A study on the catalytic synergy effect between noble metals and cobalt phases in Ce-Al-O supported catalysts

	A study on the catalytic synergy effect between noble metals and cobalt phases in Ce-Al-O supported catalysts
	Meng, M; Zha, YQ; Luo, JY; Hu, TD; Xie, YN; Liu, T; Zhang, J; Hu TD(胡天斗); Xie YN(谢亚宁); Liu T(刘涛)
刊名	APPLIED CATALYSIS A-GENERAL
	2006
卷号	301 期号:2 页码:#REF!
关键词	Co-Pt(Pd CO oxidation hydrogen spillover oxygen spillover catalytic synergy effect structural characterization Rh)/Ce-Al-O catalysts
通讯作者	Meng, M (reprint author), Tianjin Univ, Sch Chem Engn & Technol, Dept Catalysis Sci & Technol, Tianjin 300072, Peoples R China.
英文摘要	A series of Co-Pt(Pd, Rh)/Ce-Al-O catalysts were prepared by successive wetness impregnation method. The catalytic activities of the samples for CO oxidation were evaluated in a flow fixed-bed micro-reactor. The techniques of XRD, XPS, EXAFS, H-2-TPR and TPO-MS were employed to characterize the catalysts. The results of activity measurement show that for CO oxidation the presence of a small amount of noble metals greatly enhances the activity of Co/Ce-Al-O catalyst, the existence of cerium has increased the activity of the samples because of its capacity for oxygen storage and the interaction between cerium oxide and cobalt phase. The structural characterization results of XRD, XPS and EXAFS indicate that the cobalt in Co-Pt(Pd, Rh)/Ce-Al-O catalysts exists as metallic phase, while in Co/Ce-Al-O catalyst only part of the cobalt has been reduced to zero valence, the rest exists as Co-Al spinel which cannot be reduced at 450 degrees C by H-2. H-2-TPR results suggest that the hydrogen spillover may occur during the reduction pretreatment, and therefore increasing the reduction deepness of cobalt phases. The results of TPO-MS show that the oxygen spillover from noble metals to cobalt phase during CO oxidation is very potential. It decreases the activation energy of CO oxidation reaction and results in a prominent increase of the activity. The spilled over species, such as atomic H and O, generated on noble metal sites are mobile on the surface of the catalysts, which makes both of the close and remote cobalt phases involve in reactions at lower temperatures. Additionally, the coordination numbers from EXAFS indicate that the presence of noble metals greatly enhances the dispersion of cobalt phases. The order of this enhancement effect is Pt > Pd > Rh. As a result, the oxygen spillover effect and the enhancement effects on the reduction deepness and the dispersion of cobalt phases should be the main contributions to the catalytic synergy effect between cobalt phases and noble metals. (c) 2005 Elsevier B.V. All rights reserved.
学科主题	Chemistry; Environmental Sciences & Ecology
类目[WOS]	Chemistry, Physical ; Environmental Sciences
收录类别	SCI
WOS记录号	WOS:000235583100001
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/226491]
专题	高能物理研究所_多学科研究中心
推荐引用方式 GB/T 7714	Meng, M,Zha, YQ,Luo, JY,et al. A study on the catalytic synergy effect between noble metals and cobalt phases in Ce-Al-O supported catalysts[J]. APPLIED CATALYSIS A-GENERAL,2006,301(2):#REF!.
APA	Meng, M.,Zha, YQ.,Luo, JY.,Hu, TD.,Xie, YN.,...&张静.(2006).A study on the catalytic synergy effect between noble metals and cobalt phases in Ce-Al-O supported catalysts.APPLIED CATALYSIS A-GENERAL,301(2),#REF!.
MLA	Meng, M,et al."A study on the catalytic synergy effect between noble metals and cobalt phases in Ce-Al-O supported catalysts".APPLIED CATALYSIS A-GENERAL 301.2(2006):#REF!.