文献类型：期刊文献

英文题名：Clustering of Oxygen Vacancies at CeO2(111): Critical Role of Hydroxyls

作者：Wu, Xin-Ping;Gong, Xue-Qing[1]

机构：[1]E China Univ Sci & Technol, Ctr Computat Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China; E China Univ Sci & Technol, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2016

卷号：116

期号：8

外文期刊名：PHYSICAL REVIEW LETTERS

收录：;EI(收录号：20161002057161);WOS:【SCI-EXPANDED(收录号:WOS:000370847100006)】；

基金：We are grateful for financial support from the National Natural Science Foundation of China (Grants No. 21421004, No. 21322307), "Shu Guang" project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation (Grant No. 13SG30) and the Fundamental Research Funds for the Central Universities (Grant No. WD1313009). The authors also thank the computing time in the National Super Computing Center in Jinan.

语种：英文

外文关键词：Scanning tunneling microscopy - Cerium oxide - Density functional theory - Surface defects

摘要：By performing density functional theory calculations corrected by an on site Coulomb interaction, we find that the defects at the CeO2(111) surface observed by the scanning tunneling microscopy (STM) measurements of Esch et al. [Science 309, 752 (2005)] are not mere oxygen vacancies or fluorine impurities as suggested by Kullgren et al. [Phys. Rev. Lett. 112, 156102 (2014)], but actually the hydroxyl-vacancy combined species. Specifically, we show that hydroxyls play a critical role in the formation and propagation of oxygen vacancy clusters (VCs). In the presence of neighboring hydroxyls, the thermodynamically unstable VCs can be significantly stabilized, and the behaviors of oxygen vacancies become largely consistent with the STM observations. In addition to the clarification of the long term controversy on the surface defect structures of CeO2(111), the "hydroxyl-vacancy model" proposed in this work emphasizes the coexistence of hydroxyls and oxygen vacancies, especially VCs, which is important for understanding the catalytic and other physicochemical properties of reducible metal oxides.