Surface and Nanomolecular Catalysis

Using new instrumentation and experimental techniques that allow scientists to observe chemical reactions and molecular properties at the nanoscale, the authors of Surface and Nanomolecular Catalysis reveal new insights into the surface chemistry of catalysts and the reaction mechanisms that actually occur at a molecular level during catalysis. While each chapter contains the necessary background and explanations to stand alone, the diverse collection of chapters shows how developments from various fields each contributed to our current understanding of nanomolecular catalysis as a whole. The book describes how the size and shape of materials at the nanoscale can change their chemical and physical properties and promote more efficient reactions with fewer by-products. First it highlights the preparation, characterization, and applications of heterogeneous and supported metal catalysts. Then it covers the engineering of catalytic processes, structure and reaction control, and texturological properties of catalytic systems. The authors explain how surface science can elucidate reaction mechanisms and discuss the growing role of high-throughput experimentation and combinatorial approaches in catalysis. From fundamental concepts to future directions, Surface and Nanomolecular Catalysis offers a well-rounded compilation of noteworthy developments which will continue to expand and transform our understanding of catalysis, particularly in the context of clean energy and environmental applications such as fuel cells. SURFACE AND NANOMOLECULAR CATALYSIS......Page 1 Dedication......Page 3 Preface......Page 4 The Editor......Page 6 Contributors......Page 7 Contents......Page 9 CONTENTS......Page 11 Table of Contents......Page 0 1.2.1 X-Ray Diffraction......Page 12 1.2.2 X-Ray Absorption Spectroscopy......Page 13 1.2.3 Electron Microscopy......Page 15 1.3.1 Surface Area and Pore Structure......Page 17 1.3.2 Temperature-Programmed Desorption and Reaction......Page 18 1.3.3 Thermogravimetry and Thermal Analysis......Page 19 1.3.4 Microcalorimetry......Page 20 1.4.1 Infrared Spectroscopy......Page 22 1.4.2 Raman Spectroscopy......Page 23 1.4.3 Ultraviolet–Visible Spectroscopy......Page 25 1.4.4 Nuclear Magnetic Resonance......Page 26 1.4.5 Electron Spin Resonance......Page 28 1.5.1 X-Ray and Ultraviolet Photoelectron Spectroscopies......Page 29 1.5.2 Auger Electron Spectroscopy......Page 30 1.5.4 Secondary-Ion Mass Spectroscopy......Page 31 1.6 MODEL CATALYSTS......Page 32 1.7 CONCLUDING REMARKS......Page 35 REFERENCES......Page 36 Question 3......Page 42 Question 5......Page 43 Question 7......Page 44 Question 9......Page 45 Question 11......Page 46 Question 12......Page 47 CONTENTS......Page 48 2.2 PROPERTIES OF METAL OXIDES......Page 49 2.2.2 Insulators (Highly Ionic)......Page 50 2.2.4 Crystal Structures......Page 51 2.3.1 Surface Reconstruction......Page 53 2.3.2 Defect Sites......Page 55 2.4 SOLID ACIDS AND BASES......Page 57 2.4.2 Oxygen Anions as Lewis Bases......Page 58 2.4.4 Spectroscopic Methods of Detecting Lewis Acidity/Basicity and Bronsted Acidity/Basicity......Page 59 2.5.1.1 Hydrogen –Deuterium Exchange Reaction......Page 60 2.5.1.2 Hydrogenation (1,3-Butadiene + D2)......Page 61 2.5.1.5 Benzylation......Page 62 2.5.2.1 Oxidative Dehydrogenation — Vanadia......Page 63 2.5.2.2 Oxidative Coupling of Methane......Page 64 2.5.3.2 Freons......Page 65 REFERENCES......Page 66 Question 8......Page 70 3.1 INTRODUCTION......Page 71 3.3 MODES OF STABILIZATION......Page 72 3.4 REDUCTION METHODS......Page 74 3.5.2.1 Precursor Concept......Page 82 3.5.2.2 Conditioning: A Key Step in Generating Active Catalysts......Page 83 3.5.2.3 Heterogeneous Catalysts in Catalysis......Page 84 3.5.2.4 Fuel Cell Catalysts......Page 91 3.6 CONCLUSION......Page 93 REFERENCES......Page 94 Question 5......Page 102 CONTENTS......Page 103 4.1 SETTING THE SCENE......Page 104 4.3.1 What Are Zeolites?......Page 105 4.3.2.1 Zeolite X and Zeolite Y......Page 109 4.3.2.3 Mordenite......Page 110 4.3.3 Production of Zeolites......Page 111 4.3.4.1 Protonation of Zeolites......Page 113 4.3.4.3 Metals and Metal Complexes in Zeolites......Page 114 4.3.5 Catalytic Application of Zeolites......Page 115 4.3.5.1 Zeolite Catalysts in Petrochemical Processes......Page 117 4.3.5.1.1 Fluid Catalytic Cracking......Page 118 4.3.5.1.2 Hydrocracking......Page 121 4.3.5.1.3 Isomerization of n-Paraffins......Page 122 4.3.5.1.5 Aromatization of Liquefied Petrol Gases......Page 124 4.3.5.2 Methanol to Gasoline and Methanol to Olefins......Page 125 4.4.1 Ordered Mesoporous Silica Materials......Page 126 4.4.1.1 Surface Modifications of Ordered Mesoporous Silica Materials......Page 130 4.4.1.2 Catalysis with Ordered Mesoporous Silica Materials......Page 131 4.4.2 Nonsiliceous Ordered Mesoporous Materials......Page 133 4.5 CHARACTERIZATION OF MICROPOROUS AND MESOPOROUS MATERIALS......Page 134 4.5.1 X-Ray Diffraction......Page 135 4.5.2 Physisorption Analysis......Page 136 4.5.4 Nuclear Magnetic Resonance Spectroscopy......Page 138 4.5.5 Infrared Spectroscopy......Page 140 Terms and Abbreviations......Page 142 REFERENCES......Page 143 Problem 3......Page 146 Problem 7......Page 147 5.2 HISTORY......Page 148 5.3 PREPARATION......Page 149 5.3.1 Leaching Kinetics......Page 151 5.3.2 Promoters......Page 152 5.4 STRUCTURES......Page 154 5.5 DEACTIVATION / AGING......Page 156 5.6 APPLICATIONS......Page 158 5.7 ADVANTAGES / DISADVANTAGES......Page 160 REFERENCES......Page 161 Question 7......Page 166 6.1 INTRODUCTION......Page 167 6.2 EARLY PIONEERING WORK......Page 168 6.3.1 Qualitative Discrimination of Mechanisms......Page 172 6.3.2 pH Shift Modeling......Page 174 6.3.3 Metal Adsorption Modeling......Page 180 6.4.1 Survey of Pt/Silica Preparation Methods......Page 183 6.4.3 Uptake–pH Survey to Identify Optimal pH......Page 185 6.4.4 Tuning Finishing Conditions to Retain High Dispersion......Page 188 6.5 THE EXTENSION OF STRONG ELECTROSTATIC ADSORPTION TO ALUMINA AND CARBON......Page 191 6.6 FURTHER APPLICATIONS: OTHER OXIDES, BIMETALLICS......Page 193 REFERENCES......Page 196 Question 7......Page 198 Question 12......Page 199 ANNOTATIONS......Page 200 7.1 INTRODUCTION......Page 201 7.2 OVERVIEW OF HETEROGENEOUS CATALYSIS AND CHEMICAL REACTION ENGINEERING......Page 202 7.3 HYDROGEN PRODUCTION AND CLEANING: CATALYSIS AND REACTION ENGINEERING......Page 204 7.3.1.1 Fuel Reforming......Page 205 7.3.1.3 Preferential Oxidation of Carbon Monoxide......Page 207 7.3.2 Fuel Cells and Primary Fuel Processing for Low-Temperature Fuel Cells......Page 209 7.3.2.1 Catalytic Processes of Hydrogen Production for Proton-Exchange Membrane Fuel Cell......Page 210 7.3.2.1.1 Water-Gas Shift Reaction in Excess of H2 Over the Nanostructured CuxCe1-xO2-y Catalyst......Page 211 7.3.2.1.2 Selective CO Oxidation in Excess of H2 (PrOX) over the Nanostructured CuxCe1-xO2-y Catalyst......Page 219 ACKNOWLEDGMENTS......Page 229 REFERENCES......Page 230 Question 8......Page 232 Question 10......Page 233 8.1 INTRODUCTION......Page 234 8.2.1 Self-Assisted Dehydrogenation of Ethanol on an Nb/SiO2 Catalyst......Page 236 8.2.2 Reactant-Promoted Water-Gas-Shift Reactions......Page 238 8.2.2.1 WGS Reactions on ZnO......Page 239 8.2.2.2 WGS Reactions on Rh/CeO2......Page 240 8.2.3.1 Reaction Aspect of Methanol Oxidation......Page 241 8.2.3.2 Reaction Scheme of Methanol Oxidation in TPR......Page 245 8.2.3.4 Regulation of the Methanol Oxidation by Extra Oxygen Atoms......Page 247 8.3.1 Chemical Tuning of Active Sites......Page 249 8.3.2 ReOx Clusters Produced in Situ......Page 251 8.4.1 Reaction Regulation by Molecular Imprinting......Page 253 8.4.2 Design of a Reaction Intermediate on Catalyst Surface......Page 257 REFERENCES......Page 259 Problem 4......Page 261 CONTENTS......Page 262 9.1 INTRODUCTION......Page 263 9.2.1 Gibbsian Classical Thermodynamic Theory......Page 266 9.2.2 Flat Interface......Page 267 9.2.3 Curved Interface......Page 269 9.2.4 Surface Curvature......Page 270 9.2.5 The Limits of the Classic Thermodynamic Theory......Page 271 9.2.6.1 Fundamental Mechanisms of Texture Genesis......Page 272 9.2.6.2 Fundamental Processes of Texture Genesis......Page 274 9.3 ADSORPTION AS A PRIMARY INSTRUMENT FOR TEXTURE CHARACTERIZATION......Page 279 9.4.1 Density and Porosity......Page 285 9.4.2 Experimental Techniques of Measurements of True, Apparent, and Bulk Density......Page 288 9.4.3 The Properties of Porosity......Page 289 9.4.4 The Specific Surface Area......Page 294 9.5 MORPHO-DEPENDENT TEXTURAL PARAMETERS: MEAN SIZES OF PARTICLES AND PORES......Page 295 9.6.1 Morphology of Porous Solids and Problems with Modeling......Page 298 9.6.2 Classification of Porous Systems and Texture Modeling......Page 299 9.6.3 Generalized Models and Systematic Sets of Models......Page 304 9.7.1 Voronoi–Delaunay Method for Description of Corpuscular and Sponge-Like Porous Solids......Page 306 9.7.2 Ordered Packings......Page 311 9.7.3 Disordered Packings......Page 316 9.8 MODELING THE ENSEMBLES (CLUSTERS) OF PARTICLES AND PORES ON THE BASIS OF A FRACTAL APPROACH......Page 319 9.9.1 Percolation Theory......Page 325 9.9.1.1 Problem of Bonds......Page 326 9.9.1.2 Problem of Sites......Page 327 9.9.2 The Stochastic and other Statistical Models of Long-Range Order......Page 329 9.10 CONCLUSIONS......Page 332 REFERENCES......Page 333 Problem 6......Page 340 Problem 11......Page 341 10.1 INTRODUCTION......Page 342 10.1.1 Studies of CO Hydrogenation on Single-Crystal Surfaces......Page 343 10.1.1.1 Effects of Poisons and Promoters on CO Methanation......Page 344 10.1.3 Bimetallic Surfaces......Page 345 10.2 MODEL CATALYSTS......Page 349 10.2.1.2 Amorphous SiO2 Films......Page 350 10.2.1.4 Highly Defective TiOx Films......Page 353 10.2.2 Supported Metal Clusters (Au as an Example)......Page 354 10.3.1 Vibrational Spectroscopy......Page 360 10.3.3 Elevated Pressure XPS......Page 368 REFERENCES......Page 373 Question 10......Page 377 CONTENTS......Page 378 11.1 HIGH-THROUGHPUT EXPERIMENTATION AND COMBINATORIAL CATALYSIS — DEFINITION AND SCOPE......Page 379 11.2.1 Descriptor-Driven Approaches......Page 381 11.2.2 Approaches Based on Classical Statistical Designs......Page 382 11.2.3 Other Techniques for Finding Local Optima......Page 383 11.3 STAGE I AND STAGE II SCREENING......Page 385 11.4 ANALYTICAL TECHNIQUES FOR SCREENING......Page 387 11.5 SYNTHETIC APPROACHES FOR HIGH-THROUGHPUT EXPERIMENTATION AND COMBINATORIAL CHEMISTRY......Page 390 11.5.1 Synthetic Approaches for Molecular Catalysts......Page 391 11.5.2 Synthetic Approaches for Solid-State Inorganic Catalysts......Page 392 11.5.3 Combinatorial Synthetic Approaches for Solid-State Inorganic and Molecular Catalysts......Page 394 11.6 TESTING OF CATALYSTS IN GAS-PHASE REACTIONS......Page 395 11.6.1.2 Reactant Distribution for Stage I Screening Systems......Page 401 11.6.1.3 Single-Bead Reactors......Page 403 11.6.1.4 Optimal Use of Stage I in Screening Programs......Page 406 11.6.2 Stage II Testing in Gas-Phase Applications......Page 407 11.6.2.1 The Epoxidation of 1,3-Butadiene with Ag-Based Catalysts......Page 410 11.6.2.2 Dynamic Experiments in Stage II Screening for Automotive Applications......Page 412 11.6.2.3 Refinery Catalysis Applications in High-Throughput Experimentation......Page 414 11.6.2.3.1 Pressure Flow and Pressure Control......Page 415 11.7 TESTING OF CATALYSTS IN LIQUID–LIQUID, GAS–LIQUID, AND GAS–LIQUID–SOLID REACTIONS......Page 416 11.7.1 Stage I Screening for Liquid-Phase Catalysis......Page 418 11.7.1.1 Alternative Stage I Screening Concepts......Page 422 11.7.2 Stage II Screening for Liquid-Phase Catalysis......Page 423 11.8 SUMMARY AND OUTLOOK......Page 425 REFERENCES......Page 426 Question 7......Page 430 Question 11......Page 431 CONTENTS......Page 432 12.1 INTRODUCTION......Page 433 12.2 PHOTOCATALYSIS......Page 434 12.2.1 General Principles......Page 435 12.2.2 TiO2 Photocatalysts......Page 438 12.2.2.1 Preparation Procedures......Page 440 12.2.3 Modified Titania Photocatalysts......Page 443 12.2.5 Noble Metal Deposited on Titania Surfaces......Page 446 12.2.7 ZnO......Page 448 12.2.10 Polyoxometalates......Page 449 12.3 KINETIC STUDIES......Page 450 12.4 COMBINATORIAL APPROACHES IN PREPARATION AND TESTING PHOTOCATALYSTS......Page 451 12.5 EXAMPLE OF REACTIONS UNDER PHOTOCATALYTIC CONDITIONS......Page 453 12.5.1 Photoinduced Deposition of Various Metals onto Semiconductor......Page 454 12.7 SONOPHOTOCATALYSIS......Page 455 12.10 CONCLUSIONS......Page 457 REFERENCES......Page 458 Question 10......Page 466 13.1 INTRODUCTION......Page 467 13.2.2 Transition-Metal-Substituted Polyoxometalates......Page 469 13.2.3 Peroxometalates......Page 476 13.3 HETEROGENEOUS CATALYSTS WITH POLYOXOMETALATE-BASED COMPOUNDS......Page 478 13.3.1.1 Active Carbon......Page 479 13.3.1.2 Silica and MCM-41......Page 481 13.3.2.2 Alkylammonium Ions......Page 482 13.3.2.3 Crosslinking of Copolymer with POM......Page 483 13.3.3 Intercalation into Anion-Exchange Materials......Page 484 13.3.4.1 Anion–Cation Pairing......Page 486 13.3.4.3 Others......Page 488 13.4 CONCLUSIONS AND FUTURE OPPORTUNITIES......Page 489 REFERENCES......Page 491 Question 6......Page 496 14.1 INTRODUCTION......Page 497 14.2 PRINCIPLES OF STEREODIFFERENTIATION AND ASYMMETRIC CATALYSIS......Page 500 14.3 HISTORICAL DEVELOPMENTS......Page 503 14.4.1 Catalyst Preparation Process......Page 506 14.4.3 Substrate and Hydrogenation Parameters......Page 507 14.4.4 Mechanistic Investigations and Hypotheses for Enantioselection......Page 508 14.4.5 Proposed Mechanisms......Page 511 14.5 CHIRAL-MODIFIED PLATINUM HYDROGENATION CATALYSTS AND RELATED SYSTEMS......Page 514 14.5.2 Mechanistic Investigations......Page 516 14.6 HETEROGENEIZED HOMOGENEOUS CATALYSTS......Page 521 14.8 DIASTEREOSELECTIVE CATALYSIS......Page 523 REFERENCES......Page 527 Question 10......Page 535 At the moment the?rst issue of this book appears, hundreds of groups around the world are pushing the boundaries of the?eld of surface plasmon nanophotonics. The newfound ability to use metallic nanostructures to manipulate light at a length scale far below the diffraction limit has opened a myriad of exciting opportunities. Based on the exponentialincrease in the number of publishedpaperseveryyear(Chapter1), it is clear that we are at the eve of a new revolution that will impact many?elds of science and technology, including photonics, computation, the Internet, biology, medicine, materials science, physics, chemistry, and photovoltaics. Ithasbeenagreatpleasureandhonortoworkwithsomeoftheleadingscientistsin the?eld during the preparation of this work. The book truly re?ects the present status of this rapidly developing area of science and technology and highlights some of the important historic developments. Most of the chapters discuss ongoing scienti?c research, and promising future directions are identi?ed. Plasmon excitations in single and periodic arrays of metallic nanostructures are discussed in Chapters 2 and 3. The unique properties of metallic waveguides and metallo-dielectric photonic crystal structures that can route information on a chip are treated in Chapters 3 through 7. Surface Plasmon Mediated Field Concentration and Imaging methods, including - perlensesandnanoscaleopticalantennas, aredescribedinChapters8through10. The rapiddevelopmentsinnanoscaleopticalprobesthatcanvisualizethe?owoflightand new, powerfulelectromagneticsimulationtoolsaretreatedinChapters11through13. The?nal chapters (Chapters 14-17) analyze a set of exciting applications of surface plasmon nanophotonics with tremendous commercialization potential, ranging from biology to data storage, and integrated optics

Using new instrumentation and experimental techniques that allow scientists to observe chemical reactions and molecular properties at the nanoscale, the authors of Surface and Nanomolecular Catalysis reveal new insights into the surface chemistry of catalysts and the reaction mechanisms that actually occur at a molecular level during catalysis. While each chapter contains the necessary background and explanations to stand alone, the diverse collection of chapters shows how developments from various fields each contributed to our current understanding of nanomolecular catalysis as a whole.

The book describes how the size and shape of materials at the nanoscale can change their chemical and physical properties and promote more efficient reactions with fewer by-products. First it highlights the preparation, characterization, and applications of heterogeneous and supported metal catalysts. Then it covers the engineering of catalytic processes, structure and reaction control, and texturological properties of catalytic systems. The authors explain how surface science can elucidate reaction mechanisms and discuss the growing role of high-throughput experimentation and combinatorial approaches in catalysis.

From fundamental concepts to future directions, Surface and Nanomolecular Catalysis offers a well-rounded compilation of noteworthy developments which will continue to expand and transform our understanding of catalysis, particularly in the context of clean energy and environmental applications such as fuel cells.

This book discusses a new class of photonic devices, known as surface plasmon nanophotonic structures. The book highlights several exciting new discoveries, while providing a clear discussion of the underlying physics, the nanofabrication issues, and the materials considerations involved in designing plasmonic devices with new functionality. Chapters written by the leaders in the field of plasmonics provide a solid background to each topic.