Underpotential Deposition (eBook)

Oscar A. Oviedo is Assistant Professor in Physico-Chemical Research Institute of Córdoba (INFIQC-CONICET) at the University of Córdoba, Argentina. His research areas are theoretical electrochemistry, electrocatalysis and in computer developments in physical chemistry.Luis Reinaudi works as a Professor at the National University of Córdoba (Argentina), and as a Researcher at Physico-Chemical Research Institute of Córdoba (INFIQC-CONICET). His fields of interest are  the study of metallic nanostructures (such as nanoparticles and nanowires), their formation, and their thermal and electrochemical stability, and include renewable energies (particularly the study of fuel cells and lithium batteries), and computer simulations of complex and non-linear systems.Silvana G. García is Professor of Chemical Engineering since 2005 at the Universidad Nacional del Sur, Bahía Blanca (Argentina). Her working areas are mainly the electrochemical formation of metallic thin films and nanostructures (nanoparticles, nanowires), involving the nucleation and growth mechanisms, and the analysis of the electrocatalytic effect of such structures for reactions of technological interest.Ezequiel Leiva is Professor at the National University of Córdoba, Argentina, and Principal Researcher of CONICET, at the Physico-Chemical Research Institute of Córdoba (INFIQC). His main interest is in theoretical aspects of electrochemistry. In recent times, he devoted considerable effort to extend the concept of underpotential deposition to the nanoscale, using nanothermodynamics, statistical mechanics and Monte Carlo simulations. Several of these new concepts are embodied in the present book.

Preface of Editor 6
Techniques and Abbreviations 8
Contents 10
Chapter 1: Introduction 14
1.1 Underpotential Deposition: A Successful Misnomer? 14
1.2 The Magic World of Metal Underpotential Deposition 15
1.3 Pre-history and Rise of upd 22
1.4 Upd Under the Loupe: Then and Now 25
References 26
Chapter 2: Experimental Techniques and Structure of the Underpotential Deposition Phase 29
2.1 Introduction 29
2.2 Cyclic Voltammetry 30
2.3 Radiotracer Methods 35
2.4 Potential Step 38
2.5 Equilibrium-Coverage-Potential Isotherms 40
2.6 Twin-Electrode Thin-Layer 41
2.7 Rotating Ring Disk Electrode 45
2.8 Electrochemical Quartz Crystal Microbalance 49
2.9 Scanning Probe Microscopy 52
2.9.1 Scanning Tunneling Microscopy 52
2.9.2 Atomic Force Microscopy 59
2.10 Low-Energy Electron Diffraction, X-Ray Photoelectron Spectroscopy and Auger Electron Spectroscopy 61
2.11 X-Ray Absorption Fine Structure 64
2.12 In-Situ Surface Differential X-Ray Diffraction 65
2.13 Transmission X-Ray Surface Differential Diffraction 66
2.14 In-Situ Surface X-Ray Scattering 67
2.15 Grazing Incidence X-Ray Diffraction 67
2.16 In Situ Infrared Spectroscopy 70
2.17 Fourier Transform Infrared Spectroscopy 70
2.18 Differential Reflectance Spectroscopy 72
2.19 Optical Second Harmonic Generation 73
2.20 Surface-Enhanced Raman Spectroscopy 74
2.21 Techniques Suited to Study Alloy Formation During the upd Process 77
2.22 In-Situ Measurement of Surface and Growth Stress 80
2.23 Applications of upd as a Tool 81
2.24 Photoacoustic Technique 84
2.25 Electrochemical Impedance Spectroscopy 85
2.26 Thermal Desorption Spectroscopy 87
2.27 Glow Discharge Optical Emission Spectroscopy 89
2.28 Underpotential Deposition in Nuclear Chemistry 91
References 95
Chapter 3: Phenomenology and Thermodynamics of Underpotential Deposition 102
3.1 Phenomenology and a First Thermodynamic Approach to Underpotential Deposition 102
3.2 Introducing the Influence of Solvent in Underpotential Deposition Modeling 107
3.3 Underpotential Deposition on Single Crystal Surfaces 108
3.4 Nernstian-like Formalisms: Underpotential Deposition in the Framework of the Electrosoption Valency 111
3.4.1 Electrical Double Layer Effects 113
3.4.2 Solvent Effects 113
3.4.3 Determination of the Electrosorption Valency 117
3.4.3.1 From Capacity and Surface Tension 117
3.4.3.2 From Coverage and Charge Flow 118
3.4.3.3 From Coverage Measurements at Difference Concentration of Active Electrolyte 118
3.4.3.4 From Kinetic Measurements 119
3.5 Thermodynamics of Underpotential Deposition Using the Formalism of Ideal Polarizable Electrodes 120
3.5.1 Formalism 120
3.5.2 Application to Sulfate Coadsorption in the Case of Cu Underpotential Deposition on Au(111) 122
3.6 Coverage Isotherms and Phase Transitions 127
3.7 A Thermodynamic Formulation Oriented to Theoretical Modeling of Underpotential Deposition as a Phase Transition, Including... 157
References 167
Chapter 4: Applications of Underpotential Deposition on Bulk Electrodes as a Model System for Electrocatalysis 173
4.1 Introduction 173
4.2 Catalysis of the Electrooxidation of Some C1 Molecules on Pure Pt Surfaces and Bimetallic Catalysis 174
4.2.1 CO 174
4.2.2 CH3OH 182
4.2.3 HCOOH 190
4.2.4 The Oxygen Reduction Reaction 197
4.2.5 Hydrogen Evolution Reaction 199
4.2.6 Nitrate Reduction Reaction 203
References 204
Chapter 5: Modelling of Underpotential Deposition on Bulk Electrodes 208
5.1 Introduction 208
5.2 Application of Quantum Mechanical Methods to Underpotential Deposition 213
5.2.1 Quantum Mechanical Modeling of Underpotential Deposition Previous to the Application of Density Functional Theory 213
5.2.2 Early Applications of Density Functional Theory to Underpotential Deposition 215
5.2.3 Density Functional Theory Calculations for Underpotential Deposition Systems 218
5.2.4 Relationship Between Excess Binding Energy and Surface Energy 222
5.2.5 Density Function Theory Calculations for Expanded Monolayers 224
5.2.6 Analysis of Substrate and Adsorbate Interaction Energy 226
5.2.7 Growth of Deposits Underpotentially formed on Stepped Surfaces 227
5.3 A Statistical-Mechanical Approach to Underpotential Deposition 229
5.4 Monte Carlo Methods 235
5.4.1 Introduction and Generalities 235
5.4.2 Off-Lattice Monte Carlo 237
5.4.2.1 Off-Lattice Monte Carlo: Applications to Underpotential Deposition 238
5.4.3 Lattice Monte Carlo 245
5.4.3.1 Simulation of Relatively Simple Underpotential Deposition Systems 246
5.4.3.2 Simulation of Cu Underpotential Deposition on Au(111) in Sulfate-Containing Electrolytes 252
5.4.4 Kinetic Monte Carlo Applications 256
5.4.4.1 Introduction 256
5.4.4.2 Electrochemical Phase Formation for an Ideal Frank-van der Merwe System 259
Model for the Substrate 260
Interactions Between the Particles of the System 260
Dynamic Hierarchy: Calculations of Rates for the Different Events 261
5.4.4.3 Other Simple Metal Deposition Systems Involving a Foreign Substrate 264
5.4.4.4 Kinetic Monte Carlo Analysis of Cu Underpotential Deposition on Au(111) 267
5.5 Miscellaneous Models Applied to Underpotential Deposition 272
5.5.1 Quantum Mechanical Semiempirical Calculations 272
5.5.2 Orientational Ordering of Adsorbed Monolayers 273
5.5.3 Entropic Contribution to Underpotential Deposition Shift: Lattice Dynamics Analysis 275
5.5.4 Application of Molecular Dynamics and Related Techniques to Underpotential Deposition 277
References 283
Chapter 6: Underpotential Deposition and Related Phenomena at the Nanoscale: Theory and Applications 286
6.1 General Aspects 286
6.2 Kinetics and Thermodynamic Driving Force 289
6.2.1 Reduction Mechanism 289
6.2.2 Strong Versus Weak Reducing Agents 292
6.2.3 Formation Mechanism of Monoatomic Nanoparticles 293
6.2.4 Statistical Mechanic Formulation on the Stability and Metastability of Nanoparticles 299
6.2.5 Bimetallic Nanoparticles 303
6.2.6 Deposition Mechanisms at the Nanoscale 304
6.3 Towards Electrochemical Control in Synthetic Routines for Free-Standing Nanoparticles 305
6.4 Thermodynamics of Underpotential Deposition at the Nanoscale 310
6.5 Atomistic Model for Underpotential Deposition on Nanoparticles 316
6.6 Strengthening and Weakening of Underpotential Deposition at the Nanoscale. Underpotential Deposition-Overpotential Deposit... 318
6.7 Experimental Research 322
6.7.1 Seed-Mediated Growth 322
6.7.2 Shape Control of Nanoparticles Synthesis by Underpotential Deposition 326
6.7.3 Galvanic Replacement and Underpotential Deposition 327
6.7.4 Hollow Nanoparticles Through Galvanic Replacement 331
6.7.5 Nanoparticles Growth Inside Dendrimers 334
References 340
Chapter 7: What Is Coming Next? 344
7.1 Underpotential Deposition as a Precision Design Tool 344
7.2 Towards an Accurate and First-Principles Modeling of Metal Underpotential Deposition/Dissolution 347
7.3 Computer Experiments 349
7.4 Curvature Effects in Underpotential Deposition at the Nanoscale 350
7.5 Role of Protective Molecules in Underpotential Deposition 350
7.6 New Models of Nucleation and Growth at the Nanoscale 352
7.7 Underpotential Deposition Voltammograms: What About the Spikes? 354
7.8 The Puzzling Occurrence of Low-Density Structures and the Need to Improve the Underpotential Deposition Modeling to Consid... 355
References 356
About the Authors 358
About the Editor 361
Index 362