Surface modification of macroporous La0.8Sr0.2CoO3 perovskite oxides integrated monolithic catalysts for improved propane oxidation

Perovskite oxides have emerged as promising alternatives for the supported Platinum group metal catalysts for total oxidation of propane and other volatile organic compounds (VOC). Here, we report a surface modification method to improve propane oxidation activity of La0.8Sr0.2CoO3 monolithic catalysts using diluted oxalic acid etching. The oxalic acid treatment decreases the light-off temperatures of propane oxidation by 30–40 °C. Experimental and DFT investigations reveal that the treatment selectively etches Sr cations and slightly reduces LSCO surface, leading to an increased population of low-valence Co2+ Lewis acid sites, which promotes activation of lattice oxygen and adsorbed oxygen species and facilitates propane adsorption and dissociation. Our work offers a rapid strategy to activate perovskite monolithic catalysts and will inspire the research on surface modification of perovskite catalyst.