Document Type


Date of Original Version



An analysis is given of diffusion-influenced surface reactions using models similar to those used in solution kinetics. It is shown that a pure two-dimensional model of surface reactions yields no steady state rate constant. By incorporation of adsorption and desorption processes the deficiencies in the two-dimensional results are eliminated. Expressions are derived for diffusion-controlled and diffusion-influenced rate constants for surface reactions. Expressions are also derived for the activation energies of these surface reactions. It is shown that the activation energy for diffusion-controlled reactions wiII approximately be given by the activation energy for surface diffusion. Bounding expressions are developed for the activation energy for diffusion-influenced reactions. Comparisons are made betweeen Langmuir-Hinshe1wood and Eley-Rideal mechanisms, and it is found that Langmuir-Hinshelwood mechanisms should be more important than Eley-Rideal processes for many surface reactions.

Publisher Statement

© 1983 American Institute of Physics.This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in D.L. Freeman and J.D. Doll, “The Influence of Diffusion on Surface Reaction Kinetics,” J. Chem. Phys., 78, 6002-6009 (1983). and may be found at