Valence State of Active Coper in CuO_x/CeO_2 Catalysists for CO Oxidation

摘要

CuO_x/CeO_2 catalysts were prepared by adsorption-impregnation method. CO conversion was tested over the catalysts pretreated under different conditions for preferential CO oxidation in H_2, and the catalysts were characterized with X-ray photoelectron spectroscopy and temperature programmed reduction . Experimental results show that there are two kinds of copper, which are Cu~+ and Cu~+ in calcined CuO_x7CeO_2. Among them, the Cu~+ is the key active component for CO oxidation. The main reason is as follows: CO is activated by copper for CO oxidation over CCuO_x/CeO_2, while CO can not be activated by Cu2 ~+ . Only when Cu~ + is reduced to Cu~ + or Cu , the copper may be active for CO oxidation, moreover, the experimental results show that the reduction of Cu~+ does not lead to an increase of catalytic activity . So the active species is Cu ~+ in CuO_x/CeO_2 catalysts.