Techniques and Mechanisms in Electrochemistry

Techniques and Mechanisms in Electrochemistry P.A. Christensenand A. Hamnett Department of Chemistry University of Newcastle upon Tyne

Kluwer Academic Publishers 1994

Page iv

Published By Blackie Academic & Professional, An Imprint Of Chapman & Hall, Wester Cleddens Road, Bishopbriggs, Glasgow G64 2NZ Chapman & Hall, 2-6 Boundary Row, London SE1 8HN, UK Blackie Academic & Professional, Wester Cleddens Road, Bishopbriggs, Glasgow G64 2NZ, UK Chapman & Hall Inc., One Penn Plaza, 41st Floor, New York NY 10119, USA Chapman & Hall Japan, Thomson Publishing Japan, Hirakawacho Nemoto Building, 6F, 1-7-11 Hirakawa-cho, Chiyoda-ku, Tokyo 102, Japan DA Book (Aust.) Pty Ltd., 648 Whitehorse Road, Mitcham 3132, Victoria, Australia Chapman & Hall India, R. Seshadri, 32 Second Main Road, CIT East, Madras 600035, India First edition 1994 © 1994 Chapman & Hall Typeset in 10/12pt Times New Roman by Thomson Press (India) Ltd., New Delhi Printed in Great Britain at the Alden Press, Oxford ISBN 0 7514 0129 3 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers at the Glasgow address printed on this page. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication data Christensen, P.A., 1960– Techniques and mechanisms in electrochemistry / P.A. Christensen and A. Hamnett. -- 1st ed. p. cm. Includes bibliographical references and index. ISBN 0-7514-0129-3 (PB : acid-free) 1. Electrochemistry. 2. Surface chemistry. I. Hamnett, A. II. Title. QD553.C59 1993 541.3'7--dc20 93-11366

Techniques and Mechanisms in Electrochemistry by Christensen, P. A.; Hamnett, A. Table of Contents Techniques and Mechanisms in Electrochemistry Preface Contents List of Symbols 1— Introduction to Modern Electrochemistry 1.1—Structure of Surfaces 1.1.1—Structure of the Solid Electrode 1.1.2—The Structure of the Electrified Interface 1.1.3—Adsorption on the Electrode Surface 1.2—Electron Transfer 1.2.1—Thermodynamic Considerations 1.2.2—Rate of Electron Transfer 1.2.3—Rate of Transport of Solution Species 1.3—Reaction Mechanisms 1.3.1—Homogeneous Electrochemical Mechanisms 1.3.2—Electrochemical Mechanisms with Adsorbed Intermediates 1.3.3—The Direct Detection of Intermediates Further Reading 2— Techniques Giving Mechanistic Information 2.1—Surface Specific Processes-In Situ Techniques 2.1.1—Electrocapillarity 2.1.2—Linear Sweep Voltammetry and Cyclic Voltammetry 2.1.3—Scanning Tunnelling Microscopy 2.1.4—Scanning Tunnelling Spectroscopy 2.1.5—Atomic Force Microscopy 2.1.6—Infrared Spectroscopy 2.1.6.1—Transmission 2.1.6.2—Internal Reflectance (Attenuated Total Reflectance ATR) 2.1.6.3—External Reflectance 2.1.6.4—Electrically Modulated Infrared Spectroscopy, (EMIRS) 2.1.6.5—Polarisation Modulation Infrared Reflection-Absorption Spectroscopy (PMIRRAS or IRRAS) 2.1.6.6—In-Situ Fourier transform Unfrared Spectroscopy 2.1.7—The Raman Spectroscopies 2.1.8—Ellipsometry 2.1.9—X-Ray Spectroscopies 2.1.9.1—X-Ray Diffraction 2.1.9.2—Surface Extended X-Ray Absorption Fine Structure (SEXAFS) 2.1.9.3—Long Period X-Ray Standing Waves (XSW) 2.1.9.4—Specular X-Ray Reflection 2.1.10—AC Techniques 2.2— In Situ Probes of the Near-Electrode Region 2.2.1—Chronoamperometry, Chronocoulometry and the Butler–Volmer Equation 2.2.2—Voltammetry

2.2.3—The Controlled-Convection Techniques: The Rotating Disc and Rotating RingDisc Electrodes 2.2.4—Electron Paramagnetic Resonance 2.2.4.1—The g-factor 2.2.4.2—Hyperfine Splitting 2.2.5—UV-Visible Spectroelectrochemistry 2.2.6—The Electrochemical Quartz Crystal Microbalance 2.2.7—FTIR and Related Techniques 2.2.7.1—Transmittance 2.2.7.2—External Reflectance 2.2.8—Mass Spectrometry Techniques – DEMS 2.3—Ex Situ Emersion Techniques 2.3.1—Structural and Analytical Methods 2.3.2—Mass Spectrometric Techniques References Further Reading 3— Examples of the Application of Electrochemical Methods 3.1— The Cyclic Voltammogram of Platinum in Acid Solution 3.1.1—The Hydride Region 3.1.2—The Oxide Region 3.1.3—The Voltammetry of Single-Crystal Platinum Electrodes 3.2—The Electro-Oxidation of Methanol at Platinum in Acid Solution 3.2.1—Methanol Oxidation at a Smooth Polished Polycrystalline Platinum Electrode 3.3—The Electrochemical Reduction of CO[sub(2)] 3.3.1—The Direct Reduction of CO[sub(2)] in Non-Aqueous Solvents 3.3.2—The Catalysed Reduction of CO[sub(2)] 3.4—Reactive Film Formation on Electrodes 3.4.1—Oxide Formation on Metals: The Nature of the Passive Film on Iron 3.4.2—Conducting Polymers 3.3.2.1—Structure 3.3.2.2—Static Measurements 3.3.2.3—Dynamic Properties 3.5—Adsorbed Films for the Promotion of Enzyme Electrochemistry References Further Reading Index