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Study of CeO2 and its native defects by density functional theory with repulsive potential


Type

Article

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Authors

Huang, B 
Gillen, R 
Robertson, J 

Abstract

We investigated the native point defects in CeO2 by the density functional (DFT) +U method, and using a non-linear core-corrected norm-conserving Ce pseudopotential. We find the neutral oxygen vacancy (VO 0) in CeO2 to have a very low formation energy of only 0.39eV in the Opoor limit. It is a deep donor with negative U behavior, only stable in its neutral and doubly positive states. The anion Frenkel defect is found to be the lowest energy disorder defect, with a formation energy of only 2.08eV per defect site. These low formation energies arise from the improved transferability of our Ce pseudopotential for its +3 and +4 valence states. The negative U behavior of VO leads to excellent photo-catalytic behavior, while the low formation energy of the anion Frenkel defect leads to a superior oxygen storage-and-release capability.

Description

Keywords

Oxygen vacancy, Frenkel defect, pseudopotential transferability, oxidation catalyst

Journal Title

Journal of Physical Chemistry C

Conference Name

Journal ISSN

1932-7447
1932-7455

Volume Title

118

Publisher

American Chemical Society (ACS)
Sponsorship
Engineering and Physical Sciences Research Council (EP/I014047/1)
All computing facilities and calculation resources receive funding from the Research Grant Council, University Grants Committee of the HKSAR government. BH would like to thank the fund support and calculations resources all supplied by the Department of Physics and Materials Science, City University of Hong Kong.