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

Abstract A series of (Ce, Cr) x O 2 /Nb 2 O 5 catalysts with different (Ce, Cr) x O 2 to Nb 2 O 5 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 Nb 2 O 5 significantly improves the intrinsic catalytic activity towards the deep oxidation of DCE, and only a very small amount of C 2 H 3 Cl is detected as the byproduct of the oxidation process. Further study reveals the existence of an obvious synergistic effect between Nb 2 O 5 , with abundant strong acid sites, and (Ce, Cr) x O 2 , with strong oxidation sites, as the strong acid sites of Nb 2 O 5 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.