Ag-assisted CeO2 catalyst for soot oxidation

In this work, the Ag loaded Ce-based catalyst was synthesized (by the sol-gel method) and its performance was studied by TG, H2-TPR, XRD, SEM, TEM, BET and XPS. The results show that Ag nanoparticles be successfully loaded onto the CeO2 surface and the relative content of Ag nanoparticles is about 10.22 wt.% close to the theoretical value (10%). XPS shows that Ag nanoparticles induce a great number of oxygen vacancies in the CeO2 lattice through the electronic transfer, and H2-TPR indicates that the Ag-assisted CeO2 catalyst exhibits a better reduction performance and Ag nanoparticles can promote O- transform into O2-. The catalytic activity for soot oxidation was studied by TG under air atmosphere and the activity was found to be obviously enhanced when Ag nanoparticles be load on the surface of CeO2 (T10 = 386 °C, T90 = 472.5 °C, Tm = 431 °C). The reaction mechanism was also presented and O2- species is regarded as the determinant factor for the catalytic activity.