Quenching-induced surface modulation of perovskite oxides to boost catalytic oxidation activity

Quenching is a powerful method for modulating surface structures of metal oxide nanocatalysts to achieve high catalytic oxidation activities, but it is still challenging. Herein, a catalyst of ultrafine Co₃O₄ nanoparticles decorated on Co-doped LaMnO₃ (Co₃O₄/LaCo_xMn_1-xO₃) is synthesized via one-step quenching perovskite-type LaMnO₃ nanocatalyst into an aqueous solution of cobalt nitrate, which exhibits significantly improved catalytic performance with toluene (1000 ppm) conversion of 90% at 269 °C under the gas hourly space velocity of 72000 mL g^-1 h^-1. The high catalytic activity correlates with large surface area, abundant oxygen vacancies and good reducibility. Furthermore, density functional theory calculations disclose that Co doping and interfacial effect of Co₃O₄/LaCo_xMn_1-xO₃ can achieve lower C-H bond activation energy. These findings provide a unique and effective route towards surface modification of nanocatalysts.