A molecular-beam study of methane dissociative adsorption on oxygen-precovered Pt{110}(1 x 2)

Molecular beam techniques have been used to determine the effect of oxygen adatoms on the dissociative adsorption of CH4 at a surface temperature of 400 K. The initial sticking probability, s(0), is always smaller than that for the clean surface in the energy range studied, 90 meV less than or equal to E-t less than or equal to 500 meV and at oxygen precoverages up to one monlayer. As the interval energy of the incident CH, is increased, s(0) for the clean and oxygen-precovered surfaces converges; oxygen blocks fewer surface sites to methane dissociative adsorption. Carbon adatoms, formed from the dissociative adsorption of CH4, react readily with O-a to form CO. (C) 2000 Elsevier Science B.V. All rights reserved.