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	Unique Catalytic Chemistry of the Nano-confined Systems
	Bao XH(包信和)
	2009-09-13
会议名称	international symposium on relations between homogeneous and heterogeneous catalysis
会议日期	2009-9-13
会议地点	瑞典
页码	33/1
通讯作者	包信和
中文摘要	in the present presentation, the unique characters of the catalysis with the nano-confined systems will be demonstrated, and the emphasis will be laid on the variation of the electron properties derived from the quantum well states in the 2-d nano film and the confinement effects in the interface between the nano-islands of the oxides and noble metallic substrates. the effect of electron quantum confinement on the catalytic activities of 2d ultra-thin metal films is explored by comparing the work function change and the initial reaction rate of atomically flat films of different thickness of lead layers on silicon surfaces, using complementary microscopy and spectroscopy techniques. the obvious oscillations of the oxidation rate of lead films are observed, which are attributed to be a manifestation of the fabry-pe´rot interference modes of electron de broglie waves (quantum well states) in the films. the modulation of the electron density of states near the fermi level opens a new dimension for tuning the catalytic performance of metal systems via size- and thickness-dependent quantum size effects, which will be illustrated through two examples. coordinatively unsaturated iron species, especially those in low valent states, are pivotal for the activation of oxygen-containing reactants. as a result, highly active oxygen species are generated which are essential for the selective oxidation reactions. in the present, we will demonstrate a novel concept to construct a unique high active fe-oxo species on noble metal surfaces through a structural confinement derived by the strange interaction. the fe atoms at the edges of the structures show the nature of the coordinatively unsaturated low-valent state, i.e. feo1-x, at which the adherence of molecular oxygen is remarkably enhanced, and the dissociation of the adsorbed dioxygen presents a barrierless character. the preferential formation of desiccative oxygen species at the boundary of fe-oxo inland modifies essentially the adsorption dynamics between the carbon monoxide and oxygen, which causes a dramatically change of the catalytic performance towards oxidation of carbon monoxide on the surface. an integrated test of the real catalyst with 1 kw pem fuel cell for 1000 hours shows that under the operating condition, with 20% water steam, 30ppm of co in the reforming hydrogen can be completed removed.
会议主办者	瑞典斯德哥尔摩大学
学科主题	物理化学
语种	中文
内容类型	会议论文
源URL	[http://159.226.238.44/handle/321008/113552]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
推荐引用方式 GB/T 7714	Bao XH. Unique Catalytic Chemistry of the Nano-confined Systems[C]. 见:international symposium on relations between homogeneous and heterogeneous catalysis. 瑞典. 2009-9-13.

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