Facilitated vacancy formation at Zr-doped ceria(1 1 1) surfaces
2008 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 602, no 6, 1199-1206 p.Article in journal (Refereed) Published
The effects of Zr doping on the atomic and electronic properties of the ceria(1 1 1) surface are studied using first-principles density functional theory with the inclusion of on-site Coulomb interaction. The atomic structures, electronic structure, and the vacancy formation energies of the Zr-doped and undoped ceria(1 1 1) surfaces are compared. It is found that (i) Zr doping induces a severe distortion of the unreduced surface structure; (ii) at the reduced Zr-doped ceria(1 1 1) surface, the oxygen anions around the oxygen vacancy show much larger displacements than those on the pure CeO2(1 1 1) surface; (iii) an oxygen vacancy is more easily formed around the Zr dopant, and the reduction energy is lowered by about 0.5 eV; (iv) the excess electrons left by the removed oxygen atom localize on the two Ce cations neighboring the vacancy and thus brings about the reduction of the two Ce4+ ions; and (v) the atomic structure modification induced by the Zr doping plays a vital role in facilitating the reduction of the ceria–zirconia solid solution as compared to the pure ceria.
Place, publisher, year, edition, pages
2008. Vol. 602, no 6, 1199-1206 p.
Density functional calculations; DFT + U; Atomic structure; Electronic structure; Zr-doped ceria;
Research subject Inorganic Chemistry
IdentifiersURN: urn:nbn:se:uu:diva-108303DOI: 10.1016/j.susc.2008.01.013ISI: 000255098700010OAI: oai:DiVA.org:uu-108303DiVA: diva2:235244