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Catalytic Oxidative Properties and Characterization of CuO/CeO_2 Catalysts 认领 引用 被引量:8
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作者 蒋晓原 周仁贤 +2 位作者 袁骏 吕光烈 郑小明 《Journal of Rare Earths》 SCIE EI CAS 2003年第1期55-59,共5页
The oxidative properties and characterization of CuO, CeO 2 and CuO/CeO 2 cata lysts were examined by means of a CO micro-reactor GC system, TPR, XPS and X-r ay diffraction Rietveld methods. The results show that eith... The oxidative properties and characterization of CuO, CeO 2 and CuO/CeO 2 cata lysts were examined by means of a CO micro-reactor GC system, TPR, XPS and X-r ay diffraction Rietveld methods. The results show that either CuO or CeO 2 ac tivity is quite low for CO oxidation. However, when CuO and CeO 2 are mixed, the oxidative activity of the catalyst increases significantly, probably owing to the valency status of copper species (Cu 2+ and Cu+) on the CeO 2 surfa ce, the dispersion and reducibility. XPS surface analysis shows that CuO loading is very important in forming of either Cu 2+ or Cu+. Rietveld analysis s hows that some CuO, which has smaller ion radius than Ce 4+, enters the Ce O 2 lattice after CuO and CeO 2 are mixed. When the CuO loading reaches 5.0%, the size of CuO crystals is a minimum (6.1 nm) and the micro-strain value i s a maximum (2.86×10 -3), resulting in high surface energy and the best ac tivity for CO oxidation. 展开更多
关键词 physical chemistry CuO/CeO 2 catalysts CO micro-reactor GC system rare earths
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Promotional effect of CO pretreatment on CuO/CeO_2 catalyst for catalytic reduction of NO by CO 认领 引用 被引量:14
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作者 顾贤睿 李昊 +3 位作者 刘礼晨 汤常金 高飞 董林 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第2期139-145,共7页
The CuO/CeO2 catalysts were investigated by means of X-ray diffraction (XRD), laser Raman spectroscopy (LRS), X-ray photoelectronic spectroscopy (XPS), temperature-programmed reduction (TPR), in situ Fourier t... The CuO/CeO2 catalysts were investigated by means of X-ray diffraction (XRD), laser Raman spectroscopy (LRS), X-ray photoelectronic spectroscopy (XPS), temperature-programmed reduction (TPR), in situ Fourier transform infrared spectroscopy (FTIR) and NO+CO reaction. The results revealed that the low temperature (〈150℃) catalytic performances were enhanced for CO pretreated samples. During CO pretreatment, the surface Cu+/Cu0 and oxygen vacancies on ceria surface were present. The low va- lence copper species activated the adsorbed CO and surface oxygen vacancies facilitated the NO dissociation. These effects in turn led to higher activities of CuO/CeO2 for NO reduction. The current study provided helpful understandings of active sites and reaction mechanism in NO+CO reaction. 展开更多
关键词 CuO/CeO2 catalysts CO pretreatment oxygen vacancies NO reduction rare earths
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Preparation, Characterization of CuO/CeO_2 and Cu/CeO_2 Catalysts and Their Applications in Low-Temperature CO Oxidation 认领 引用 被引量:9
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作者 郑修成 韩东战 +4 位作者 王淑萍 张守民 王淑荣 黄唯平 吴世华 《Journal of Rare Earths》 SCIE EI CAS 2005年第1期47-51,共5页
CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were ... CeO2 was synthesized via sol-gel process and used as supporter to prepare CuO/CeO2, Cu/CeO2 catalysts by impregnation method. The catalytic properties and characterization of CeO2, CuO/CeO2 and Cu/CeO2 catalysts were examined by means of a microreactor-GC system, HRTEM, XRD, TPR and XPS techniques. The results show that CuO has not catalytic activity and the activity of CeO2 is quite low for CO oxidation. However, the catalytic activity of CuO/CeO2 and Cu/ CeO2 catalysts increases significantly. Furthermore, the activity of CuO/CeO2 is higher than that of Cu/CeO2 catalysts. 展开更多
关键词 catalytic chemistry CuO/CeO2 catalysts Cu/CeO2 catalysts carbon monoxide oxidation rare earths
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Effect of yttrium addition on water-gas shift reaction over CuO/CeO_2 catalysts 认领 引用 被引量:5
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作者 佘育生 李雷 +3 位作者 詹瑛瑛 林性贻 郑起 魏可镁 《Journal of Rare Earths》 SCIE EI CAS 2009年第3期412-418,共7页
This paper presented a study on the role of yttrium addition to CuO/CeO2 catalyst for water-gas shift reaction. A single-step co-precipitation method was used for preparation of a series of yttrium doped CuO/CeO2 cata... This paper presented a study on the role of yttrium addition to CuO/CeO2 catalyst for water-gas shift reaction. A single-step co-precipitation method was used for preparation of a series of yttrium doped CuO/CeO2 catalysts with yttrium content in the range of 0-5wt.%. Properties of the obtained samples were characterized and analyzed by X-ray diffraction (XRD), Raman spectroscopy, H2-TPR, cyclic voltammetry (CV) and the BET method. The results revealed that catalytic activity was increased with the yttrium content at first, but then decreased with the further increase of yttrium content. Herein, CuO/CeO2 catalyst doped with 2wt.% of yttrium showed the highest catalytic activity (CO conversion reaches 93.4% at 250 ℃) and thermal stability for WGS reaction. The catalytic activity was correlated with the surface area, the area of peak γ of H2-TPR profile (i.e., the reduction of surface copper oxide (crystalline forms) interacted with surface oxygen vacancies on ceria), and the area of peak C2 and A1 (Cu^0→←Cu^2+ in cyclic voltammetry process), respectively. Besides, Raman spectra provided evidences for a synergistic Cu-Ovacancy interaction, and it was indicated that doping yttrium may facilitate the formation of oxygen vacancies on ceria. 展开更多
关键词 CuO/CeO2 catalyst water-gas shift yttrium cyclic voltammetry rare earths
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Preferential oxidation of CO in excess H_2 over the CeO_2/CuO catalyst: Effect of initial support 认领 引用 被引量:2
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作者 Zhiming Gao Yuanyuan Gong +2 位作者 Qiang Zhang Hao Deng Yong Yue 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第4期475-482,共8页
Three series of CeO2/CuO samples were prepared by impregnation method and characterized by XRD, N2 adsorption-desorption, temperatureprogrammed reduction (TPR), XPS and TEM techniques. In comparison with the samples... Three series of CeO2/CuO samples were prepared by impregnation method and characterized by XRD, N2 adsorption-desorption, temperatureprogrammed reduction (TPR), XPS and TEM techniques. In comparison with the samples prepared with CuO as initial support, the samples with Cu(OH)2 as initial support have higher reducibilities and smaller relative TPR peak areas, and also larger specific surface areas at calcina- tion temperatures of 400 ℃--600 ℃. As a result, Cu(OH)2 is better than CuO as initial support for preferential oxidation of CO in excess H2 (CO-PROX). The best catalytic performance was achieved on the sample calcined at 600 ℃ and with an atomic ratio of Ce/Cu at 40%. XPS analyses indicate that more interface linkages Ce-O-Cu could be formed when it was calcined at 600 ℃. And the atomic ratio of Ce/Cu at 40% led to a proper reducibility for the sample as illustrated by the TPR measurements. 展开更多
关键词 preterential oxiclation CO excess H2 CeO2/CuO catalyst TPR XPS interlace
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Effect of Addition of Base on Ceria and Reactivity of CuO/CeO_2 Catalysts for Low-Temperature CO Oxidation 认领 引用 被引量:3
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作者 Xiucheng Zheng Xiaoli Zhang +2 位作者 Shuping Wang Xiangyu Wang Shihua Wu 《Journal of Natural Gas Chemistry》 2007年第2期179-185,共7页
In this work, we have reported the influence of the addition of base (KOH) on the physicochemical property of ceria synthesized by alcohothermal process, and the alcohothermal mechanism was also put forward. Further... In this work, we have reported the influence of the addition of base (KOH) on the physicochemical property of ceria synthesized by alcohothermal process, and the alcohothermal mechanism was also put forward. Furthermore, the prepared CeO2 was used as the support to prepare CuO/CeO2 catalysts via the wet impregnation method. The samples were characterized by N2 adsorption-desorption, X-ray powder diffraction (XRD), high resolution transmission electron microscopy (HRTEM), and temperatureprogrammed reduction by H2 (H2-TPR). The catalytic properties of the CuO/CeO2 catalysts for lowtemperature CO oxidation were studied using a microreactor-GC system. The crystal size of CeO2-A was much smaller than that of CeO2-B, and the corresponding copper oxide catalysts exhibited higher catalytic activity than that of the CeO2-B-supported catalysts under the same reaction conditions. The alcohothermal mechanism indicated that KOH plays a key role in determining the physicochemical and catalytic properties of ceria-based materials. 展开更多
关键词 alcohothermal synthesis ceria CuO/CeO2 catalyst CO oxidation alcohothermal mechanism
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制备方法对CuO/CeO_2-MnO_x催化剂富氢条件下催化氧化CO性能的影响 认领 引用 被引量:6
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作者 龚磊 黄忠 +2 位作者 刘倩 戴润英 魏玲 《中国稀土学报》 CAS CSCD 北大核心 2015年第4期409-417,共9页
分别以一次沉淀法、沉积沉淀浸渍法及直接混合焙烧法制备了Cu O/Ce O2-Mn Ox催化剂,并运用XRD(X射线衍射)、N2吸附脱附、XPS(X射线光电子能谱)、H2-TPR(程序升温还原)等手段对催化剂进行了表征,讨论了Cu O/Ce O2-Mn Ox催化剂的制备方法... 分别以一次沉淀法、沉积沉淀浸渍法及直接混合焙烧法制备了Cu O/Ce O2-Mn Ox催化剂,并运用XRD(X射线衍射)、N2吸附脱附、XPS(X射线光电子能谱)、H2-TPR(程序升温还原)等手段对催化剂进行了表征,讨论了Cu O/Ce O2-Mn Ox催化剂的制备方法对富氢条件下CO催化氧化性能的影响。分析结果表明:沉积沉淀浸渍法制备的Cu O/Ce O2-Mn Ox催化剂并不具有最大的比表面积及最小的晶粒尺寸,但表现出最优的催化活性;沉积沉淀浸渍法使Cu O/Ce O2-Mn Ox催化剂表面分布较多的活性铜物种及丰富的Mn Ox,使得催化剂表面晶格氧含量增多,同时表面羟基、碳酸盐等易导致催化剂失活的物种减少,这些是其具有高催化活性的关键因素。 展开更多
关键词 CuO/CeO2-MnOx催化剂 制备方法 CO氧化 富氢
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