Perovskite evolution on La modified Mn_1.5Co_1.5O₄ spinel through thermal ageing with enhanced oxidation activity: Is sintering always an issue?

Non-precious metal oxides have great potential in catalytic deep oxidation of emitted hydrocarbons to help address various environmental pollution concerns. However, sintering issue is a stumbling block in practical application upon long-term high-temperature operation or thermal shock experience. Herein, La was applied to modify Mn1.5Co1.5O4 spinel to get a highly active oxidation catalyst with exceptional stability against hightemperature thermal ageing treatment. With thermal ageing at 750 degrees C for 100 h, the La modified Mn-Co composite reached 90 % conversion in toluene oxidation at 265 degrees C under the high WHSV of 120,000 mL g-1 h-1, while this value increased to 312 degrees C over blank Mn-Co spinel. The addition of La not only inhibited the growth of spinel nanocrystals, but also brought about perovskite formation through sintering, generating perovskite-spinel interfaces, thus enhancing both activity and stability. Meanwhile, the La modified Mn-Co spinel exhibited superior performance in presence of water or sulfur dioxide after thermal ageing treatment. This work offers a versatile strategy to design anti-sintering and active oxidation nanocatalysts based on non-precious metal oxides for industrial applications.