Effect of acid/alkali treatment on the structure and catalytic performance of 3DOM CeCo_0.7Mn_0.3O₃ catalyst

In this work, Ce was used as the A-site element and three-dimensional ordered macroporous (3DOM) materials as the template to obtain 3DOM CeCo_0.7Mn_0.3O₃ catalyst via excessive impregnation method. The catalyst was subjected to acid/alkali treatment with dilute nitric acid and sodium hydroxide solutions. The results revealed that the catalysts subjected to acid/alkali treatment exhibited better structural and catalytic activity characteristics than the bulk catalyst. Specifically, the specific surface area of the catalyst treated with acid increased from 34.86 to 60.67 m²·g^-1, and the relative contents of O_ads and Mn⁴⁺ species increased. Moreover, the T_90% further decreased to 174 °C. As for the catalyst treated with alkali, it exhibited a rougher surface and a wider pore size distribution, producing more lattice defects which were favorable for reaction progress. The T_90% was 183 °C, indicating that acid/alkali treatment both had a positive effect on the catalytic oxidation of toluene.