Tailoring Oxygen Vacancies in LaBO3 Perovskites via Doping for Methane Oxidation

Abstract

In perovskite oxides, a lower formation energy of oxygen vacancies leads to higher lattice oxygen activity and enhanced oxidation capability. However, high oxygen activity usually requires dense intrinsic vacancies, compromising structural stability. Herein, we propose a design strategy of anchoring a metal atom M on perovskite oxides, enabling efficient lattice oxygen activation while preserving the perovskite framework. Using density functional theory calculations, we systematically investigate a series of M/LaBO3 (M = Co, Pd, Pt, Ir, etc.; B = Ti, Cu, V, Al, Ru, etc.). The adsorbed atoms activate oxygen species, either by promoting dissociation of oxygen molecules or by activating lattice oxygen atoms, which arise from the electron donation between the M and LaBO3 surface. These interactions facilitate lattice oxygen activation and significantly lower the rate-determining step barrier for methane oxidation. Our findings offer a new strategy to tailor oxygen vacancies in perovskite oxides via doping for methane oxidation.