Oxidation of soot promoted by Fe-based spinel catalysts

Abstract

Abstract Diesel engine has attracted much attention because of its good power performance, fuel economy, reliability and durability, but the exhaust gas containing soot has significant impact on environment and human health. Catalyzed diesel particulate filter (CDPF) that reduces the activation energy of soot oxidation by catalysts are used to eliminate soot. In this work, MFe 2 O 4 spinel (M = Cu, Ni and Co) was synthesized by sol-gel method to catalyze the oxidation of soot. The characterization results of MFe 2 O 4 showed that CuFe 2 O 4 possessed the smallest average grain size (65.6 nm) and the best redox performance. The activity tests of the catalysts showed that the activity order of the catalyst is CuFe 2 O 4 (330 °C > CoFe 2 O 4 (411 °C > NiFe 2 O 4 (464 °C. DFT results showed that soot is more easily adsorbed on the O-terminal surface of CuFe 2 O 4 and reacts with oxygen vacancies, resulting in the promotion of soot oxidation by the diffusion of oxygen from the inside to the surface. It also proves that CuFe 2 O 4 has the best catalytic effect on soot.