Investigation on the structure-activity relationship of Nb2O5 promoting CeO2-CrOx-Nb2O5 catalysts for 1,2-dichloroethane elimination

Abstract CeO 2 -CrO x -Nb 2 O 5 mixed oxides were synthesized by three different methods (coprecipitation, deposition-precipitation and mechanical mixing) and subjected for 1,2-dichloroethane (DCE) deep oxidation tests. Detailed characterizations such as XRD, UV-Raman, N 2 adsorption/desorption, SEM, XPS, NH 3 -TPD and H 2 -TPR were performed. Results show that the synergistic effect between redox and acid properties are critical for promoting the catalytic oxidation of DCE. The CeCrNb -cp prepared by coprecipitation method presents larger specific surface area and mesopore volume as well as smaller particle sizes. Moreover, the highly dispersed state of (Ce,Cr) x O 2 in the Nb 2 O 5 matrix can enhance the strong interaction between Nb 2 O 5 and (Ce,Cr) x O 2 , facilitate the synergy between surface acid sites and oxidation sites, thus improving the destructive efficiency of DCE. The CeCrNb -cp catalyst exhibits excellent catalytic activity for DCE destruction, high selectivity for less toxic products (HCl and CO 2 ), scarce formation of chlorinated byproduct (C 2 H 3 Cl) and relatively good durability, all of which indicates it would be promising for potential industrial application.