Promoting effect of Nb doping on catalytic performance for deep oxidation of 1, 2-dichloroethane over (Ce,Cr) x O 2 -Nb 2 O 5 catalysts

Abstract

A series of Nb-doped (Ce,Cr)_xO₂-Nb₂O₅ mixed oxides with varying (Ce,Cr)_xO_2/Nb₂O₅ mass ratio were prepared by a co-precipitation method and evaluated for the catalytic performance of eliminating 1,2-dichloroethane (DCE). The results indicate that there exists a strong synergistic effect between acid sites and redox species in (Ce,Cr)_xO₂-Nb₂O₅ improving the catalytic activity for DCE oxidation. Appropriate Nb doping could promote the high dispersion and the interaction of metal oxides in the (Ce,Cr)_xO₂-Nb₂O₅ catalysts, resulting in the formation of more Cr⁶⁺ species with strong oxidizing ability and excellent mobility of oxygen species from bulk to surface to create more active sites for DCE deep oxidation. The (Ce,Cr)_xO₂-Nb₂O₅ catalysts with (Ce,Cr)_xO₂/Nb₂O₅ ratios of 2/1~1/2 exhibit excellent catalytic activity and durability for DCE degradation in dry air as well as benzene or water vapor, and less chlorinated byproduct is produced during the degradation of DCE.