Preface ........................................................ xi
Anders Nilsson, Lars G.M. Pettersson and Jens K. Norskov
1. Surface Structure ............................................ 1
D.P. Woodruff
1. Why surface structure? .................................... 1
2. Methods of surface adsorbate structure determination ...... 2
2.1. General comments ..................................... 2
2.2. Electron scattering .................................. 3
2.3. X-ray scattering ..................................... 6
2.4. Ion scattering ....................................... 8
2.5. Spectroscopic methods and scanning probe
microscopy ........................................... 9
3. Adsorbate-induced surface reconstruction ................. 11
4. Molecular adsorbates - local sites, orientations and
intramolecular bondlengths ............................... 19
4.1. General issues and the case of CO on metals ......... 19
4.2. Simple hydrocarbons on metals ....................... 21
4.3. Carboxylates on metals .............................. 26
4.4. Other substrates: molecules on Si ................... 33
5. Chemisorption bondlengths ................................ 38
5.1. Metal surfaces ...................................... 38
5.2. Oxide surfaces ...................................... 44
6. Conclusions .............................................. 48
2. Adsorbate Electronic Structure and Bonding on Metal
Surfaces .................................................... 57
Anders Nilsson and Lars G.M. Pettersson
1. Introduction ............................................. 57
2. Probing the electronic structure ......................... 58
3. Adsorbate electronic structure and chemical bonding ...... 63
4. Adsorbate systems ........................................ 68
5. Radical atomic adsorption ................................ 69
5.1. The electronic structure of N on Cu(100) ............ 70
5.2. Chemical bonding of atomic adsorbates ............... 75
6. Diatomic molecules ....................................... 79
6.1. N2 adsorbed on Ni(100) .............................. 80
6.2. CO adsorbed on Ni(100) .............................. 91
6.3. CO adsorbed on Cu(100) and other metals ............. 97
6.4. CO adsorbed in different sites ...................... 99
6.5. Coadsorption of CO and К on Ni(100) ................ 101
7. Unsaturated hydrocarbons ................................ 103
7.1. Ethylene (C2H4) adsorbed on Ni(l10) and Cu(110) .... 104
7.2. Benzene on Ni and Cu surfaces ...................... 1ll
7.3. Bond energetics and rehybridization from spin-
uncoupling ......................................... 113
8. Saturated hydrocarbons .................................. 119
8.1. n-Octane adsorbed on Cu(l10) ....................... 120
8.2. Difference between octane on Ni and Cu
surfaces ........................................... 126
9. Lone pair interactions .................................. 127
9.1. Water adsorption on Pt and Cu surfaces ............. 127
9.2. Adsorption of ammonia and the amino group in
glycine on Cu(l10) ................................. 131
10.Summary ................................................. 134
3. The Dynamics of Making and Breaking Bonds at Surfaces ...... 143
A.C. Luntz
1. Introduction ............................................ 143
2. Theoretical background .................................. 146
2.1. Adiabatic dynamics (Born-Oppenheimer
approximation) ..................................... 146
2.2. Generic PES topologies ............................. 149
2.3. Dynamics vs. kinetics .............................. 152
2.3.1. Direct dissociation ......................... 153
2.3.2. Precursor-mediated dissociation ............. 156
2.4. Detailed balance ................................... 157
2.5. Lattice coupling ................................... 158
2.5.1. Energy transfer in adsorption/scattering .... 159
2.5.2. Lattice coupling in direct molecular
dissociation ................................ 163
2.6. Non-adiabatic dynamics ............................. 164
2.6.1. Hot electrons from chemistry ................ 165
2.6.2. Chemistry from hot electrons ................ 169
3. Experimental background ................................. 172
3.1. Experimental techniques ............................ 173
3.2. Typical measurements ............................... 175
3.2.1. Rate measurements ........................... 175
3.2.2. Adsorption-trapping and sticking ............ 176
3.2.3. Desorption .................................. 179
3.2.4. Scattering .................................. 180
3.2.5. Initial state preparation ................... 181
3.2.6. Photochemistry/femtochemistry ............... 181
3.2.7. Single molecule chemistry (STM) ............. 182
4. Processes ............................................... 182
4.1. Atomic adsorption/desorption/scattering ............ 183
4.1.1. Ar/Pt(lll) .................................. 183
4.1.2. H/Cu(lll) ................................... 186
4.2. Molecular adsorption/desorption/scattering ......... 188
4.2.1. NO/Ag(ll1) .................................. 188
4.2.2. NO/Pt(l11) .................................. 195
4.3. Direct dissociation/associative desorption ......... 198
4.3.1. Activated dissociation ...................... 198
4.3.2. Weakly activated dissociation ............... 214
4.3.3. Non-activated dissociation .................. 216
4.4. Precursor-mediated dissociation/associative
desorption ......................................... 219
4.4.1. 02/Pt(lll) .................................. 219
4.5. Direct and precursor-mediated dissociation ......... 223
4.5.1. N2/W(100) ................................... 223
4.5.2. NH3/Ru(0001) ................................ 226
4.6. Langmuir-Hinschelwood chemistry .................... 227
4.6.1. (O + CO)/Pt(l11) ............................ 227
4.7. Eley-Rideal/Hot atom chemistry ..................... 230
4.7.1. H + H/Cu(lll) ............................... 230
4.8. Hot electron chemistry ............................. 235
4.8.1. Photochemistry/femtochemistry ............... 235
4.8.2. Single molecule chemistry ................... 240
5. Summary and outlook ..................................... 242
4. Heterogeneous Catalysis .................................... 255
T. Bligaard and J.K. Nørskov
1. Introduction ............................................ 255
2. Factors determining the reactivity of a transition
metal surface ........................................... 256
3. Trends in adsorption energies on transition metal
surfaces ................................................ 257
4. The d-band model ........................................ 259
4.1. One-electron energies and bond energy trends ....... 259
4.2. The Newns-Anderson model ........................... 262
5. Trends in chemisorption energies ........................ 267
5.1. Variations in adsorption energies from one
metal to the next .................................. 267
5.2. Ligand effects in adsorption - changing the d
band center ........................................ 269
5.2.1. Variations due to changes in surface
structure ................................... 270
5.2.2. Variations due to alloying .................. 273
5.3. Ensemble effects in adsorption - the
interpolation principle ............................ 275
6. Trends in activation energies for surface reactions ..... 278
6.1. Electronic effects in surface reactivity ........... 279
6.2. Geometrical effects in surface reactivity .......... 281
7. Bronsted-Evans-Polanyi relationships in heterogeneous
catalysis ............................................... 283
7.1. Correlations from DFT calculations ................. 283
7.2. Universal relationships ............................ 285
8. Activation barriers and rates ........................... 287
8.1. Transition state theory ............................ 288
8.2. Variational transition state theory and
recrossings ........................................ 291
8.3. Harmonic transition state theory (HTST) ............ 292
9. Variations in catalytic rates - volcano relations ....... 297
9.1. Dissociation rate-determined model ................. 298
9.2. A Le Chatelier-like principle for heterogeneous
catalysis ......................................... 302
9.3. Including molecular precursor adsorption ........... 303
9.4. Sabatier analysis .................................. 305
9.5. A realistic desorption model ....................... 307
9.6. Database of chemisorption energies ................. 311
10 The optimization and design of catalyst through
modeling ................................................ 312
10.1.The low-temperature water gas shift (WGS)
reaction ........................................... 313
10.2.Methanation ........................................ 313
11 Conclusions and outlook ................................. 316
5 Semiconductor Surface Chemistry ............................ 323
Stacey F. Bent
1. Inroduction ............................................. 323
2. Structure of semiconductor surfaces ..................... 325
2.1. Silicon surface structure .......................... 326
2.2. Germanium surface structure ........................ 330
3. Surface oxidation ....................................... 331
3.1. Silicon ............................................ 331
3.2. Germanium .......................................... 333
4. Passivation of semiconductor surfaces ................... 334
4.1. Silicon passivation ................................ 334
4.4.1. Hydride termination of silicon .............. 334
4.2. Germanium passivation .............................. 335
4.2.1. Sulfide passivation of germanium ............ 336
4.2.2. Chloride passivation of germanium ........... 337
4.2.3. Hydride termination of germanium ............ 337
5. Reactions at passivated semiconductor surfaces .......... 339
5.1. Organic functionalization of semiconductor
surface ............................................ 339
5.2. Reaction with passivated silicon (Si-H and
Si-Cl) ............................................. 339
5.2.1. Hydrosilylation ............................. 339
5.2.2. Grignard reactions on silicon ............... 345
5.3. Reaction with passivated germanium (Ge-H and
Ge-Cl) ............................................. 346
5.3.1. Grignard reactions on germanium ............. 347
5.3.2. Hydrogermylation ............................ 348
5.3.3. Alkanethiol reactions on germanium .......... 349
5.4. Reaction with compound semiconductors .............. 350
6. Adsorption of organic molecules under vacuum
conditions .............................................. 351
6.1. Silicon surface chemistry .......................... 352
6.1.1. Cycloaddition reaction on Si(100)-2 x 1 ..... 352
6.1.2. Heterocycloadditions ........................ 361
6.1.3. Nucleophilic/electrophilic reactions ........ 362
6.2. Germanium surface chemistry ........................ 369
6.2.1. Cycloaddition reactions on Ge(100)-2 x 1 .... 370
6.2.2. Heterocycloadditions ........................ 372
6.2.3. Nucleophilic/electrophilic reactions ........ 374
6.2.4. Multiple-layer reactions .................... 376
6.3. Summary of concepts in organic functionalization ... 378
6 Surface Electrochemistry ................................... 397
Peter Strasser, Hirohito Ogasawara
1. Introduction ............................................ 397
2. Special features of electrochemical reactions ........... 398
2.1. Electrochemical current and potential .............. 399
2.2. Electrochemical interfaces ......................... 404
2.3. Models of electrochemical electron transfer
kinetics ........................................... 406
3. Electrochemistry at the molecular scale ................. 412
3.1. Surface structure .................................. 412
3.2. Bonding of ions .................................... 413
3.3. Bonding of water ................................... 415
3.4. Experimental aspects of current/voltage
properties ......................................... 416
4. Electrocatalytic reaction processes ..................... 418
4.1. The electrocatalytic reduction of oxygen ........... 420
4.1.1. Background .................................. 420
4.1.2. Mechanistic pathways ........................ 422
4.1.3. Electroreduction of oxygen on Pt and Pt
alloys ...................................... 423
4.1.4. Recent quantum chemical studies of the ORR
mechanism ................................... 425
4.1.5. State-of-the-art ORR electrocatalyst
concepts .................................... 431
4.2. The electrochemical oxidation of small organic
molecules .......................................... 435
4.2.1. The electrooxidation of carbon monoxide ..... 438
4.2.2. The electrooxidation of formic acid and
methanol .................................... 444
5. Summary and outlook .................................. 448
7. Geochemistry of Mineral Surfaces and Factors Affecting
Their Chemical Reactivity .............................. 457
Gordon E. Brown, Jr., Thomas P. Trainor, Anne M. Chaka
1. Introduction ............................................ 457
2. Environmental interfaces ................................ 461
2.1. Common minerals in Earth's crust, soils, and
atmosphere, weathering mechanisms and products, and
less common minerals that contain or adsorb
environmental contaminants ......................... 461
2.2. Solubilities of Al- and Fe(III)-oxides and Al and
Fe(III)-(oxy)hydroxides ............................ 466
2.3. Dissolution mechanisms at feldspar-water
interfaces ......................................... 469
2.4. The nature of metal oxide-aqueous solution
interfaces - some basics ........................... 472
3. Factors affecting the chemical reactivity of mineral
surfaces ................................................ 478
3.1. The reaction of water vapor with metal oxide
surfaces - surface science and theoretical
studies of simplified model systems illustrating
effects of defect density and adsorbate
cooperative effects ................................ 479
3.2. Grazing incidence EXAFS spectroscopic studies of
Pb(II)aq adsorption on metal oxide surfaces -
effect of differences in surface functional
groups on reactivity ............................... 484
3.3. The structure of hydrated metal oxide surfaces
from X-ray diffraction studies ..................... 488
3.4. X-ray standing wave studies of the electrical
double layer at solid-aqueous solution interfaces
and in situ measurements of surface reactivity ..... 496
3.5. Effect of organic coatings and microbial biofilms
on metal oxide surface reactivity - X-ray
standing wave studies of metal ion partitioning
between coating and surface ........................ 499
4. Conclusions ............................................. 504
Index ......................................................... 511
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