DFT investigations for the catalytic reaction mechanism of methane combustion occurring on Pd(ii)/Al-MCM-41

Abstract

In this work, a theoretical analysis was carried out on the mechanism of methane combustion occurring on single site palladium oxide species [Pd]²⁺ supported on Al-MCM-41 silica. Single site Pd-oxo and PdO₂-superoxo structures were used to represent the active centers. Activation energies for all the elementary steps involved in the oxidation of methane into formaldehyde are presented. The competition of methane/methanol substrates on active sites was examined. It was found that the formation of methanol via the reaction of methane with the superoxo species, formed via the adsorption of O₂ on reduced Pd(II) centers, facilitates the production of the very active Pd-oxo catalytic sites.