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 e_g 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.