Methane adsorption and dissociation mechanism on the WC(001) surface: a first-principle calculation

Abstract

The conversion of methane in catalysis fields has aroused much attention for its abundant distribution in nature and it is environment-friendly. However, the C–H chemical breaking is a major challenge and requires proper catalysts for methane activation. Using first-principle calculations, we systematically explore the atomic configuration, interaction strength, dehydrogenation process and electronic properties of methane on noble metal Pt(111) and isoelectronic transition metal carbide WC(001) surface. The adsorption strength of methane activation on the WC(001) surface is stronger and the barrier of C–H bond breaking is smaller than that of the Pt(111) surface. Moreover, the oxygen concentration ranging from 40% to 60% coverage on the WC(001) surface benefits the methane activation and the energy barrier decreased to 0.26 ∼ 0.57 eV. The larger charge transfer emerges at the interface between methane and the WC(001) surface with or without oxygen coverage comparable to the Pt(111) surface. Our theoretical results can provide vital guidance for experimental synthesis conditions of methane activation and the transition metal carbide application in catalysts.