Density Functional Theory Study of Sn Adsorption on the CeO2 Surface

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• 作者：Yun Zhao ; Botao Teng ; Zongxian Yang ; Yue Zhao ; Leihong Zhao ; Mengfei Luo
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：August 25, 2011
• 年：2011
• 卷：115
• 期：33
• 页码：16461-16466
• 全文大小：908K
• 年卷期：v.115,no.33(August 25, 2011)
• ISSN：1932-7455

文摘

The adsorption behaviors and electronic properties of Sn on the CeO₂(111) surface were systematically investigated using the density functional theory (DFT) method. Our results suggested that Sn on the hollow site is more stable than that on the top oxygen site at the coverage of 0.25 ML, while Sn on the top oxygen site is the most stable configuration when the coverage of Sn is equal to or higher than 0.5 ML. Charge density difference (CDD) analysis indicates that electrons transfer from the Sn adatom to the substrate, leading to the reduction of Ce⁴⁺ to Ce³⁺ ion, which is in agreement with the experimental spectroscopy. The reduction degree of the substrate increases with the Sn coverage, which is well supported by the CDD and spin-resolved density of states (DOS) of the most stable xSn/CeO₂(111) configurations. The adsorption of Sn can partially activate the surface oxygen of ceria. The tentative study of a probe molecule CO adsorption on the Sn/CeO₂(111) surface indicates that CO adsorption is enhanced due to the strong tin鈥揷eria interactions.