Various equations for the kinetics of chemisorption derived from a common model

Abstract

The assumptions used in previous work (J. Chem. Soc., Faraday Trans. 1, 1977, 73, 456 and 1943) are applied to the case in which the surface or any patches on the surface attain high coverages. New equations for the non-Elovichian parts of the isotherm are derived. In the pre-Elovichian range at the beginning of the process dq/d ln t increases with t, at first proportionally to a fractional power of t and later proportionally to the logarithm of t(q is the amount adsorbed and t the time). In the post-Elovichian range at the end of the process dq/d ln t decreases with t, the decrease is first parabolic and later exponential. The Elovich equation with dq/d ln t constant is obeyed between these two ranges.