COMPARISON OF MODELS IN HETEROGENEOUS CATALYSIS FOR IDEAL AND NON-IDEAL SURFACES

A generalized multicomponent adsorption isotherm is used to derive rate equations for kinetic models which, from an energetic point of view, assume adsorption sites that are: (a) all identical (Langmuir), (b) have a linear distribution of adsorption energies (Temkin), or (c) have a logarithmic distribution of adsorption energies (Freundlich). A comparison is then made of the goodness of fit, for each of these rate equations, for 19 studies reported in the literature in which detailed kinetic data are available. In general, the same level of fitting is obtained for all three isotherm equations, indicating that the effect of distribution of site energies on the global kinetics is weak.