Catalytic oxidation mechanism of methane via transition metals Pt, Pd and Ag

Abstract

The mechanisms for catalytic oxidation of methane via transition metals Pd, Pt and Ag in gas phase have been theoretically investigated using density functional theory (DFT). The results reveal similar pathways of C-H activation via Pd, Pt with the formation of atom-molecule complex, transition state and product. Catalytic oxidation using Pd and Pt exhibited different reaction energies. The possible pathway of C-H activation via Ag has been proposed. First, the abstraction of H from CH₄ by Ag occurs followed by the dissociation of CH₃ and AgH. With the calculation of energy parameters and rate constants, the order of catalytic performance of the three transition metals has been found to be Pt>Pd>Ag. A theoretical foundation for the catalytic oxidation of methane by single active atoms has been established.