Adsorption dynamics of CO on Cu(110): a molecular beam study

Molecular beam measurements of initial adsorption probabilities, So, as wel l as the coverage dependence of the adsorption probability, S(Theta), of CO on Cu(1 1 0) are presented. The influence of kinetic energy, polar impact angle, ai, azimuthal orientation ([100] and [110]), and adsorption temperat ure, T-s, on the adsorption dynamics have been studied. With regard to micr okinetical models used to describe processes in heterogeneous catalysis, th e dependence of the adsorption probability on the density of defects has be en investigated. The surface has been characterized by measuring He atom an gular distributions, He atom reflectivity curves, and LEED. The shape of th e S(Theta) curves are consistent with a precursor mediated adsorption mecha nism. For low temperatures T(s)less than or equal to 90 K, the adsorption d ynamics are dominated by adsorbate assisted adsorption. Despite the pronoun ced difference in the surface corrugation along the different high-symmetry directions no significant differences in S-0 and S(Theta) were observed fo r the different azimuths studied. (C) 2001 Elsevier Science B.V. All rights reserved.