Investigation on the structure-activity relationship of Nb2O5 promoting CeO2-CrO2-Nb2O5 catalysts for 1,2-dichloroethane elimination

CeO2-CrOx-Nb2O5 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, NH3-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 Nb2O5 matrix can enhance the strong interaction between Nb2O5 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 (HCI and CO2), scarce formation of chlorinated byproduct (C2H3Cl) and relatively good durability, all of which indicates it would be promising for potential industrial application.