 277
8.6 Summary and Outlook 278
References 279
9 Perspective of Industry on Modeling Catalysis 283
Jens R. Rostrup-Nielsen
9.1 The Industrial Challenge 283
9.2 The Dual Approach 285
9.3 The Role of Modeling 287
9.3.1 Reactor Models 287
9.3.2 Surface Science and Breakdown of the Simplified Approach 288
9.3.3 Theoretical Methods 290
9.4 Examples of Modeling and Scale-Up of Industrial Processes 291
9.4.1 Ammonia Synthesis 291
9.4.2 Syngas Manufacture 294
9.4.2.1 Steam Reforming 294
9.4.2.2 Autothermal Reforming 297
9.5 Conclusions 298
References 300
10 Perspectives of the Automotive Industry on the Modeling of Exhaust Gas Aftertreatment Catalysts 303
Daniel Chatterjee, Volker Schmeißer, Marcus Frey, and Michel Weibel
10.1 Introduction 303
10.2 Emission Legislation 304
10.3 Exhaust Gas Aftertreatment Technologies 306
10.4 Modeling of Catalytic Monoliths 308
10.5 Modeling of Diesel Particulate Filters 313
10.6 Selective Catalytic Reduction by NH3 (Urea-SCR) Modeling 315
10.6.1 Kinetic Analysis and Chemical Reaction Modeling 316
10.6.1.1 NH3 Adsorption, Desorption, and Oxidation 316
10.6.1.2 NO-SCR Reaction 316
10.6.1.3 NH3–NO–NO2 Reactions 317
10.6.2 Influence of Washcoat Diffusion 319
10.7 Diesel Oxidation Catalyst, Three-Way Catalyst, and NOx Storage and Reduction Catalyst Modeling 319
10.7.1 Diesel Oxidation Catalyst 320
10.7.2 Three-Way Catalyst 321
10.7.3 NOx Storage and Reduction Catalyst 321
10.7.3.1 Species Transport Effects Related to NSCR: Shrinking Core Model 326
10.7.3.2 NH3 Formation During Rich Operation within a NSRC 327
10.8 Modeling Catalytic Effects in Diesel Particulate Filters 328
10.9 Determination of Global Kinetic Parameters 329
10.10 Challenges for Global Kinetic Models 330
10.11 System Modeling of Combined Exhaust Aftertreatment Systems 331
10.12 Conclusion 335
References 339
Index 345