Dynamics of gas–surface interactions: Reaction of atomic oxygen with adsorbed carbon on platinum

Abstract

Stochastic classical trajectory studies have been carried out of the Rideal‐type reaction of gas‐phase oxygen atoms with carbon adsorbed on the (111) face of a platinum crystal. Flow of energy between the reaction zone and the crystal has been incorporated in an accurate way. An empirical interaction potential has been employed, based on experimental information about gas‐phase CO and about C, O, and CO adsorbed on platinum. Although the interaction potential is uncertain, the major qualitative conclusion of the study—that the product CO molecule escapes quickly from the surface with considerable internal excitation—is unaffected by substantial alterations of the potential. Rotational angular momentum is predicted to be anisotropic, and product angular distributions peaked toward the surface normal. Mechanisms involving excitation of conduction electrons are shown to play a significant but not dominant role in removing energy from the product.