Accelerating effect of ZrO2 doping on catalytic performance and thermal stability of CeO2-CrOx mixed oxide for 1,2-dichloroethane elimination

摘要

A series of CeO2-ZrO2-CrOx mixed oxides with different Ce/Zr molar ratios were synthesized by co-precipitation method and tested for deep catalytic oxidation of 1,2-dichloroethane (DCE), as one of the typical chlorinated VOCs pollutants. The results show that the addition of proper amount of ZrO2 significantly improves the catalytic activity of CeO2-CrOx, and only very slight C2H3Cl is detected as the sole byproduct in the oxidation process, due to the relative concentration of oxygen vacancies and Cr6+ species on the catalysts being increased. Moreover, though aged at 700 degrees C for 4 h, the catalytic performances and the thermal stability of the aged CeO2-ZrO2-CrO5 catalysts can be maintained to a large extent, especially for the CZCr catalyst (atom molar ratio Ce:Zr:Cr = 2:2:1). It may be related to that smaller Zr and Cr ions are embedded into CeO2 lattice to form solid solution and thus the structure stability being maintained. Besides, the catalysts exhibit good durability for 1,2-dichloroethane oxidation during the long-term continuous test, whether in dry air or in the existence of water and non-chlorinated VOCs, indicating that the CeO2-ZrO2-CrOx catalysts deserve more attention and may be potential for industrial application. (C)2015 Elsevier B.V. All rights reserved.