Metal Oxides: Chemistry and Applications (Chemical Industries Book 108)

Interest in catalytic applications continue to grow in a variety of disciplines as researchers find even more links to other fields in basic science and in commercial applications. This collection of the 23 papers that serve as chapters here include recent work on metal oxides, including such topics as the molecular structures of surface oxide species, nanostructured supported metal oxides, defect chemistry and transport, surface processes and composition, the electronic structure of metal oxides, surface acidity and basicity, optical basicity, cation valence states analyzed by spectroscopy, investigation through methanol chemisorption, combinatorial approaches, methane oxidation, metathesis of olefins, applications of metal oxides for volatile organic compound combustion, selective catalytic reduction processes, gas sensors based on semiconducting metal oxides, and fuel electrodes for solid oxide fuel cells. Front cover......Page 1 Preface......Page 12 Editor......Page 14 Contributors......Page 16 Contents......Page 20 1 Molecular Structures of Surface Metal Oxide Species: Nature of Catalytic Active Sites in Mixed Metal Oxides......Page 24 1.2 Supported Metal Oxides......Page 25 1.2.1 Hydrated Surface Metal Oxide Species......Page 26 1.2.2 Dehydrated Surface Metal Oxide Species......Page 30 1.2.3 Surface Metal Oxide Species in Reactive Environments......Page 46 1.4 Bulk Mixed Metal Oxides......Page 47 1.5 Conclusions......Page 48 REFERENCES......Page 49 2.1 INTRODUCTION......Page 54 2.2.2 Ion exchange......Page 56 2.2.6 Other Methods......Page 57 2.3 CATALYST MOLECULAR STRUCTURE......Page 58 2.4 CASE STUDY: TUNGSTATED ZIRCONIUM OXIDE......Page 59 2.4.1 Surface Coverage......Page 61 2.4.2 Molecular Structure of WOx Species......Page 63 2.4.3 Relationship Between WOx Surface Structure and Catalytic Properties......Page 64 2.5.1 Surfactant Templating......Page 67 2.5.2 NP Surfactant Templating......Page 69 2.5.3 Modified Sol–Gel Chemistry......Page 70 2.6 CONCLUSIONS......Page 71 REFERENCES......Page 72 3.1 INTRODUCTION......Page 78 3.2.1 Point Defects......Page 79 3.2.2 Electronic Defects......Page 82 3.2.3 Nonstoichiometry......Page 88 3.3 DIFFUSION AND ELECTRICAL CONDUCTIVITY IN METAL OXIDES......Page 90 3.4 MIXED IONIC AND ELECTRONIC CONDUCTING MATERIALS......Page 95 3.4.1 Transport in MIEC Membranes......Page 96 3.4.2 Fabrication and Characterization of MIEC Membranes......Page 99 REFERENCES......Page 105 4.1 INTRODUCTION......Page 110 4.2 PRINCIPLE OF EELS MEASUREMENTS......Page 112 4.3 IN SITU OBSERVATION OF VALENCE STATE TRANSITION......Page 114 4.4 QUANTIFICATION OF OXYGEN VACANCIES IN CMR OXIDES......Page 117 4.5 REFINING THE CRYSTAL STRUCTURES OF NONSTOICHIOMETRIC OXIDES......Page 118 4.6 IDENTIFYING THE STRUCTURE OF NANOPARTICLES......Page 121 4.7 EXPERIMENTAL APPROACH FOR MAPPING THE VALENCE STATES OF CO AND MN......Page 122 4.8 MAPPING THE VALENCE STATES OF CO USING THE WHITE-LINED RATIO......Page 125 4.9 IN SITU OBSERVATION OF VALENCE STATE TRANSISTION OF MN......Page 129 4.10 PHASE SEPARATION USING THE NEAR-EDGE FINE STRUCTURE......Page 130 4.11 SUMMARY......Page 131 REFERENCES......Page 132 5.1 INTRODUCTION......Page 134 5.2.1 Surface Hydroxyl Site Densities......Page 136 5.2.2 Dehydroxylation of Metal Oxide Surfaces......Page 139 5.3 CARBONATION......Page 141 5.4.1 Solid Solutions......Page 144 5.4.2 Inhomogeneous Distribution of Metal Oxides in Porous Media......Page 147 5.4.3 Aggregation Phenomena in Supported Oxides......Page 150 REFERENCES......Page 151 6 The Electronic Structure of Metal Oxides......Page 156 6.1 INTRODUCTION......Page 157 6.2.1 The Ionic Model......Page 158 6.2.2 Orbital Energies and Covalent Interactions......Page 160 6.3 CALCULATIONS......Page 164 6.4.1 Electronic Structures of Metal Centered Tetrahedra......Page 165 6.4.2 Electronic Structures of Metal Centered Octahedra......Page 169 6.4.3 Octahedra and Tetrahedra Containing dn (n = 0) Transition Metal Cations......Page 171 6.4.4 Electronically Driven Geometric Distortions: 1st and 2nd Order Jahn–Teller Distortions......Page 173 6.5 BASIC CONCEPTS OF ELECTRONIC BAND THEORY......Page 174 6.5.1 The Electronic Band Structure of a One-Dimensional MO Chain......Page 175 6.5.2 Density of States Plots......Page 180 6.5.3 Conductivity, Carrier Mobility, and Their Relationship to the Band Structure......Page 181 6.5.4 The Electronic Band Structure of a Two-Dimensional CuO2− Layer......Page 183 6.5.5 The Electronic Band Structure of a Three-Dimensional WO3 Cubic Lattice......Page 186 6.6 ELECTRONIC BAND STRUCTURES OF PEROVSKITES......Page 190 6.6.1 Cubic Perovskites with Transition Metal Ions: Semiconductors and Metals......Page 191 6.6.2 Cubic Perovskites with MainGr oup Ions......Page 194 6.6.3 Distorted Perovskites: NaTaO3, CaSnO3, and CdSnO3......Page 196 6.7 ELECTRONIC BAND STRUCTURES OF BINARY OXIDES USED AS TRANSPARENT CONDUCTORS......Page 200 6.7.1 The Electronic Structure of SnO2......Page 201 6.7.2 The Electronic Structure of ZnO......Page 205 6.7.3 The Electronic Structure of CdO......Page 207 6.7.4 The Link between Conduction Band Width and OxygenCoor dination......Page 209 6.7.5 Generality of the Anion Coordination — Bandwidth Connection......Page 212 REFERENCES......Page 213 7.1 INTRODUCTION......Page 218 7.2.1 Electronic Structure of Metal Oxides......Page 220 7.2.2 Magnetic Interactions in Metal Oxides......Page 223 7.2.3 Magnetic Properties in Cuprates and Manganites......Page 225 7.3.1 Optical Conductivity......Page 228 7.3.2 Raman Scattering......Page 230 7.3.3 Resonant X-Ray Scattering......Page 232 REFERENCES......Page 234 8.1 INTRODUCTION......Page 238 8.2 REDOX CATALYSTS......Page 239 8.3 ACID–BASE AND REDOX PROPERTIES......Page 242 8.4 NATURE OF OXYGEN SPECIES......Page 243 8.5 STUDIES OF REDOX CHARACTERISTICS......Page 245 8.6 REDOX CATALYSTS — CASE STUDIES......Page 247 8.6.1 Vanadium Oxide-Based Catalysts......Page 248 8.6.2 Cerium Oxide-Based Catalysts......Page 254 8.6.3 Redox Behavior of Mixed Oxides......Page 257 8.7 CONCLUSIONS......Page 258 REFERENCES......Page 259 9 The Surface Acidity and Basicity of Solid Oxides and Zeolites......Page 270 9.1 INTRODUCTION......Page 271 9.2.1 Definitions of Acidity and Basicity......Page 272 9.2.2 Ionicity/Covalency and the Structures of Solid Oxides......Page 273 9.2.3 Acidity and Basicity on the Ideal Surface of a Solid Oxide......Page 275 9.2.4 Amount, Strength, and Distribution of Surface Acid and Basic Sites on the Ideal Surface of a Solid Oxide......Page 276 9.3.1 Molecular Probes for Surface Acidity and Basicity Characterization......Page 277 9.3.2 Quantitative Adsorption of Probe Molecules from Gas and Liquid Phases......Page 279 9.3.3 Calorimetric Methods......Page 280 9.3.4 Temperature Programmed Desorption Methods......Page 281 9.3.5 IR Spectroscopic Methods......Page 282 9.3.6 Nuclear Magnetic Resonance (NMR) Spectroscopic Methods......Page 286 9.3.8 Catalytic Probe Reactions......Page 288 9.4.1 Lewis Acid Strength......Page 289 9.4.2 Density of Lewis Sites......Page 291 9.4.4 Brønsted Acidity......Page 292 9.5.1 The Aluminas......Page 295 9.5.2 The “Mixed Oxides” of Silicon and Aluminum: Composition and Structure Properties......Page 303 9.5.3 Cationic Zeolites and Other Metal-Containing Zeolite-Like Structures......Page 316 9.5.4 Sulfated and Tungstated Zirconia: True Superacids?......Page 319 9.5.5 Solid Basic Catalysts: Oxides Containing Alkali, Alkali-Earth, and Rare Earth Cations......Page 321 REFERENCES......Page 323 10 Optical Basicity: A Scale of Acidity/Basicity of Solids and Its Application to Oxidation Catalysis......Page 342 10.1 INTRODUCTION......Page 343 10.2.1 After Duffy......Page 345 10.2.2 Mixed Oxides......Page 348 10.2.3 Surface Evaluation of Optical Basicity......Page 350 10.3 IONIZATION POTENTIAL AND SELECTIVITY......Page 352 10.4.1 Correlations between A And Experimental Values of Selectivity......Page 354 10.4.2 Linear [AI. A] Correlations: Alkanes and Alkyl-Aromatics......Page 355 10.4.4 Combustion of Paraffins and of Olefins......Page 360 10.5 THEORETICAL ASPECTS......Page 364 10.5.1 Attempts to Give a Thermodynamic Definition of Optical Basicity......Page 365 10.5.2 Attempts to Account for Linear Relationships Between Ionization Potential of Molecules and Optical Basicity of Catalysts......Page 366 10.6 CONCLUSION......Page 368 REFERENCES......Page 369 11 Investigation of the Nature and Number of Surface Active Sites of Supported and Bulk Metal Oxide Catalysts through Methanol Chemisorption......Page 376 11.1 INTRODUCTION......Page 377 11.2.1 Redox Sites Selective Molecular Probes......Page 378 11.2.2 Acid–Base Sites Selective Molecular Probes......Page 381 11.2.3 Super-Acid Sites of Heteropoly-Oxo Compounds......Page 382 11.3 DESIGNING A TAILORED MOLECULAR PROBE FOR A SPECIFIC APPLICATION......Page 383 11.3.1 Surface Reaction Mechanism of Methanol Adsorption-Reaction on Oxide Surfaces......Page 384 11.3.2 Saturation of the Oxide Surface with Reactive Surface Intermediate Species......Page 388 11.3.3 Measurementof the Amountof Surface Reactive Intermediate Species for the Determination of the Density of Surface Active Sites......Page 390 11.4.1 Stoichiometry of Methanol Adsorption and “Ligand Effect” of Monolayer Supported Metal Oxide-Based Catalysts......Page 392 11.4.2 Surface Morphology of Bulk Metal Oxide Catalysts......Page 394 11.4.3 Surface Composition of Bulk Metal Molybdate and Vanadate Catalysts......Page 396 11.4.4 Monolayer Supported versus Bulk Oxide Catalysts: Which is More Active?......Page 398 11.5 ISOPROPANOL AS A PROBE MOLECULE: REDOX VERSUS ACID PROPERTIES OF OXIDE CATALYSTS......Page 401 11.5.1 Isopropanol Adsorption over One-Component Bulk Metal Oxides......Page 402 11.5.2 Super-Acid Properties of Complex Heteropoly-Oxo Metallates......Page 404 11.6 FINAL REMARKS: THE FUTURE ON SURFACE SCIENCE THROUGH MOLECULAR PROBES......Page 408 REFERENCES......Page 409 12.1 INTRODUCTION......Page 414 12.2 STRATEGIES IN HIGH-THROUGHPUT EXPERIMENTATION......Page 416 12.2.1 Substrate-Based Approaches......Page 417 12.2.2 Substrate-Free Approaches......Page 418 12.3 SPECIFIC TECHNIQUES 12.3.1 Sputter or Evaporation Procedures......Page 419 12.3.2 Hydrothermal Reactions......Page 420 12.3.3 Sol–Gel Synthesis......Page 422 12.3.4 Precipitation Procedures......Page 423 12.3.5 Activated Carbon Route......Page 424 12.3.6 Split-and-Pool Synthesis......Page 425 REFERENCES......Page 431 13 Propane Selective Oxidation to Propene and Oxygenates on Metal Oxides......Page 436 13.1 INTRODUCTION......Page 437 13.2 ACRYLIC ACID — INDUSTRIAL APPLICATION AND PRODUCTION......Page 438 13.3 CHARACTERISTICS OF PROPANE OXIDATION REACTION......Page 440 13.4 CATALYSTS FOR SELECTIVE OXIDATION OF PROPANE......Page 444 13.4.1 Vanadium Phosphorous Oxides Catalysts......Page 445 13.4.2 Heteropolyoxometallic Compounds......Page 447 13.4.3 Multicomponent Mixed Metal Oxides......Page 451 13.4.4 Zeolites and Molecular Sieves......Page 457 13.5.1 Experimental......Page 461 13.5.2 Results......Page 463 CONCLUSIONS......Page 475 REFERENCES......Page 478 14.1 INTRODUCTION......Page 486 14.2 CH4 ACTIVATION OF METAL OXIDES......Page 488 14.3 METHANE COMBUSTION 14.3.1 Single Metal Oxides......Page 489 14.3.2 Double Oxides......Page 490 14.3.3 Doped Metal Oxides......Page 492 14.3.4 Hexaaluminate Materials......Page 493 14.4 OXIDATIVE COUPLING OF METHANE......Page 494 14.4.1 Catalytic Systems......Page 495 14.4.3 Prospects and Opportunities......Page 496 14.5.1 Silica......Page 497 14.5.2 RedoxOx ides......Page 499 OUTLOOK......Page 504 REFERENCES......Page 505 15.1 INTRODUCTION......Page 514 15.2 MECHANISMS OF THE ODH REACTIONS......Page 516 15.3.1 ODH of Ethane......Page 521 15.3.2 ODH of Propane......Page 525 15.3.3 ODH of n-Butane......Page 527 15.3.4 ODH of Isobutane......Page 529 15.3.5 Summary......Page 530 REFERENCES......Page 533 16.1 INTRODUCTION......Page 540 16.2 ROLE OF METAL-CARBENES IN METATHESIS REACTIONS......Page 543 16.3.1 Rhenium-Based Metathesis Catalysts......Page 544 16.3.2 Molybdenum-Based Metathesis Catalysts......Page 550 16.3.3 Tungsten-Based Metathesis Catalysts......Page 552 16.4 OLEFIN METATHESIS OVER NONTRANSISTION METAL OXIDES......Page 553 16.5 REACTION MECHANISM 16.5.1 ReactionP athways......Page 555 16.5.2 Theoretical Calculations......Page 557 16.6 SUMMARY......Page 558 REFERENCES......Page 559 17.1 INTRODUCTION......Page 566 17.2 VOCS OXIDATION OVER METAL OXIDES......Page 567 17.2.1 Perovskite Oxidesin VOCsOxidation......Page 573 17.2.3 Oxidation of Halogen Containing VOCs......Page 576 17.4 Carbon Deposition and VOCs Oxidation Activity......Page 578 REFERENCES......Page 580 18.1 INTRODUCTION......Page 592 18.2.1 Hydrogen......Page 594 18.2.2 Carbon Monoxide......Page 595 18.3 CARBON MONOXIDE HYDROGENATION......Page 599 18.3.1 CO Hydrogenation on Chromia–Zinc Oxides......Page 600 18.3.2 Strong Metal-Support Interactions......Page 601 18.3.3 Mixed Oxides......Page 602 18.4 HYDROGENATION OF CO/CO2 MIXTURES......Page 604 18.5 CARBON DIOXIDE HYDROGENATION 18.5.1 ActiveSiteand Roleof ZnO......Page 605 18.5.2 Cu–ZnO-Based Systems......Page 606 18.6 IN SITU STUDIES......Page 610 18.7 SUMMARY......Page 611 REFERENCES......Page 612 19.1 INTRODUCTION......Page 618 19.2 DESIGN AND DEVELOPMENT OF SECOND-GENERATION TI02 PHOTOCATALYSTS THAT CAN OPERATE UNDER VISIBLE LIGHT IRRADATION......Page 620 19.3 PHOTOCATALYTIC PERFORMANCE OF TITANIUM OXIDE-BASED THIN FILM CATALYSTS......Page 624 19.4 PHOTOCATALYTIC DECOMPOSITION OF WATER INTO H AND 02 USING TI02 THIN FILM PHOTOCATALYSTS......Page 630 19.5 LOCAL STRUCTURES OF THE ACTIVE SURFACE SITES OF TI-MCM-41 CATALYSTS AND THEIR PHOTOCATALYSTS REACTIVITY......Page 634 REFERENCES......Page 638 20 Photocatalytic Activity for Water Decomposition of RuO2-Dispersed p-Block Metal Oxides with d10 Electronic Configuration......Page 646 20.1 INTRODUCTION......Page 647 20.2 EXPERIMENTAL CONDITIONS......Page 648 20.3.2 Alkaline Earth Metal Indates[18]......Page 649 20.3.3 Lanthanum and Gadolinium Indates......Page 654 20.3.5 Role of the Local Structure of InO6......Page 655 20.3.6 Electronic Structures......Page 658 20.4 ZINC GALLATES, ZNGA2O4 [34]......Page 663 20.5 ZINC GERMANATE, Zn2GeO4 [37]......Page 670 20.6 ALKALINE EARTH METAL STANANTES ND ANTIMONATES......Page 673 20.7 CONCLUSION......Page 679 REFERENCES......Page 680 21.1 INTRODUCTION......Page 684 21.2.1 Ammonia versus Hydrocarbon as the Selective Reductant......Page 686 21.2.2 SCR on Metal Oxide Coupled to NonThermal Plasma......Page 688 21.2.3 NH3-SCR Processes for the Emissions from Combustion and Nitric Acid Plants......Page 689 21.2.4 The Question of Catalyst Activity in the NH3-SCR Process......Page 690 21.3.1 Metal Oxide Catalysts for the SCR-NH3 Process......Page 691 21.3.2 Reaction Mechanisms and Microkinetic Approaches to the SCR-NH3 Reaction......Page 694 21.4 SCR-HC......Page 697 REFERENCES......Page 702 22.1 INTRODUCTION......Page 706 22.2 SENSOR PERFORMANCE......Page 712 22.3 PRINCIPLE OF OPERATION......Page 718 22.3.1 Surface Chemistry and Charge Transfer......Page 722 22.3.2 Transduction: Contribution of Different Sensor Parts in the Sensing Process and Subsequent Transduction......Page 742 22.4 MULTIPLE FEATURE EXTRACTION APPROACH FOR GAS SENSING......Page 749 22.5 Conclusions......Page 751 REFERENCES......Page 752 23.1 INTRODUCTION......Page 762 23.2 CHOICE OF MATERIALS FOR SOFC ANODE......Page 764 23.3 FUELS FOR HIGH TEMPERATURE FUEL CELLS......Page 765 23.4.1 Reforming......Page 766 23.4.2 Direct Oxidation......Page 768 23.5.2 Cu–Zirconia and Cu–Ceria Anode Materials......Page 769 23.5.3 Alternative Anode Materials......Page 772 23.6 ANODE MATERIALS FOR DIRECT HYDROCARBON FUEL CELLS......Page 779 23.7 MICROSTRUCTURAL COMPROMISE......Page 781 FUTURE ANODE DEVELOPMENT......Page 782 REFERENCES......Page 783 Index......Page 790 Back cover......Page 808 The Chemistry Of Metals Has Traditionally Been More Understood Than That Of Its Oxides. As Catalytic Applications Continue To Grow In A Variety Of Disciplines, Metal Oxides: Chemistry And Applications Offers A Timely Account Of Transition-metal Oxides (tmo), One Of The Most Important Classes Of Metal Oxides, In The Context Of Catalysis. Drawing Insight From Leading International Experts, Metal Oxides: Chemistry And Applications Is A Comprehensive And Interdisciplinary Reference For Researchers That May Also Be Used By Newcomers As A Guide To The Field.--book Jacket. Computer Generated Contents: Chapt. 1. Molecular Structures Of Surface Metal Oxide Species: Nature Of Catalytic Active Sites In Mixed Metal Oxides -- Chapt. 2. Nanostructured Supported Metal Oxides -- Chapt. 3. Defect Chemistry And Transport In Metal Oxides -- Chapt. 4. Cation Valence States Of Transitional Metal Oxides Analyzed By Electron Energy-loss Spectroscopy -- Chapt. 5. Surface Processes And Composition Of Metal Oxide Surfaces -- Chapt. 6. The Electronic Structure Of Metal Oxides -- Chapt. 7. Optical And Magnetic Properties Of Metal Oxides -- Chapt. 8. Redox Properties Of Metal Oxides -- Chapt. 9. The Surface Acidity And Basicity Of Solid Oxides And Zeolites -- Chapt. 10. Optical Basicity: A Scale Of Acidity/basicity Of Solids And Its Application To Oxidation Catalysis -- Chapt. 11. Investigation Of The Nature And Number Of Surface Active Sites Of Supported And Bulk Metal Oxide Catalysts Through Methanol Chemisorption -- Chapt. 12. Combinatorial Approaches To Design Complex Metal Oxides -- Chapt. 13. Propane Selective Oxidation To Propene And Oxygenates On Metal Oxides -- Chapt. 14. Methane Oxidation On Metal Oxides -- Chapt. 15. Oxidative Dehydrogenation (odh) Of Alkanes Over Metal Oxide Catalysts -- Chapt. 16. Metathesis Of Olefins On Metal Oxides -- Chapt. 17. Applications Of Metal Oxides For Volatile Organic Compound Combustion -- Chapt. 18. Hydrogenation Of Carbon Oxides On Metal Oxides -- Chapt. 19. Photocatalysis: Photocatalysis On Titanium Oxide-based Catalysts -- Chapt. 20. Photocatalytic Activity For Water Decomposition Of Ruo2-dispersed P-block Metal Oxides With D10 Electronic Configuration -- Chapt. 21. Selective Catalytic Reduction (scr) Processes On Metal Oxides -- Chapt. 22. Gas Sensors Based On Semiconducting Metal Oxides -- Chapt. 23. Fuel Electrodes For Solid Oxide Fuel Cells. Edited By J.l.g. Fierro. Includes Bibliographical References And Index. The chemistry of metals has traditionally been more understood than that of its oxides. As catalytic applications continue to grow in a variety of disciplines, Metal Chemistry and Applications offers a timely account of transition-metal oxides (TMO), one of the most important classes of metal oxides, in the context of catalysis. The first part of the book examines the crystal and electronic structure, stoichiometry and composition, redox properties, acid-base character, and cation valence states, as well as new approaches to the preparation of ordered TMO with extended structure of texturally defined systems. The second part compiles some practical aspects of TMO applications in materials science, chemical sensing, analytical chemistry, solid-state chemistry, microelectronics, nanotechnology, environmental decontamination, and fuel cells. The book examines many types of reactions - such as dehydration, reduction, selective oxidations, olefin metathesis, VOC removal, photo- and electrocatalysis, and water splitting - to elucidate how chemical composition and optical, magnetic, and structural properties of oxides affect their surface reactivity in catalysis. Drawing insight from leading international experts, Metal Chemistry and Applications is a comprehensive and interdisciplinary reference for researchers that may also be used by newcomers as a guide to the field. The chemistry of metals has traditionally been more understood than that of its oxides. As catalytic applications continue to grow in a variety of disciplines, Metal Oxides: Chemistry and Applications offers a timely account of transition-metal oxides (TMO), one of the most important classes of metal oxides, in the context of catalysis. The first part of the book examines the crystal and electronic structure, stoichiometry and composition, redox properties, acid-base character, and cation valence states, as well as new approaches to the preparation of ordered TMO with extended structur