Photoinduced dissociation and desorption of nitrous oxide on a platinum(111) surface

N{sub 2}O adsorbed on a Pt(111) surface was irradiated by UV light from a mercury arc lamp. The photochemistry of N{sub 2}O was studied by XPS, UPS, and TPD. Upon irradiation at 50 K, adsorbed N{sub 2}O undergoes dissociation and desorption. Photon energies exceeding 4.35 eV are required. The cross section is in the range of 10{sup {minus}19}{minus}10{sup {minus}20} cm{sup 2}. The data are adequately described with a model involving subvacuum hot electrons.