Part I Introduction
1 Bridging Materials and Pressure Gaps in Surface Science
and Heterogeneous Catalysis ................................ 3
Jeong Young Park and Gabor A. Somorjai
1.1 Introduction ............................................... 3
1.2 Materials and Pressure Gaps ................................ 4
1.3 Size, Shape, and Compositional Control of Colloid
Nanoparticles .............................................. 6
1.4 Control of Catalytic Reactions via Tuning the Size and
Composition of Bimetallic Nanoparticles .................... 8
1.5 In Situ Surface Characterization to Bridge Pressure Gaps .. 10
1.6 The Role of Metal-Oxide Interfaces in Heterogeneous
Catalysis ................................................. 14
1.7 Conclusion ................................................ 16
References ..................................................... 16
Part II Model Systems for Nanocatalysts to Bridge Materials Gap
2 Shape-Controlled Nanoparticles: Effect of Shape on
Catalytic Activity, Selectivity, and Long-Term Stability .. 21
Hyunjoo Lee
2.1 Why Does Shape Matter for Catalytic Reactions? ............ 21
2.2 The Synthesis of Shaped Nanocrystals ...................... 23
2.2.1 Colloidal Method ................................... 23
2.2.1.1 Surface-Capping Agent ..................... 24
2.2.1.2 Inorganic Shaping Agent ................... 25
2.2.1.3 Reducing Agent ............................ 26
2.2.1.4 Тор-Down Etching .......................... 26
2.2.2 Electrochemical Method ............................. 27
2.3 The Effect of Shape on Catalytic Activity, Selectivity,
and Long-Term Stability ................................... 27
2.3.1 Pt3Ni Nanooctahedra ................................ 28
2.3.2 Pt Nanodendrites ................................... 29
2.3.3 Pt-Based Nanocubes ................................. 30
2.3.4 Pt Overgrowth on Shaped Nanocrystals ............... 31
2.3.5 Selectivity Enhanced by Shape ...................... 33
2.3.6 Long-Term Stability Enhanced by Shape .............. 34
2.4 The Effect of the Surface-Capping Agent ................... 35
2.4.1 How the Catalytic Activity Can Be Varied by the
Surface-Capping Agents ............................. 35
2.4.2 Removal of the Surface-Capping Agents .............. 36
2.4.3 In Situ Shaping Without Surface-Capping Agents ..... 36
2.4.4 Participating in Catalytic Reactions ............... 37
2.5 Issues to Be Resolved ..................................... 38
2.5.1 Size: Facet vs. Edge/Step/Vertex ................... 38
2.5.2 Stability .......................................... 39
2.5.3 Mass Production .................................... 40
References ................................................ 40
3 Non-colloidal Nanocatalysts Fabricated with
Nanolithography and Arc Plasma Deposition ................. 45
Sang Hoon Kim and Jeong Young Park
3.1 Introduction .............................................. 45
3.2 Nanocatalysts Fabricated with Lithography ................. 46
3.2.1 Nanolithography for Fabrication of Nanodots and
Nanowires .......................................... 46
3.2.2 Catalytic Properties of Nanowires Fabricated with
Lithography ........................................ 48
3.3 Nanocatalysts Fabricated Via Arc Plasma Deposition ........ 50
3.3.1 Introduction to Arc Plasma Deposition .............. 50
3.3.2 Nanocatalysts on Two-Dimensional Supports Using
APD ................................................ 53
3.3.3 Nanocatalysts on Three-Dimensional Supports Using
APD ................................................ 55
3.3.4 Some New Applications for Nanoparticles Prepared
Via APD ............................................ 60
3.4 Summary and Outlook ....................................... 61
References ................................................ 61
4 Dendrimer-Encapsulated Metal Nanoparticles: Synthesis
and Application in Catalysis .............................. 65
Wenyu Huang
4.1 Introduction .............................................. 65
4.2 Synthesis of Dendrimer-Encapsulated Metal Nanoparticles ... 67
4.2.1 Synthesis of Monometallic DENs by Chemical
Reduction .......................................... 67
4.2.2 Synthesis of DENs in Organic Solutions ............. 69
4.2.3 Synthesis of DENs by Galvanic Redox Displacement ... 69
4.2.4 Synthesis of Bimetallic DENs ....................... 69
4.3 Recent Advancement in Understanding the Structure of
DENs ...................................................... 71
4.3.1 Metal Binding Sites for Pt2+ Ions .................. 71
4.3.2 Oxidation State of Pt DENs ......................... 72
4.3.3 Glass Nature of the Cluster ........................ 76
4.4 Newly Developed Applications of DENs in Catalysis ......... 77
4.4.1 Removal of Dendrimers for Heterogeneous Catalysis .. 77
4.4.2 Understanding the Nanoparticle Size Effect in
Catalysis .......................................... 79
4.4.3 Heterogenizing Homogeneous Catalysts and Their
Use in a Continuous Flow Reactor ................... 81
4.4.4 Increasing Diastereoselectivity and
Chemoselectivity ................................... 85
4.5 Summary and Outlook ....................................... 86
References ................................................ 87
5 Core-Shell Nanoarchitectures as Stable Nanocatalysts ...... 93
Sang Hoon Joo, Jae Yeong Cheon, and Joon Yong Oh
5.1 Introduction .............................................. 93
5.2 Metal/Metal Oxide Core-Shell Nanocatalysts ................ 95
5.2.1 Core-Shell Nanocatalysts with a Silica Shell ....... 95
5.2.2 Non-Siliceous Oxide Shells ......................... 99
5.3 Metal/Metal Oxide Yolk-Shell Nanocatalysts ............... 103
5.4 Supported Catalysts Coated with Shell Layers ............. 110
5.5 Summary and Future Perspectives .......................... 113
References ............................................... 115
6 Shape-Controlled Bimetallic Nanocatalysts in Fuel
Cells: Synthesis and Electrocatalytic Studies ............ 121
Yawen Zhang and Jun Gu
6.1 Introduction ............................................. 121
6.2 Classification of Bimetallic Nanocatalysts in Fuel
Cells .................................................... 122
6.3 Synthetic Routes to Bimetallic Nanocatalysts ............. 125
6.4 Key Factors to Control the Morphology of Bimetallic
Nanocrystals ............................................. 127
6.4.1 Reduction Rate of Metal Precursors ................ 127
6.4.2 Facet-Specific Capping Agents ..................... 129
6.4.3 Combination of Underpotential Deposition and the
Galvanic Replacement Reaction ..................... 133
6.5 Impact of Composition and Structure on Electrocatalytic
Performance .............................................. 134
6.5.1 Relationship Between Adsorption Strength and
Electrocatalytic Activity ......................... 134
6.5.2 Mechanisms of Tuning Adsorption Energy ............ 135
6.6 Summary .................................................. 138
References ............................................... 139
Part III In Situ Surface Characterization to Bridge Pressure
Gaps
7 Role of Surface Oxides on Model Nanocatalysts in
Catalytic Activity of CO Oxidation ....................... 145
Jeong Young Park, Kamran Qadir, and Sun Mi Kim
7.1 Introduction ............................................. 145
7.2 Pt Oxide ................................................. 146
7.3 Rh Oxide ................................................. 149
7.4 Ru Oxide ................................................. 153
7.4.1 CO Oxidation on Ru: From Single Crystals Towards
Nanoparticles ..................................... 153
7.4.2 Ru Oxide Powder and Supported Ru Catalysts ........ 155
7.4.3 Size Effect Under Catalytic Carbon Monoxide
Oxidation for Ru Nanoparticles .................... 156
7.4.4 Engineering Ru Oxide on Nanoparticles through
UV-Ozone Surface Treatment ........................ 157
7.4.5 Catalytic Activity of CO Oxidation on Ru
Nanoparticles and Ru Oxides Probed with Ambient
Pressure XPS ...................................... 159
7.5 Pd Oxide ................................................. 161
7.5.1 Pd Oxide on Single Crystal Surfaces ............... 161
7.5.2 CO Oxidation on Polycrystalline Palladium ......... 162
7.5.3 Oxidation Process of Pd(111) Probed by AP-XPS ..... 162
7.5.4 Pd Oxide on Nanoparticles ......................... 163
7.6 Concluding Remarks on the Role of Surface Oxide .......... 166
References ............................................... 166
8 Influence of Atomic Structure, Steps, and Kinks on the
Catalytic Activity: In Situ Surface Studies .............. 171
Bas Hendriksen
8.1 Single-Crystal Studies of Heterogeneous Catalysis ........ 171
8.2 Concepts and Theory: The Importance of Atomic-Scale
Structure ................................................ 172
8.2.1 Active Sites: Electronic and Geometric Effects .... 172
8.2.2 The Importance of the Gas Phase ................... 175
8.3 Atomic Structure and the Active Phase .................... 177
8.3.1 Structure-Sensitive Reactions ..................... 177
8.3.2 Oxides as the Active Phase ........................ 177
8.3.2.1 The Pressure-Gap Effect for Ruthenium .... 177
8.3.2.2 The Role of Oxides in CO Oxidation ....... 180
8.4 Steps and Kinks .......................................... 183
8.4.1 Step Decoration Experiments ....................... 184
8.4.2 СО-Induced Step Formation from UHV to
Atmospheric Pressure .............................. 185
8.4.3 Steps and the Catalytically Active Oxide Phase .... 188
8.5 Summary .................................................. 191
References ............................................... 191
9 The Development of Ambient Pressure X-Ray Photoelectron
Spectroscopy and Its Application to Surface Science ...... 197
Bongjin Simon Mun, Hiroshi Kondoh, Zhi Liu, Phil
N. Ross Jr., and Zahid Hussain
9.1 The Brief History of Ambient Pressure X-Ray
Photoelectron Spectroscopy ............................... 197
9.2 The First Development of Synchrotron-Based AP-XPS at
ALS ...................................................... 200
9.3 AP-XPS at ALS ............................................ 202
9.4 AP-XPS at Photon Factory ................................. 205
9.5 Oxidation Study of Transition Metal Single Crystals ...... 209
9.5.1 CO Oxidation on Pt(110) ........................... 209
9.5.2 NO Dissociation on Pt(111) ........................ 212
9.5.3 CO Oxidation on Pd(111) ........................... 217
9.6 Application to Real System: Solid Oxide Fuel Cell ........ 221
9.7 Concluding Remarks: Futures on AP-XPS .................... 223
References ............................................... 225
10 Electronic Excitation on Surfaces During Chemical and
Photon Processes ......................................... 231
Jeong Young Park
10.1 Introduction ............................................. 231
10.2 Theoretical Background of Energy Dissipation on
Surfaces ................................................. 232
10.3 Detection of Hot Electrons ............................... 234
10.3.1 Hot Electron Generation by Photons ................ 234
10.3.2 Hot Electron Generation by Transfer of Energetic
Molecules ......................................... 234
10.3.3 Hot Electron Generation by Electron Beams ......... 235
10.4 Detection of Hot Electrons from Exothermic Catalytic
Reactions ................................................ 237
10.4.1 Concept of Catalytic Nanodiodes ................... 238
10.4.2 Fabrication and Characterization of Metal-
Semiconductor Nanodiodes .......................... 239
10.4.1 Hot Electron Flows Detected on Catalytic
Nanodiodes Under Exothermic Catalytic Reaction .... 241
10.6 Hot Electron Flows Detected Upon Photon Absorption ....... 244
10.7 Influence of Hot Electrons on Surface Chemistry .......... 246
10.7.1 Influence of Hot Electrons on Atomic and
Molecular Processes ............................... 247
10.7.2 Hot Electron Effect on Metal-Oxide Hybrid
Nanocatalysts ..................................... 248
10.8 Concluding Remarks and Future Perspective ................ 251
References ............................................... 253
Index ......................................................... 259
|
