Oxygen vacancy pairs were suggested to play a role in the reduction of NO
molecules on ceria and for the oxidation processes of reducible rare-earth oxides.
The formation energy of the oxygen vacancy pairs and the changes in the structural
and electronic properties of the ceria (110) surface with oxygen vacancy pairs were
investigated using density-functional theory (DFT+U) methodology within the
generalized gradient approximation. It was found that the excess electrons localize
on the Ce ions neighbouring the vacancies, and the most stable structure for the
oxygen vacancy pairs on the ceria (110) surface was at next-nearest-neighbour site.
Oxygen Vacancy Pairs on CeO2(110): a DFT+U Study. Z.Yang, X.Yu, Z.Lu, S.Li,
K.Hermansson: Physics Letters A, 2009, 373[31], 2786-92