Principles of Heterogeneous Catalysis

Reactions at Solid Surfaces. By Gerhard Ertl Copyright 2009 John Wiley Sons, Inc. 

FIGURE 5.1. The principle of heterogeneous catalysis. (See color insert.) 

The use of single-crystal surfaces under ultrahigh vacuum conditions as model systems will necessarily differ substantially from the conditions of real catalysis. These materials and pressure gaps can be bridged along various ways  

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W. J. Thomas and J. M. Thomas, Introduction to the Principles of Heterogeneous Catalysis, Academic Press, New York, 1967. 

Thomas JM, Thomas WJ (1967) Introduction to the principles of heterogeneous catalysis. Academic, London-New York... 

In this chapter, the basic principles of heterogeneous catalysis and surface reactions, and chemical, sustainable energy, and pollution abatement applications of heterogeneous catalysts are described [3-5],... 

Although industrial application is a major incentive for studying transition metal/zeolite systems, a second motivation is their importance for understanding fundamental principles of heterogeneous catalysis. Two key issues should be mentioned zeolite-imposed stereoselectivity and metal atom reorganization. 

When a chemical intermediate step in an overall electrochemical reaction sequence is rate determining, for example, an adsorbed radical recombination step or a first-order dissociation step involving an adsorbed intermediate [e.g., of RCOO in the Kolbe reaction (75)], then the general principles of heterogeneous catalysis do apply more or less in the usual way. However, even then, at an electrode, it must be noted that its surface is populated also and ubiquitously by oriented adsorbed solvent molecules (2, i) and by anions or cations of the electrolyte (7). The concentrations and orientational states of these species are normally dependent on electrode potential or interfacial field (7-i). 

See also J. M. Thomas and W. J. Thomas, in Introduction to the Principles of Heterogeneous Catalysis, pp. 458-459, Academic Press Inc., New York, 1967, for rate equations assembled in tabular form for various controlling mechanisms for the two reactions A B and A + B C. 

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