Plasma-induced construction of defect-enriched perovskite oxides for catalytic methane combustion

Abstract

Perovskite oxides have been considered as appropriate alternatives to precious metal catalysts in CH₄ combustion due to their excellent activity and sintering-resistance capacity. Herein, an innovative plasma-induced strategy was employed to the one-step preparation of porous LaMnO₃ (LMO-P) and cerium-substituted LaMnO₃ (LCMO-P) perovskite oxides with enhanced lattice distortion. The increased specific surface area provided numerous active sites for surface diffusion, and formational lattice distortion introduced more active oxygen species. Exceptionally, the defect-enriched porous LMO-P and LCMO-P catalysts displayed supreme low temperature CH₄ oxidation activities, giving T₉₀ of 475 °C and 440 °C at a space velocity of 30 000 mL g⁻¹ h⁻¹, respectively. The excellent catalytic activities of plasma-induced perovskite catalysts might be associated with high reactivity of oxygen adspecies as well as preferable reducibility. This study will provide a novel and universal strategy for the synthesis of composite oxide catalysts with rich surface defects.