Methane activation on clean and oxidized Ni(100)

The activation of methane was investigated on a clean and oxidized Ni(100) surface in the pressure range of 0.05–1.0 Torr. The results are most consistent with a precursor mediated mechanism being primarily responsible for the reactive sticking of methane on the clean Ni(100) surface. This contrasts with the Ni(111) surface where dissociative adsorption has been determined to occur predominantly through the direct mechanism. The reaction probability of methane on the NiO films was significantly lower than that observed for the clean Ni(100) surface and exhibited an apparent activation energy of 8.8±1.1 kcal/mol. The results suggest that methane activation on NiO occurs on defect metallic nickel sites.