Physisorbed, Chemisorbed, and Oxidized CO on Highly Active Cu−CeO2(111)

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• 作者：Zongxian Yang ; Bingling He ; Zhansheng Lu ; Kersti Hermansson
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：March 18, 2010
• 年：2010
• 卷：114
• 期：10
• 页码：4486-4494
• 全文大小：301K
• 年卷期：v.114,no.10(March 18, 2010)
• ISSN：1932-7455

文摘

With the use of the DFT+U method, the properties of Cu adsorbed on the stoichiometric CeO₂(111) surface, Cu-doped CeO₂(111) (denoted as Cu_0.08Ce_0.92O₂) surface, and CO oxidation on the stoichiometric Cu_0.08Ce_0.92O₂ surface are studied systematically. It is found that (i) Cu is stable both as an adsorbed atom on the surface and as dopant in the surface region. Cu adsorbed at the surface is Cu(+I) while Cu as a dopant atom is Cu(+II). (ii) The Cu dopant facilitates O-vacancy formation considerably, while Cu adsorption on the stoichiometric CeO₂(111) surface may suppress oxygen vacancy formation. (iii) Physisorbed CO, physisorbed CO₂, as well as chemisorbed CO (carbonate) species are observed on the Cu-doped CeO₂(111) surface, in contrast, on the clean ceria(111) surface, only physisorbed CO was previously observed. C−O distances, adsorption energies, and surface-induced C−O vibrational frequency shifts were used to characterize these species.