Different CO2 collimation on stepped Pt(): a comparison of NO(a)+CO(a) and O(a)+CO(a) reactions

Abstract The collimation of the desorbing product CO 2 is very different in the NO(a) + CO(a) and O(a) + CO(a) reactions on Pt (1 1 2)=[( S )3(1 1 1)×(0 0 1)] . In the NO(a) + CO(a) reaction, CO 2 desorption collimated along the local normal of the (0 0 1) facets, whereas in the O(a) + CO(a) reaction, it sharply collimated close to the (1 1 1) terrace normal. This site switching is explained by different rate-determining steps.