Fundamentals of Electrochemistry
Transcript of Fundamentals of Electrochemistry
Fundamentals of Electrochemistry V. S. Bagotzky A. N. Frumkin Institute of Electrochemistry Russian Academy of Sciences Moscow, Russia
Translated from Russian by Klaus Müller
Plenum Press • New York and London
CONTENTS
Part 1. Basic Concepts
Chapter 1. Electric Current in Galvanic Cells. The Electrodes 3
1.1. Free Charges in Conductors 3 1.2. Electric Current in Conductors 5 1.3. Brief Characterization of the Different Kinds
ofConductor 8 1.4. Circuits Involving Galvanic Cells 15 1.5. Electrodes and Electrode Reactions 17 1.6. Faraday's Laws 24 1.7. Mass Transport in Electrolytes 25 1.8. The Sign Convention for the Current and the Fluxes . . . . 26
Chapter 2. Electrode Potentials 29 2.1. Electrostatic Fields and Potentials 29 2.2. Interfacial Potential Differences (Galvani Potentials) . . . . 33 2.3. Open-Circuit Voltages 37 2.4. Defining the Concept of "Electrode Potential" 41 2.5. Nonequilibrium Electrode Potentials 44 2.6. Potentials at the Conductor/Insulator (or Vacuum)
Interphase 47
Chapter 3. Thermodynamics of Electrochemical Systems . . . 53 3.1. Ways to Describe Compositum 53 3.2. Conventional and Undefined Parameters 54 3.3. Thermodynamic Functions in Electrochemistry 55 3.4. Thermodynamic Activity 60
xiii
xiv CONTENTS
3.5. Equations for the emf of Galvanic Cells 63 3.6. Concentration Dependence of Electrode Potentials 66 3.7. Special Thermodynamic Features of Electrode Potentials . . 72
Chapter 4. Diffusion Processes in Electrochemistry 81 4.1. Basic Laws oflonic Diffusion in Solutions 81 4.2. Diffusion During Current Flow in Electrolytes 85 4.3. Ionic Transport by Migration and Diffusion 88 4.4. Convective Transport 94
Chapter 5. Phase Boundaries (Interfaces) between Electrolytes 105
5.1. Types of Interfaces between Electrolytes 105 5.2. Diffusion Potentials 107 5.3. Distribution of the Ions between Dissimilar Electrolytes . . . 112 5.4. Distribution of Ions in Cells with Membrane 115 5.5. Galvanic Cells with Transference 117
Chapter 6. Polarization of Electrodes 121 6.1. Basic Concepts 121 6.2. The Laws of Activation Polarization 125 6.3. Diffusional Concentration Polarization 135 6.4. Superposition of Concentration and Activation
Polarization 140
Chapter 7. Transient Processes 147 7.1. Evidence forTransient Conditions 147 7.2. Transient Diffusion to Electrodes of Large Size 149 7.3. Transient Diffusion to Electrodes of Finite Size 155
Chapter 8. Types of Electrodes Used 157 8.1. Nonconsumable Electrodes . 158 8.2. Reacting Electrodes 160 8.3. Reference Electrodes 161
Chapter 9. Electrochemical Research Techniques 167 9.1. Voltage and Electrode Potential Measurements
(Potentiometry) . . . 170 9.2. Steady-State Polarization Measurements 170 9.3. Transient (Pulse) Measurements 174
CONTENTS xv
9.4. Alternating-Current Measurements 184 9.5. Polarography 193
Part 2. Properties of Electrolytes and Interfaces
Chapter 10. Aqueous Electrolyte Solutions 203 10.1. The Properties and Structure of Water 203 10.2. Thermodynamic Properties of Solutions 206 10.3. Electrolytic Dissociation 208 10.4. Conductivity of Electrolyte Solutions 214 10.5. Ionic Transport Numbers 221 10.6. Ionic Solvation (Hydration) in Solutions 227 10.7. Activity of Real Electrolyte Solutions 236 10.8. Physical Theories of Ion-Ion Interactions 243 10.9. Ionic Reactions and Equilibria 258
Chapter 11. Polyelectrolytes and Nonaqueous Electrolytes 267
11.1. Polyelectrolytes 267 11.2. Nonaqueous Electrolyte Solutions 269 11.3. Ionically Conducting Melts 273 11.4. Solid Electrolytes 278
Chapter 12. Structure and Properties of Surface Layers . . . 283 12.1. General Concepts 283 12.2. Adsorption 287 12.3. Excess Surface Energy. Wetting 292 12.4. Thermodynamics of Surface Phenomena 294 12.5. Structure of the Electric Double Layer 299 12.6. Methods for Studying Electrode Surfaces 311 12.7. The Mercury Electrode Surface 316 12.8. The Platinum Electrode Surface 320 12.9. Surfaces of Other Electrodes 330 12.10. Two Problems in Electrochemistry 334
Part 3. Electrochemical Kinetics
Glfapter 13. Multistep Electrode Reactions 339
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13.1. Intermediate Reaction Steps 339 13.2. Rate-Determining Step 341 13.3. Two-Step Electrochemical Reactions 343 13.4. Complex Electrochemical Reactions 349 13.5. Reactions with Homogeneous Chemical Steps 351 13.6. Reactions with Mediators 355 13.7. Parallel Electrode Reactions 357
Chapter 14. The Elementary Reaction Act 361 14.1. The Energy of Activation 361 14.2. Kinetic Influence of the Electric Double Layer 369 14.3. Kinetic Infiuence of Adsorption 371 14.4. Infiuence of the Electrode Material 374
Chapter 15. Reactions Producing a New Phase 385 15.1. Intermediate Stages in the Formation of New Phases . . . . 385 15.2. Formation of Gas Bubbles 387 15.3. Crystal Phase Formation (Metal Deposition) 392
Part 4. Scientific Principles of Applied Electrochemistry
Chapter 16. Main Areas of Applied Electrochemisty 397
Chapter 17. Electrochemical Reactors 409 17.1. Design Principles 409 17.2. Separators 414 17.3. Macrokinetics of Electrochemical Processes 418
Chapter 18. Reactions Involving Metals or Other Solids . . . 427 18.1. Reacting Metal Electrodes 427 18.2. Anodic Metal Dissolution 429 18.3. Surface-Layer Formation 432 18.4. Passivation of Electrodes 437 18.5. Corrosion of Metals 443 18.6. Electrochemical Metal Treatments 451 18.7. Cathodic Metal Deposition 454 18.8. Reacting Nonmetal Electrodes 460
Chapter 19. Reactions at Nonconsumable Electrodes 465
CONTENTS xvii
19.1. Hydrogen Evolution and Ionization 465 19.2. Reactions Involving Oxygen 476 19.3. Reactions Involving Chlorine and Other Halogens 483 19.4. Reactions Involving Organic Substances 486 19.5. Reactions at High Anodic Potentials 493 19.6. Electrocatalysis 497
Chapter 20. Electrochemical Methods of Analysis 499 20.1. Conductometry 500 20.2. Coulometry 501 20.3. Voltammetry 503 20.4. Potentiometry 510
Chapter 21. Photoelectrochemistry 519 21.1. Energy Levels of Electrons in Electrodes and
in the Electrolyte 521 21.2. Electron Photoemission into Solutions 526 21.3. Photoexcitation of Semiconductor Electrodes 529 21.4. Photoexcitation of Reacting Species 536
Chapter 22. Electrokinetic Processes 539 22.1. Electrokinetic Potential 542 22.2. Basic Equations of Electrokinetic Processes 546 22.3. Practical Use of Electrokinetic Processes 551
Chapter 23. Bioelectrochemistry 553 23.1. Transmission of the Nervous Impulse 554 23.2. Bioenergetics 566 23.3. Electrochemical Methods in Biology and Medicine . . . . 572
Bibliography 579
Author Index 583
Subject Index 585