D2O product angular and translational energy distributions from the oxidation of deuterium on Pt(111)

The angular and translational energy distributions of D2O produced from the oxidation of deuterium on the (111) crystal face of platinum have been measured over the surface temperature range of 440–913 K. Although the angular distributions are described by a cosine function, the translational energy distributions deviate from the corresponding Maxwell–Boltzmann distributions. At the normal angle, the D2O mean translational energy 〈E〉/2k varies from 220 to 400 K over the temperature range investigated. Two mechanisms for the production of translationally cold product molecules are discussed.