Ce–Mn Synergy in Zr-Stabilized Three-Dimensionally Ordered Macromesoporous Oxides for Superior Soot Combustion

A series of three-dimensionally ordered macromesoporous (3DOMM) Ce x Mn 0.3-x Zr 0.7 O δ catalysts were synthesized by an evaporation-induced self-assembly combined with a colloidal crystal template (EISA-CCT) method. These catalysts exhibit excellent soot combustion activity and possess an intact 3DOMM structure. The electronic synergy between Mn and Ce was investigated. Mn facilitates the reduction of Ce 4+ to Ce 3+ and the generation of oxygen vacancies, thereby increasing active oxygen species, while Ce oxidizes Mn 2+ to Mn 3+ /Mn 4+, which enhances the intrinsic redox ability and NO oxidation. Among the tested samples, the Ce 0.15 Mn 0.15 Zr 0.7 O δ catalyst exhibits activity comparable to that of noble-metal catalysts and excellent stability, which can be attributed to the maximized Ce–Mn synergy and the intact 3DOMM morphology.