In-situ spectroscopy in heterogeneous catalysis / edited by James F. Haw.

Format:

Book

Contributor:

Haw, James F.

Language:

English

Subjects (All):

Heterogeneous catalysis.

Spectrum analysis.

Physical Description:

xii, 276 pages : illustrations ; 25 cm

Other Title:

In situ spectroscopy in heterogeneous catalysis

Place of Publication:

Weinheim : Wiley-VCH, [2002]

Contents:

1 Overview of In Situ Methods in Catalysis 1

1.2 Catalytic Materials 2

1.3 Compromises 4

1.3.1 Reactor Design 5

1.3.2 Catalyst Composition and Feed 7

1.3.3 Temperature 8

1.3.4 Theoretical Calculations

A Promising Future 9

1.4 Spectators 10

1.5 Future Prospects for In Situ Studies of Catalysis 10

1.6 My Introduction to In Situ Studies of Catalysis 11

2 In Situ Catalysis and Surface Science Methods 15

2.2 Surface Science Tools 16

2.2.1 Sum Frequency Generation (SFG)-surface specific vibrational spectroscopy 17

2.2.2 The high-pressure high-temperature Scanning Tunneling Microscope (STM) 19

2.3 Applications of In Situ Methods in Surface Science to Catalysis 20

2.3.1 High-Pressure SFG Studies 20

2.3.1.1 Ethylene hydrogenation on Pt(111) 20

2.3.1.2 Propylene hydrogenation and dehydrogenation on Pt(111) 26

2.3.1.3 Cyclohexene hydrogenation and dehydrogenation on Pt(111) and Pt(100) 31

2.3.1.4 CO oxidation on Pt(111) 36

2.3.2 High-Pressure STM Studies 42

2.3.2.1 High-pressure CO on Pt(111) [33] 42

2.3.2.2 High-pressure NO on Rh(111) 43

2.3.2.3 Tip-induced catalysis [36-38] 46

Preparation of hydrocarbon clusters 46

Tip-catalyzed hydrogenation of hydrocarbon clusters 47

Tip-catalyzed oxidation of hydrocarbon clusters 50

2.4 Challenges and Future Directions 51

3 In Situ NMR 53

3.2 Methods of In Situ NMR 55

3.2.1 General Considerations 55

3.2.2 In Situ NMR of Photocatalysis 56

3.2.3 In Situ NMR of Thermal Reactions in Sealed MAS Rotors 57

3.2.4 Sealed Rotors with Transient Heating 60

3.2.5 In Situ MAS Flow Probes 65

3.2.6 Magic-Angle Hopping Flow Probes 65

3.2.7 In Situ NMR using Quench Reactors 65

3.3 Applications of In Situ NMR to Methanol-to-Olefin Catalysis 70

3.3.2 HSAPO-34 Catalyst Structure 73

3.3.3 Pulse-Quench In Situ NMR of the Hydrocarbon Pool on HSAPO-34 75

3.3.4 Correlation of Product Selectivity (GC) with Catalyst Structure (NMR) 76

3.4 Some Limitations of In Situ NMR 78

4 Theoretical Catalysis: Methods, Applications, and Future Directions 87

4.2 Theoretical Methods 88

4.2.1 Classical Mechanics 88

4.2.1.1 Force fields 88

4.2.1.2 Classical mechanical techniques 90

Energy minimization 90

Monte Carlo simulation 91

Molecular dynamics simulation 91

4.2.1.3 Prediction of experimental data with classical mechanical methods 93

4.2.2 Quantum Mechanics 93

4.2.2.1 Semiempirical methods 93

4.2.2.2 Ab initio methods 94

4.2.2.3 Density functional theory 96

4.2.2.4 Prediction of experimental data by quantum mechanical methods 97

NMR properties 98

4.3 Model Systems 99

Our common quantum mechanical strategy 101

4.4 Applications of Theoretical Methods to Catalysis 101

4.4.1 Diffusion of Adsorbates in Silicalite 101

4.4.2 Theoretical Characterization of Zeolite Acidity 102

4.4.3 Solvent-Assisted Proton Transfer in Catalysis by Zeolite Solid Acids 105

4.4.4 Activation of Bronsted Acids by Lewis Acids: The Creation of New Solid Acid Catalysts 107

4.4.5 Carbenium Ion Chemistry on Solid Acids: Theoretical NMR 108

4.4.6 Base Catalysis by Metal Oxide Surfaces 110

4.5 Future Developments in Computational Catalysis 112

4.5.1 Computing Power 112

4.5.2 Approvements in General Methodology 112

4.5.3 Plane-Wave DFT 112

4.5.4 Combinatorial Catalysis 113

5 In Situ Ultraviolet Raman Spectroscopy 121

5.2 Instrumentation and Experimental Methods 124

5.2.1 The Spectrometer 124

5.2.2 The Fluidized Bed Sample Cell 125

5.2.3 Raman Tribometer 129

5.3 Two Examples of Results 130

5.3.1 Coke Formation in the Methanol-to-Gasoline Reaction 130

5.3.2 Lubricant Chemistry 133

6 In Situ Infrared Methods 139

6.2 Experimental Aspects 140

6.2.1 In situ cells for transmission spectroscopy 140

6.2.2 Diffuse Reflectance Spectroscopy 142

6.2.3 Infrared Emission Spectroscopy 143

6.2.4 Infrared Microspectroscopy 145

6.2.5 Reflection-Absorption Infrared Spectroscopy (RAIRS) 145

6.2.6 Sum Frequency Generation Spectroscopy (SFG) 146

6.2.7 Picosecond Infrared Spectroscopy 147

6.3 Recent Applications of in situ Infrared Spectroscopy 148

6.3.1 Zeolite Catalysts 148

6.3.1.1 Low-temperature bond migration in olefins 148

6.3.1.2 Methanol conversion over acid zeolites 151

6.3.1.3 Side-chain alkylation of toluene 156

6.3.1.4 Selective Catalytic Reduction (SCR) of NO[subscript x] 157

6.3.2 Oxide Catalysts 159

6.3.2.1 Selective catalytic reduction of NO by ammonia over vanadia/titania 159

6.3.2.2 In situ DRIFTS study of NO reduction by CH[subscript 4] over La[subscript 2]O[subscript 3] 162

6.3.2.3 Picosecond Infrared Spectroscopy on Single-Crystal Oxide Surfaces 164

6.3.3 Supported Metal Catalysts 166

6.3.3.1 Alkane reactions over bifunctional zeolites 166

6.3.3.2 DRITS study of NO decomposition over carbon-supported Rh and Pd 168

6.3.3.3 DRIFTS study of NO[subscript x] reduction by propene 168

6.3.4 Metal Surfaces 171

6.3.4.1 In situ RAIRS study of kinetic oscillations in the Pt(100) NO + CO system 171

6.3.4.2 RAIRS studies of electrocatalysis 173

6.4 Conclusions and Future Prospects 175

7 In Situ XAS Characterization of Heterogeneous Catalysts 179

7.1 Introduction: X-ray Absorption Spectroscopy (XAS) 179

7.2 Information Context of XAS 181

7.2.1 X-ray Absorption Near-Edge Spectrum (XANES) 181

7.2.1.1 Elemental analysis 181

7.2.1.2 Oxidation state and site symmetry 181

7.2.1.3 Empirical analysis of XANES 182

7.2.2 Extended X-ray Absorption Fine Structure (EXAFS) 183

7.3 Scope of Applicability of XAS 184

7.3.1 Applicability to Elements 184

7.3.1.1 Low-Z elements (C, N, O, and F) 185

7.3.1.2 Mg, Al, and Si 185

7.3.1.3 P, S, and Cl 186

7.3.1.4 High-energy edges (Z > 21) 186

7.3.2 Accessible In Situ Conditions 186

7.4 Mechanics of Measurement 187

7.4.1 The XAS Spectrometer

The Beamline 188

7.4.2 Detectors 188

7.4.2.1 Ion chambers 188

7.4.2.2 Solid-state detectors 188

7.4.2.3 Proportional counters 189

7.4.2.4 Electron yield detectors 189

7.5 Limitations 189

7.6 Examples of Applications 191

7.6.1 Mo/H-ZSM5 Catalyst for Non-oxidative CH[subscript 4] Reactions 191

7.6.2 Cu/ZnO Methanol Synthesis Catalyst 191

8 In Situ Measurement of Heterogeneous Catalytic Reactor Phenomena using Positron Emission 195

8.1.1 Positron Emission and Positron-Electron Annihilation 196

8.1.2 Detection Methods Based on Positron Emission 197

8.1.3 Positron Emission Tomography (PET), Particle Tracking (PEPT) and Profiling (PEP) 199

8.2 PEP Detectors and the Synthesis of Labeled Molecules Containing Positron-Emitting Isotopes 201

8.2.1 The TU/e PEP Detector 201

8.2.2 The Improved PEP Detector 203

8.2.3 Synthesis of Radiolabeled Molecules 206

8.2.3.1 [superscript 11]CO, [superscript 11]CO[subscript 2], [superscript 11]CH[subscript 3]C[subscript 5]H[subscript 11] 206

8.2.3.2 [superscript 13]NO, [superscript 13]NH[subscript 3] 208

8.2.3.3 [superscript 15]OO, N[subscript 2 superscript 15]O 208

8.3 Applications of PEP in Catalysis 209

8.3.1 Measurement of Mass Transfer and Adsorption Properties of Alkanes in Zeolite Packed-Bed Reactors 210

8.3.1.1 The labeled-pulse method (in situ tracer pulse chromatography) 210

Experimental details 211

Data analysis (modelling) 212

Numerical evaluation of the model 217

Results 218

8.3.1.2 By leak injection: tracer exchange positron emission profiling (TEX-PEP) 220

Experimental details 220

Modelling 222

Results 224

8.3.2 Measurement of the Reaction Kinetics of CO Oxidation on Pt/Ceria/Alumina Using [superscript 11]CO 225

8.3.2.1 Experimental details 225

8.3.2.2 Modelling 226

8.3.2.3 Results 229

8.4 Other (Potential) Applications of PEP in Catalysis Research 230

9 TAP Reactor Studies 237

9.1.1 What is the TAP Method? 237

9.1.2 How Can We Classify the TAP Method? 238

9.1.3 What is the TAP Method for? 239

9.2 Description and Operation of the TAP Reactor System 239

9.2.1 The TAP Reactor System 239

9.2.2 Types of Experiments 243

Single-pulse experiments to derive diffusivities (D[superscript eff subscript i]) and heats of adsorption ([delta]H[subscript ads]) 243

Series of pulse experiments from a single value 245

Series of sequential-pulse experiments from separate valves (two reactants) 246

Experiments with continuous viscous gas flow at low pressure (<10 mbar) 246

Experiments with continuous viscous gas flow at high pressure (1 to 3 bar) 246

Temperature-programmed experiments 247

Experiments with isotopes 248

9.3 Modeling the TAP Experiment 248

9.3.1 The Basis of TAP Pulse Modeling

Description of Gas Transport 249

9.3.2 Analytical Solution for TAP Pulse Experiments 250

9.3.3 Numerical Solution for TAP Pulse Experiments 251

9.3.4 Reactor Models 252

9.3.4.1 One-zone reactor model 252

Example of a simple adsorption

desorption

diffusion case 253

9.3.4.2 Three-zone reactor model 254

9.3.5 What is the Best Model? 254

9.4 Selected Applications in Heterogeneous Catalysis 255

9.4.1 Historical Overview 255

9.4.2 Investigation of Non-reactive Interactions of Gases with Solid Catalysts 256

9.4.2.1 Diffusion coefficients 256

9.4.2.2 Irreversible interaction 256

9.4.2.3 Reversible interaction 257

9.4.2.4 Competitive interaction of different gases 258

9.4.2.5 Adsorption/desorption properties in the presence of chemical reaction 259

9.4.3 Determination of Reaction Mechanisms 259

9.4.3.1 Reaction sequences 260

9.4.3.2 Information about gaseous short-lived intermediates 261

9.4.3.3 Information about adsorbed short-lived intermediates 262

9.4.3.4 Indentification of different active sites and properties of the reacting solid 264.

Notes:

Includes bibliographical references and index.

ISBN:

3527302484

OCLC:

47939452