Valence State of Active Copper in CuOx/CeO2 Catalysts for CO Oxidation
来源期刊：JOURNAL OF RARE EARTHS2006年第2期
论文作者：Zeng Shanghong Liu Yuan Wang Xiaoyan Yu Wenguo Bai Xue
Key words：active center; carbon monoxide; ceria; copper; preferential oxidation; hydrogen production; rare earths;
Abstract: CuOx/CeO2 catalysts were prepared by adsorption-impregnation method.CO conversion was tested over the catalysts pretreated under different conditions for preferential CO oxidation in H2, 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 Cu2+ in calcined CuOx/CeO2.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 CuOx/CeO2, while CO can not be activated by Cu2+.Only when Cu2+ is reduced to Cu+ or Cu0, the copper may be active for CO oxidation, moreover, the experimental results show that the reduction of Cu2+ does not lead to an increase of catalytic activity.So the active species is Cu+ in CuOx/CeO2 catalysts.
Zeng Shanghong1，Liu Yuan1，Wang Xiaoyan2，Yu Wenguo2，Bai Xue2
(1.Department of Catalysis Sciences and Technology, College of Chemical Engineering, Tianjin University, Tianjin 300072, China;
2.School of Chemical Engineering, Inner Mongolia University of Technology, Huhhot 010062, China)
Abstract:CuOx/CeO2 catalysts were prepared by adsorption-impregnation method.CO conversion was tested over the catalysts pretreated under different conditions for preferential CO oxidation in H2, 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 Cu2+ in calcined CuOx/CeO2.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 CuOx/CeO2, while CO can not be activated by Cu2+.Only when Cu2+ is reduced to Cu+ or Cu0, the copper may be active for CO oxidation, moreover, the experimental results show that the reduction of Cu2+ does not lead to an increase of catalytic activity.So the active species is Cu+ in CuOx/CeO2 catalysts.
Key words:active center; carbon monoxide; ceria; copper; preferential oxidation; hydrogen production; rare earths;
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