uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Several different charge transfer and Ce3+ localization scenarios for Rh–CeO2(111)
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
2014 (English)In: Journal of materials chemistry. A, ISSN 2050-7496, Vol. 2, no 7, 2333-2345 p.Article in journal (Refereed) Published
Abstract [en]

We present DFT+U based electronic structure calculations in a p(3 × 3) slab supercell, for low coverages of atomically dispersed Rh interacting with the CeO2(111) surface, comparing Rh as an adatom, and as a dopant substituted into the surface layer. We find that, energetically, a Rh atom approaching a ceria(111) surface with both sparse O and Ce vacancies present strongly prefers to heal the Ce vacancies, but next it prefers to adsorb on a stoichiometric region rather than healing an O vacancy. In the adatom system, Rh is oxidized by electron transfer to a 4f orbital on one Ce ion in the surface layer, which is then nominally converted from Ce4+ → Ce3+ (i.e. Rh adatoms are single donors). We show that there are a number of different local minima, with Ce3+ localization at 1st, 2nd or 3rd nearest neighbour Ce sites. The second neighbour is the most stable, but all are close in energy. In the Rh-doped system (Rh replaces Ce), Rh is oxidized by charge transfer to neighbouring O atoms, and Rh doping leads to deep acceptor and donor states. Rh is not stable in the O sublattice. Moreover, based on vacancy formation energies, we find that oxygen vacancy formation is strongly enhanced in the vicinity of Rh dopants, but slightly suppressed in the vicinity of Rh adatoms.

Place, publisher, year, edition, pages
2014. Vol. 2, no 7, 2333-2345 p.
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-218963DOI: 10.1039/c3ta11169eISI: 000330048400041OAI: oai:DiVA.org:uu-218963DiVA: diva2:698152
Available from: 2014-02-20 Created: 2014-02-20 Last updated: 2014-07-21Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Hermansson, Kersti
By organisation
Structural Chemistry
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 430 hits
ReferencesLink to record
Permanent link

Direct link