Theoretical Investigation of Methane’s Dehydrogen-Reforming with Supercritical Carbon Dioxide over Transition Metals (Pt,Rh,Ru)

A mechanism of the dehydrogen-reforming of methane with carbon dioxide over Pt, Rh and Ru under a supercritical condition was investigated by B3LYP/Lanl2dz and MP2 methods. Results show that the reforming reaction divided into six steps under the supercritical state, the rate-determining steps of the reaction over the different transition metals were not the same. Dehydrogenation plays a significant role pin the process of reforming reaction. For Pt, Rh and Ru, the easiest step is the same-step 1. All of the other steps were exothermic reactions. The process of reaction over Pt, Rh and Ru were similar with the reaction over Ni. For Pt, the CO2 Specific activities of four kinds of the transition metals were in the order: Pt>Rh>Ru.