xO 2-Nb 2O 5 catalysts]]>

摘要

A series of Nb-doped (Ce,Cr)~(x)O~(2)-Nb~(2)O~(5)mixed oxides with varying (Ce,Cr)~(x)O~(2/)Nb~(2)O~(5)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)~(x)O~(2)-Nb~(2)O~(5)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)~(x)O~(2)-Nb~(2)O~(5)catalysts, resulting in the formation of more Cr_(6+)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)~(x)O~(2)-Nb~(2)O~(5)catalysts with (Ce,Cr)~(x)O~(2)/Nb~(2)O~(5)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.