Chemical Bonds Outside Metal Surfaces

1. Background, Phenomenology, and Motivation.- 1.1. Chemisorption in Ionic and Covalent Limits.- 1.1.1. Ionic Bond Formation.- 1.1.2. Covalently Bonded Cases.- 1.2. Kinetics of Adsorption and Desorption.- 1.3. Thermodynamics of Adsorption.- 1.3.1. Langmuir Isotherm.- 1.3.2. Multilayer Adsorption Theory.- 1.4. Reaction Mechanisms Outside Surfaces.- 1.4.1. Langmuir-Hinshelwood and Rideal-Eley Mechanisms.- 1.4.2. Redhead Equation for Desorption Rate.- 1.5. Case History of Catalytic Hydrogenation of Carbon Monoxide.- 1.5.1. Thermodynamics.- 1.5.2. Chemisorption Studies of CO and H2.- 1.5.3. Selectivity.- 1.5.4. Mechanism.- 2. Diatomic Molecules.- 2.1. Physisorbed Diatoms with Weil-Defined Cores.- 2.1.1. Image Theory of the Dispersion Force.- 2.2. Interaction Between Two Hydrogen Atoms.- 2.2.1. Physisorbed H2.- 2.2.2. Protons Embedded in the Spill-Out Metal Electron Clouds.- 2.3. Interaction Energy: Tight-Binding Model.- 2.3.1. Range of Validity: Anisotropic Effects, Adatom-Substrate Coupling, and Energy-Level Matching.- 2.4. Molecular Versus Dissociative Adsorption.- 2.4.1. Pauling’s Treatment of Bond Energies.- 2.4.2. Bonding and Valence in Transition Metals.- 2.4.3. Admolecule Bonding to a Metal Surface.- 2.4.4. Chemisorption of N2, O2, CO, and NO.- 2.5. Detailed Bonding Studies.- 2.5.1. Nitrogen on Metal Surfaces.- 2.5.2. Cluster Modeling of NO on Ni.- 2.5.3. Limitations and Convergence Properties of Cluster Calculations.- 2.6. Electronically Excited States of Chemisorbed Diatoms.- 2.6.1. EELS Study of Weakly Adsorbed Systems.- 2.6.2. Summary of Assignments.- 2.7. Orientation of Molecular Adsorbates.- 2.8. Temperature Effects, and Comparison Between Theory and Experiment.- 3. Conformation and Electronic Structure of Polyatomic Molecules.- 3.1. Conformation of a Water Molecule Outside a Metal Surface.- 3.1.1. Valence Theory of Free-Space Conformation.- 3.1.2. Interaction Energy in a Water Molecule.- 3.1.3. Introduction of the Image Potential.- 3.1.4. Effect of the Surface on Hybridization.- 3.1.5. Results and Discussion.- 3.2. Conformation of NH3 and C2H4 Molecules.- 3.2.1. Interaction Between Lone Pair and Image for NH3.- 3.2.2. Adsorption of Ethylene on a Planar Metal Surface.- 3.2.3. Cluster Approach to the Electronic-Level Structure of Ethylene on Ni(100).- 3.3. Molecular Versus Dissociative Adsorption of NH3 on Transition-Metal Surfaces.- 3.4. Electronic Structure and Conformation of Ethene on Transition- and Noble-Metal Surfaces.- 3.4.1. Conformation of Ethene on Metal Surfaces.- 3.4.2. Tight-Binding Model of ?-Levels of Adsorbed Ethene.- 3.4.3. Effect of the Surface on ?-Levels.- 3.4.4. ?-Orbital Bonding and Charge Transfer Between Molecule and Metal.- 3.5. Interaction Between Adsorbates.- 3.5.1. Hydrogen-Bonded Clusters of H2O.- 3.5.2. Some Organic Molecules.- 3.6. Electronic Excited States of Chemisorbed Polyatomic Molecules.- 4. Dynamics of Adparticles and Neutron Inelastic Scattering.- 4.1. Principles of Neutron Scattering from Adsorbed Molecules.- 4.2. Comparison With Other Surface Techniques.- 4.3. Diffusion Measurements.- 4.4. Theory.- 4.4.1. Influence of Diffusion on Scattering Cross-Section.- 4.5. Electronic and Vibration-Rotation Spectra of Adsorbed Molecules.- 4.6. Adsorbate Frequency Shifts.- 4.6.1. Influence of n-Fold Coordination.- 4.6.2. Intensity in Local Mode at Adsorbate Site.- 4.7. Theoretical Framework for Interpreting Neutron Inelastic Scattering From Covered Surfaces.- 4.7.1. Description of the Model.- 4.7.2. Coupling of an Adparticle to a Two-Dimensional Square Lattice.- 4.7.3. Interpretation of Neutron Intensity for Hydrogen on Platinum.- 4.8. Theory of Surface Diffusion.- 4.9. Vibration Excitation in Molecule-Surface Collisions Due to Temporary Negative Molecular-Ion Formation.- 4.10. Adparticle Dynamics: Kramers’ Equation in a Metallic Medium.- 4.10.1. Electronic Contribution to the Surface-Friction Constant.- 4.10.2. Introduction of Inhomogeneity at a Metal Surface.- 4.10.3. Long-Range Dynamic Interaction Between Adatoms.- 5. Molecular Desorption.- 5.1. Kramers’ Theory Generalized to Desorption From Solid Surfaces.- 5.1.1. Derivation of the Rate Equation.- 5.1.2. Rate of Desorption of Atoms.- 5.1.3. Rate of Desorption of Molecules.- 5.1.4. Results: Atomic and Molecular Desorption.- 5.2. Transition-State Theory Applied to Desorption From Solid Surfaces: Ammonia on Ni(111).- 5.2.1. Rate of Molecular Desorption.- 5.3. Microscopic Theories.- 5.3.1. One-Phonon Approximation.- 5.3.2. Atom-Phonon Interaction.- 5.4. Quantum-Statistical Theory of Physisorption.- 5.4.1. Flash Desorption.- 5.4.2. Isothermal Desorption.- 5.4.3. Limitations of the Relaxation-Time Approach to Desorption.- 5.5. Coverage-Dependent Regime.- 5.5.1. Mean-Field Theory of Physisorption.- 5.5.2. Kramers’ Theory.- 5.6. Desorption Induced by Electronic Transitions.- 5.6.1. Menzel—Gomer—Redhead Model.- 5.6.2. Knotek—Feibelman Mechanism of Initial Excitation.- 5.6.3. Structural Information From Photon-Stimulated Desorption.- 5.6.4. Theory of Angle-Resolved Electron- and Photon-Stimulated Desorption.- 5.6.5. Electron-Stimulated Molecular Desorption From Metals.- 6. Catalysis.- 6.1. Some Definitions and Concepts.- 6.1.1. Specific Rate.- 6.1.2. Reaction Probability.- 6.1.3. Elementary Reaction Steps.- 6.2. XPS Studies of Desorption and Dissociation Processes.- 6.2.1. Photoelectron Spectroscopy in Relation to Heterogeneous Catalysis.- 6.3. Compensation Effect.- 6.3.1. Theoretical Basis.- 6.3.2. Compensation Temperature Tc.- 6.4. Relevance of Woodward—Hoffmann Rules to Single-Crystal Catalysts.- 6.4.1. Classification of Symmetry-Allowed or Forbidden Reactions.- 6.4.2. Symmetry-Conservation Rules.- 6.4.3. Use of a Correlation Diagram in Understanding the Activation Barrier.- 6.4.4. Can Symmetry Effects Alone Explain Nitric-Oxide Decomposition on Platinum?.- 6.5. Electronic Structure Study of a “Poisoned” Catalyst Surface…..- 6.6. Chemical Oscillations.- 6.6.1. Nature of Rate Equations.- Appendixes.- 1.1. Surface Characterization Techniques Used to Determine Structure and Composition of Solid Surfaces.- 2.1. Density Matrix and Linear-Response Function of the Infinite-Barrier Model of a Metal Surface.- 2.2. Influence of Fermi-Surface Topology on Asymptotic Displaced-Charge Round Adatoms.- 2.3. Correlation Effects for Hydrogen Chemisorbed on Transition Metals.- 2.4. Lifetimes of Excited States of Molecules Well Outside Metal Surfaces: a Model Calculation.- 3.2. Parametrization of the Tight-Binding Model of Ethene.- 3.3. Parametrization of the Anderson Hamiltonian Describing the ?-Energy Levels of the Free Ethene Molecule.- 4.1. Three-Dimensional Treatment of the Escape of a Brownian Particle From a Well.- 4.2. Dynamics of a Brownian Particle in a Fluid: Derivation of Stochastic Elements.- 4.3. Variational Principle for the Optimum Reaction Coordinate in Diffusion-Controlled Reactions.- 4.4. Anisotropic Screening of an Adatom Near a Metal Surface.- 5.1. Spin Fluctuations and Desorption of Hydrogen From Paramagnetic Metals.- 5.2. Anomalies in Adsorption Equilibrium Near Critical Points of a Substrate.- 6.1. Symmetry Rules Based on the Surface Electronic Structure of Various Platinum Surfaces.- 6.3. Analysis of Rate Equations Describing Chemical Oscillations.- 6.4. Proposed Reaction Sequence for Fischer-Tropsch Synthesis.- 6.5. Dissociative Chemisorption — A Primitive Surface Chemical Process.- 6.6. Nonlinear Rate Equations and the Compensation Effect.- Notes Added in Proof.- References.