Valence state of active copper in CuO(x)/CeO(2) catalysts for CO oxidation

• Published in: Journal of rare earths Vol. 24; no. 2; pp. 177 - 181
• Main Authors: Zeng, Shanghong, Bai, Xue, Wang, Xiaoyan, Yu, Wenguo, Liu, Yuan
• Format: Journal Article
• Language: English
• Published: 01.04.2006
• ISSN: 1002-0721

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(2+) in calcined CuO(x)/CeO(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 CuO(x)/CeO(2), while CO can not be activated by Cu(2+). Only when Cu(2+) is reduced to Cu(+) or Cu0, the copper may be active for CO oxidation, moreover, the experimental results show that the reduction of Cu(2+) does not lead to an increase of catalytic activity. So the active species is Cu(+) in CuO(x)/CeO(2) catalysts.