Effect of the loading content of CuO on the activity and structure of CuO/Ce-Mn-O catalysts for CO oxidation
来源期刊:Journal of Rare Earths2015年第6期
论文作者:赵福真 龚渺 李金林
文章页码:604 - 610
摘 要:A urea-nitrate combustion method was used to prepare Ce-Mn-O material, which was applied as the support for a series of CuO /Ce-Mn-O catalysts. The structure of the catalysts was characterized with N2 adsorption/desorption, X-ray diffraction(XRD), temperature-programmed reduction(TPR) and X-ray photoelectron spectroscopy(XPS). The catalytic activity of the catalysts for the oxidation of CO was evaluated on a conventional fixed-bed quartz reactor. XRD results showed that the synergetic effect between manganese and cerium led to a little higher electron density of Ce3+ in the mixed oxides. When the CuO content was lower than 5 wt.%, Cu species were well dispersed onto the Ce-Mn-O support or/and they formed a solid solution with CeO2(inside the fluorite lattice). At higher CuO content(CuO >5 wt.%), large CuO particles were observed. There was strong interaction among ceria, manganese and copper oxide because of the doping of Mn. This interplay changed the reducibility and the valence states of the components, leading to the improved activity of the CuO/Ce-Mn-O catalysts.
赵福真1,龚渺1,李金林1
1. Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Chemistry and Materials,South-Central University for Nationalities
摘 要:A urea-nitrate combustion method was used to prepare Ce-Mn-O material, which was applied as the support for a series of CuO /Ce-Mn-O catalysts. The structure of the catalysts was characterized with N2 adsorption/desorption, X-ray diffraction(XRD), temperature-programmed reduction(TPR) and X-ray photoelectron spectroscopy(XPS). The catalytic activity of the catalysts for the oxidation of CO was evaluated on a conventional fixed-bed quartz reactor. XRD results showed that the synergetic effect between manganese and cerium led to a little higher electron density of Ce3+ in the mixed oxides. When the CuO content was lower than 5 wt.%, Cu species were well dispersed onto the Ce-Mn-O support or/and they formed a solid solution with CeO2(inside the fluorite lattice). At higher CuO content(CuO >5 wt.%), large CuO particles were observed. There was strong interaction among ceria, manganese and copper oxide because of the doping of Mn. This interplay changed the reducibility and the valence states of the components, leading to the improved activity of the CuO/Ce-Mn-O catalysts.
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