ADVANCES IN CATALYSIS AND RELATED SUBJECTS VOLUME 21 EDITED BY D. D. ELEY HERMAN PINES The University Nottingham, England Northwestern University Evanston, Illinois PAULB. WEISZ Mobil Research and Development Corporation Princeton, New Jersey CURRENT ADVISORY BOARD M. BOUDART Stanford, California P. H. EMMETT Baltimore, Maryland G. NATTA Milan, Italy M. CALVIN Berkeley, California J. HORIUTI Sapporo, Japan E. K. RIDEAL London, England J. H. DE BOER Delft, The Netherlands W. JOST Gottingen, Germany P. W. SELWOOD Santa Barbara, California H. S. TAYLOR Princeton, New Jersey 1970 ACADEMIC PRESS, NEW YORK AND LONDON Contributors Numbers in parentheses indicate the pages on which authors’ contributions begin. C. AHARONI,* Department of Chemistry, Imperial College of Science and Technology, London, England (1) R. R. FORD,Physics Department and Surface Studies Laboratory, University of Wzsconsin at Milwaukee, Milwaukee, Wisconsin (51) JOHN W. MAY, Bartol Research Foundation of the Franklin Institute, Swarthmore, Pennsylvania ( 15 1) L. RIEKERT,~ Mobil Oil Corporation Princeton, New Jersey (281) F. C. TOMPKINS, Department of Chemistry, Imperial College of Science and Technology, London, England ( 1 ) CARLWAGNER, Max Planck Institute for Physical Chemistry, Gottingen, Germany (323) * Present address: Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa, Israel. t Present address: BASF/Ammoniaklaboratorium, 67 Ludwigshafen, Germany. vii COPYRIGHT 8 1970, BY ACADEMIC PRESS,INC. ALL RIGHTS RESERVED NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM, BY PHOTOSTAT, MICROFILM, RETRIEVAL SYSTEM, OR ANY OTHER MEANS, WITHOUT WRITTEN PERMISSION FROM THE PUBLISHERS. ACADEMIC PRESS, INC. 111 Fifth Avenue, New York,New York 10003 United Kingdom Edition published b y ACADEMIC PRESS, INC. (LONDON) LTD. Berkeley Square House, London W l X 6BA LIBRARY OF CONGRESS CATALOG CARD NUMBER:49-7755 PRINTED IN THE UNITED STATES OF AMERICA HE BIG KINETICNETWORK AN EDITORIAL PREFACE Here and there, in one form or another, we hear calls for re-evaluation of nearly every human activity and “advance.” I n keeping with the statistical nature of the human assemblage, the questioning takes all forms, from the kind to the belligerent, from the divine to the ridiculous. They all are intrinsic ingredients of the dynamics of human evolution. Yet, they all seek to alter the complex kinetics of the process of human activity to achieve better overall results. Suddenly, we find ourselves touched by a feeling of familiarity of concepts . . . . . . The concentration of living gazelles is determined by their rate of production (a function of the concentration of many reactants, the concentration of gazelles itself, etc.) and by the rate of their disappearance (a function of the concentrations of tigers, men, certain viral and bacterial species, etc.). . . . The products the gazelle creates, including itself, i t returns to the ecological box, where they in turn become reactants in the kinetic equations of other species . . . The entire network of coupled kinetic processes is endothermic with energy derived partly thermally, partly photochemically from the sun . . . transients or new reactants introduced into a steady-state kinetic network result in the modification of many species concentrations . . . many kinetic sequences, especially exothermic ones, can undergo dramatic instabilities . . . catalysts play vital roles in all rate processes . . . We are all familiar with t