Water鈥揋as Shift Reaction on Metal Nanoclusters Encapsulated in Mesoporous Ceria Studied with Ambient-Pressure X-ray Photoelectron Spectroscopy

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• 作者：Cun Wen ; Yuan Zhu ; Yingchun Ye ; Shiran Zhang ; Fang Cheng ; Yi Liu ; Paul Wang ; Franklin (Feng) Tao
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：October 23, 2012
• 年：2012
• 卷：6
• 期：10
• 页码：9305-9313
• 全文大小：627K
• 年卷期：v.6,no.10(October 23, 2012)
• ISSN：1936-086X

文摘

Metal nanoclusters (Au, Pt, Pd, Cu) encapsulated in channels of mesoporous ceria (mp-CeO₂) were synthesized. The activation energies of water鈥揼as shift (WGS) reaction performed at oxide鈥搈etal interfaces of metal nanoclusters encapsulated in mp-CeO₂ (M@mp-CeO₂) are lower than those of metal nanoclusters impregnated on ceria nanorods (M/rod-CeO₂). In situ studies using ambient-pressure XPS (AP-XPS) suggested that the surface chemistry of the internal concave surface of CeO₂ pores of M@mp-CeO₂ is different from that of external surfaces of CeO₂ of M/rod-CeO₂ under reaction conditions. AP-XPS identified the metallic state of the metal nanoclusters of these WGS catalysts (M@mp-CeO₂ and M/rod-CeO₂) under a WGS reaction condition. The lower activation energy of M@mp-CeO₂ in contrast to M/rod-CeO₂ is related to the different surface chemistry of the two types of CeO₂ under the same reaction condition.

Keywords:

catalysis; water%E2%88%92gas+shift&qsSearchArea=searchText">water鈭抔as shift; ambient-pressure X-ray photoelectron spectroscopy; ceria; in situ