Preparation, characterization and catalytic performance of ordered macroporous-mesoporous SiO2-supported MnMOx catalysts for soot combustion

In this work, three-dimensionally ordered macroporous-mesoporous SiO2 (3DOM-m SiO2) materials were synthesized by the mesoporous template (P123)-assisted colloidal crystal template (CCT) method and the preparation conditions of 3DOM-m SiO2 were investigated. A series of novel MnMOx/3DOM-m SiO2 (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 SiO2, the suitable conditions, whose reaction temperature is 45 degrees 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 MnMOx/3DOM-m SiO2 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, MnCeOx/3DOM-m SiO2 catalyst give the best catalytic performance and its T-10, T-50, T-90 and S-CO2(m) are 285, 355, 393 degrees C and 98.8 %, respectively.

Automated summary

In this study, three-dimensionally ordered macroporous-mesoporous SiO2 materials and a series of novel MnMOx/3DOM-m SiO2 catalysts were successfully synthesized and characterized. The catalysts showed good catalytic performance for soot combustion, with MnCeOx/3DOM-m SiO2 catalyst exhibiting the best performance.