DENSITY FUNCTIONAL THEORY INVESTIGATIONS INTO METHANE ACTIVATION, OXIDATION, AND DIFFUSION ON IrO2(110), RuO2(110), AND MIXED METAL OXIDE MO2(110) (M=Ir & Ru)

Abstract

The processes of methane adsorption and oxidation over late transition metal oxides of rutile type, as well as the adsorption and ensuing interaction of probabilistic species with the intermediate products of methane oxidation on the surfaces of iridium dioxide and ruthenium dioxide, and their various combinations, have been comprehensively examined utilizing the principles of density functional theory (DFT). Density functional theory calculations serve as a critical tool in this study, elucidating the stability of these mixed metal oxides, the energy dynamics of the corresponding reaction pathways, and the diffusion properties potentially influencing bifunctional reaction mechanisms. Further, DFT was employed to calculate reaction and activation-free energies pertinent to the methane reaction pathways on surfaces of IrO2(110) and mixed oxides. These computations provide valuable insights into the reaction mechanisms, critical structural properties, and the capacity of these pathways to function under steady-state catalytic conditions. This enhanced understanding permits the identification and mapping of the potential mechanisms that drive these reactions, contributing significantly to the body of knowledge on the structural properties that could determine the viability of these pathways under continuous catalytic conditions.