Kinetic model for dissociative adsorption of a diatomic gas

Abstract

A general kinetic formulation is given for the adsorption, desorption, and skating of adatoms formed by the dissociative adsorption of a diatom onto a general, two‐dimensional lattice. This formulation is then specialized to include only irreversible adsorption without skating or desorption. This problem is solved exactly for the linear array and is solved by successive approximations for primitive lattices of three, four, and sixfold symmetry. For practical purposes, results, which are in satisfactory agreement with limiting results, could be obtained by an analysis limited to the first and second shells of sites around a given site. Limiting fractional surface coverages, which are due to isolated, empty sites surrounded by filled sites, are given for all lattices. Results agree well with Monte Carlo experiments on square lattices. Results for irreversible adsorption without skating are readily adaptable to the problem of irreversible desorption without skating.