Regulating the Redox Cycle of Highly Dispersed CuMn2O4 on SiO2 for Toluene Catalytic Combustion

Controlling the crystal structure and composition of spinel and regulating the redox cycle can effectively improve the catalytic activity of spinel. In this paper, highly dispersed CuMn2O4 was synthesized by utilizing the high specific surface area of a porous SiO2 carrier and its hydroxyl anchoring effect, and the Cu–Mn ion ratio was adjusted to optimize the Cu–Mn redox cycle. The hydroxyl group anchoring function effectively complexed the Cu–Mn metal ions, ensuring the generation of the CuMn2O4 phase. This not only enhanced the dispersion of CuMn2O4 but also reduced the appearance of monometallic oxides. The higher proportions of Cu+ and Mn4+ in the catalysts promoted the appearance of abundant oxygen vacancies and effectively polished oxygen adsorption and activation. High Mn eg occupancy also changed the oxidation activity of spinel by affecting the adsorption of intermediates. This work provides a general strategy for the synthesis of high-activity and stable catalysts.