Internal states distributions of NO thermally desorbed from Pt(111): Dependence on coverage and co-adsorbed CO

Abstract

The distribution of population in the internal energy levels of nitric oxide thermally desorbed from Pt(111) has been probed using laser excited fluorescence. The observed rotational distributions have been found to follow the Boltzmann distribution function, independent of NO coverage or the presence of pre- or post-adsorbed CO. Under all conditions of NO desorption, the observed NO was characterized by a temperature (0.95±0.05) times the surface temperature. No evidence of a preferred alignment of the rotational angular momentum vectors was observed, nor was there any difference between the two spin-orbit multiplets beyond that associated with the rotational temperature.