Synergetic effects of CuO and CeO₂ on hydrogen chloride catalytic oxidation

CuO/Y, CeO₂/Y and CuO-CeO₂/Y catalysts for hydrogen chloride oxidation were prepared by impregnation method. The catalysts were characterized by means of scanning electron microscope (SEM), X-ray diffraction(XRD), Brurauer Emmerr Teller Procedure(BET), Raman and temperature programmed reduction(H₂-TPR). The results of SEM, XRD and BET showed that the structure of the catalysts kept stable during the reaction. CuO and CeO₂ displayed different reaction character: CuO was chlorinated, and the aggregation of the chlorinated copper species resulted in the decreasing of surface area of CuO/Y-U; while CeO₂ did not undergo chlorinated and become more disperse. The results of the catalytic performance test showed that CuO-CeO₂/Y catalyst exhibited the highest activity, and the conversion of HCl was 90% at 390°C, indicating the significant synergetic effects between CuO and CeO₂. The results of Raman and H₂-TPR showed that cupric ion entered into CeO₂ lattice, leading to the lattice deformation. On the other hand, CeO₂ could improve the dispersion and redox property of CuO. Over the CuO-CeO₂/Y catalyst, the high dispersion of copper species was responsible for the high catalytic performance.