密度泛函理论
氧气
离子键合
扩散
空位缺陷
氧化物
离子
结合能
材料科学
化学
计算化学
化学物理
结晶学
原子物理学
热力学
物理
冶金
有机化学
作者
Michael Nolan,Joanne Fearon,Graeme W. Watson
标识
DOI:10.1016/j.ssi.2006.07.045
摘要
Applications of ceria, CeO2 in catalysis and solid oxide fuel cells arise from the relative ease with which oxygen vacancies are formed, producing reactive sites or facilitating ionic diffusion. In this paper, we consider modelling oxygen vacancies in bulk ceria and on the low index surfaces, as well as oxygen vacancy migration in bulk. We apply density functional theory (DFT), corrected for on-site Coulomb interactions, DFT + U, since DFT is unable to describe correctly the electronic structure of defective ceria. We obtain a description of oxygen vacancies consistent with experiment, with localisation of charge on the Ce ions neighbouring the vacancy site. Confirming classical interatomic potential results, the oxygen vacancy formation energy in reduced on surfaces compared to bulk. An elastic band approach is applied to the study of vacancy migration in bulk ceria, yielding a diffusion path and energy barrier which are compared with previous studies.
科研通智能强力驱动
Strongly Powered by AbleSci AI