The nature of activation of methane on supported nickel catalyst has been investigated by means of temperature programmed surface reaction (TPSR), temperature programmed desorption (TPD), X-ray photoelectron energy spectroscopy (XPS) and pulse reaction and a synergetic mechanism of carbon dioxide reforming with methane is tentatively postulated. TPSR, TPD and XPS results indicate that carbidic Cα, carbonaceous Cβ and carbidic clusters Cγ surface carbon species formed by decomposition of methane show different surface mobility, thermal stability and reactivity. Cα and Cβ species on the nickel surface are thermally unstable and can be rapidly converted into Cγ species upon increasing temperature. The carbidic carbon is a very active and important intermediate in carbon dioxide reforming with methane and the carbidic clusters Cγ species might be the precursor of the surface carbon deposition.
