Three-dimensional ordered macroporous-mesoporous SiO 2 was successfully synthesized by combination of hard and soft templates method. 3DOM-m SiO 2 supported MnMO x catalysts (M: Fe, Co, Ni, Cu, Zn, La, Ce) were prepared and they exhibit good catalytic performance for soot combustion. Among them, MnCeOx/3DOM-m SiO 2 exhibits the highest catalytic activity. [Display omitted] • 3DOM-m SiO 2 was successfully synthesized by combining hard and soft templates. • MnMO x /3DOM-m SiO 2 catalysts have three-dimensionally ordered macropore and mesopore. • MnMO x /3DOM-m SiO 2 catalysts show high catalytic activity for soot combustion. In this work, three-dimensionally ordered macroporous-mesoporous SiO 2 (3DOM-m SiO 2) materials were synthesized by the mesoporous template (P123)-assisted colloidal crystal template (CCT) method and the preparation conditions of 3DOM-m SiO 2 were investigated. A series of novel MnMO x /3DOM-m SiO 2 (M: Fe, Co, Ni, Cu, Zn, La, Ce) catalysts were successfully prepared by a facile incipient-wetness impregnation method. The as-prepared catalysts were characterized by means of N 2 -adsorption-desorption isotherms, XRD, SEM, TEM, H 2 -TPR and O 2 -TPD and so on. For the synthesis of 3DOM-m SiO 2 , the suitable conditions, whose reaction temperature is 45 °C, the ratio of P123 to TEOS is 0.533 and ratio of water to ethanol is 0.5, were obtained by modifying reaction conditions. The as-prepared MnMO x /3DOM-m SiO 2 catalysts also maintain well-defined macroporous and mesoporous structures after the loading process. Meanwhile, they exhibit good catalytic performance for soot combustion. Among the studied catalysts, MnCeO x /3DOM-m SiO 2 catalyst give the best catalytic performance and its T 10 , T 50 , T 90 and Sm CO2 are 285, 355, 393 °C and 98.8 %, respectively. [ABSTRACT FROM AUTHOR]