Oxygen vacancy formation energy in Pd-doped ceria: A DFT+U study
2007 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 127, no 7, 074704- p.Article in journal (Refereed) Published
Using the DFT+U method, i.e., first principles density functional theory calculations with the inclusion of on-site Coulomb interaction, the effects of Pd doping on the O vacancy formation energy (Evac) in CeO2 has been studied. We find that Evac is lowered from 3.0 eV in undoped ceria to 0.6 eV in the Pd-doped compound. Much of this decrease can be attributed to emerging Pd-induced gap states above the valence band and below the empty Ce 4f states. These localized defect states involve the Pd ion and its nearest neighbors, which are also the main acceptors of the extra electrons left on reduction. The effect of the Pd dopant on the geometric structure is very modest for CeO2 but considerable for CeO2−x.
Place, publisher, year, edition, pages
2007. Vol. 127, no 7, 074704- p.
cerium compounds, doping, vacancies (crystal), defect states, electronic structure, density functional theory, palladium
IdentifiersURN: urn:nbn:se:uu:diva-12093DOI: 10.1063/1.2752504ISI: 000248905300025OAI: oai:DiVA.org:uu-12093DiVA: diva2:39862