A judicious injection and abstraction of a hetero-dopant in a Co3O4 catalyst for efficient methane oxidation

Abstract

Precise defect engineering of metal oxide catalysts holds great importance for improving catalytic oxidation reactions. In this work, a judicious strategy by doping and partially de-doping of Cr atoms was orchestrated to produce a defect-containing Co₃O₄ catalyst. The co-existence of the remaining Cr dopant and some metal vacancies could synergistically contribute to the distortion of the crystal structure, Co–O bond activation, generation of abundant active oxygen species and enhancement of oxygen reactivity. Consequently, the catalytic performance for the methane oxidation reaction was significantly boosted, with a methane conversion rate normalized by the specific surface area of 0.114 μmol m⁻² s⁻¹, 1.41 times that of the pure Co₃O₄ catalyst at a reaction temperature of 295 °C. This work provides a viable methodology for improving Co₃O₄ catalysts for efficient methane oxidation.