Highly enhanced soot oxidation activity over 3DOM Co3O4-CeO2 catalysts by synergistic promoting effect

Guangjun Zhai; Jinguo Wang; Zimei Chen; Shuaifeng Yang; Yong Men

doi:10.1016/j.jhazmat.2018.08.065

Highly enhanced soot oxidation activity over 3DOM Co₃O₄-CeO₂ catalysts by synergistic promoting effect

J Hazard Mater. 2019 Feb 5:363:214-226. doi: 10.1016/j.jhazmat.2018.08.065. Epub 2018 Sep 24.

Authors

Guangjun Zhai¹, Jinguo Wang², Zimei Chen¹, Shuaifeng Yang¹, Yong Men³

Affiliations

¹ College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, PR China.
² College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, PR China. Electronic address: Jinguowang1982@sues.edu.cn.
³ College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, PR China. Electronic address: men@sues.edu.cn.

PMID: 30308360
DOI: 10.1016/j.jhazmat.2018.08.065

Abstract

Three-dimensionally ordered macroporous (3DOM) Co₃O₄-CeO₂ catalysts with controllable Co/Ce molar ratios synthesized by colloidal crystal template method were developed to catalyze the NO_x-assisted soot oxidation for the first time, and the obtained 3DOM Co₃O₄-CeO₂ catalysts exhibited highly enhanced soot oxidation activity. Detailed characterizations of 3DOM Co₃O₄-CeO₂ catalysts revealed that the highly enhanced soot oxidation activity was originated from the synergistic promoting effect by combining the macroporous effect resulted from the unique 3DOM framework, the chemical nature associated with more Co³⁺ reactive sites, the surface enrichment of Ce species and the improved redox properties. Meanwhile, the high NO_x storage and oxidation capacity resulted from the integrated respective merits of Co₃O₄ and CeO₂ also accounted for the enhanced soot oxidation activity via NO_x-assisted mechanism. Furthermore, the 3DOM Co₃O₄-CeO₂ catalysts demonstrated strong stability because of the surface enrichment of Ce species improving the thermal stability and the robust 3DOM framework inhibiting the structural collapse, showing their potential applications under practical conditions.

Keywords: Co(3)O(4)-CeO(2) catalysts; NO(x) storage and oxidation; Soot oxidation; Synergistic promoting effect; Three-dimensionally ordered macroporous.