Elimination of 1,2-dichloroethane over (Ce,Cr)xO2/Nb2O5 catalysts: synergistic performance between oxidizing ability and acidity

A series of (Ce,Cr)(x)O-2/Nb2O5 catalysts with different (Ce,Cr)(x)O-2 to Nb2O5 mass ratios were synthesized by the deposition-precipitation method for use in deep catalytic oxidation of 1,2-dichloroethane (DCE), which is one of the typical chlorinated volatile organic compound pollutants. The textural properties were characterized by X-ray diffraction, N-2 adsorption/desorption isotherms, UV-Raman spectroscopy, and scanning electron microscopy. The surface acidity and the redox properties were characterized by ammonia temperature-programmed desorption and H-2 temperature-programmed reduction, respectively. The results show that the addition of a proper amount of (Ce,Cr)(x)O-2 over Nb2O5 significantly improves the intrinsic catalytic activity towards the deep oxidation of DCE, and only a very small amount of C2H3CI is detected as the byproduct of the oxidation process. Further study reveals the existence of an obvious synergistic effect between Nb2O5, with abundant strong acid sites, and (Ce,Cr)(x)O-2, with strong oxidation sites, as the strong acid sites of Nb2O5 promote the adsorption and dehydrochlorination of DCE, while the strong oxidation sites of (Ce,Cr)(x)O-2 contribute to the deep oxidation of the reactant, intermediates, and byproducts. (C) 2019, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.