title: Effects of strong interactions between Ti and ceria on the structures of Ti/CeO2.
abstract: The effects of strong interactions between Ti and ceria on the structures of Ti/CeO2(111) are systematically investigated by density functional theory calculation. To our best knowledge, the adsorption energy of a Ti atom at the hollow site of CeO2is the highest value (-7.99 eV) reported in the literature compared with those of Au (-0.88--1.26 eV), Ag (-1.42 eV), Cu (-2.69 eV), Pd (-1.75 eV), Pt (-2.62 eV) and Sn (-3.68 eV). It is very interesting to find that Ti adatoms disperse at the hollow site of CeO2(111) to form surface TiOxspecies, instead of aggregating to form Ti metal clusters for the Ti-CeO2interactions that are much stronger than those of Ti-Ti ones. Ti adatoms are completely oxidized to Ti4+ions if they are monatomically dispersed on the next near hollow sites of CeO2(111) (xTi-NN-hollow); while Ti3+ions are observed when they locate at the near hollow sites (xTi-N-hollow). Due to the electronic repulsive effects among Ti3+ions, the adsorption energies of xTi-N-hollow are slightly weaker than those of xTi-NN-hollow. Simultaneously, the existence of unstable Ti3+ions on xTi-N-hollow also leads to the restructuring of xTi-N-hollow by surface O atoms of ceria transferring to the top of Ti3+ions, or oxidation by O2adsorption and dissociation. Both processes improve the stability of the xTi/CeO2system by Ti3+oxidation. Correspondingly, surface TiO2-like species form. This work sheds light into the structures of metal/CeO2catalysts with strong interactions between the metal and the ceria support.
authors.affiliation: School of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China. tbt@zjnu.cn.
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Yao
authors.affiliation: School of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China. tbt@zjnu.cn.
authors.forename: Kong-Jie
authors.initials: KJ
authors.lastname: Zhu
authors.affiliation: School of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China. tbt@zjnu.cn.|Department of Chemical & Petroleum Engineering, University of Wyoming, Laramie, WY 82071, USA. mfan@uwyo.edu.
authors.forename: Bo-Tao
authors.initials: BT
authors.lastname: Teng
authors.affiliation: School of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China. tbt@zjnu.cn.
authors.forename: Cao-Ming
authors.initials: CM
authors.lastname: Yu
authors.affiliation: School of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China. tbt@zjnu.cn.
authors.forename: Yun-Lei
authors.initials: YL
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China. tbt@zjnu.cn.
authors.forename: Ya
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemical & Petroleum Engineering, University of Wyoming, Laramie, WY 82071, USA. mfan@uwyo.edu.
authors.forename: Maohong
authors.initials: M
authors.lastname: Fan
authors.affiliation: Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China. wxd@sxicc.ac.cn.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wen