Тип публикации: статья из журнала
Год издания: 2010
Идентификатор DOI: 10.1002/pssb.200945452
Аннотация: We calculated the structures of and analyzed the bonding in adsorption complexes of small gold species Au-n on alpha-Al2O3(0001), n = 1-6, and gamma-Al2O3(0001), n = 1-5. We applied a scalar-relativistic gradient-corrected density functional (DF) method to cluster models of the support that were embedded in an extended elastic polaПоказать полностьюrizable environment (EPE). The shortest AuO distances, 204-211 pm, are consistent with extended X-ray adsorption fine structure (EXAFS) data for gold clusters on alumina surfaces. The calculated total adsorption energies increase with cluster nuclearity, up to n = 4, but drop for larger adsorbed species. In the gas phase, these small gold clusters exhibit a planar structure which they keep, oriented parallel to the surface, as adsorbates on alpha-Al2O3(0001). Unfavorable energy contributions result for larger clusters as their planar shape is notably distorted by the interaction with the support which amounts to 0.5-1.5 eV. On gamma-Al2O3(0001), also the larger gold clusters retain their intrinsic planar structure as they adsorb oriented perpendicular to the surface. The corresponding adsorption energies are slightly smaller, 0.3-1.2 eV. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Журнал: PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
Выпуск журнала: Vol. 247, Is. 5
Номера страниц: 1023-1031
ISSN журнала: 03701972
Место издания: WEINHEIM
Издатель: WILEY-V C H VERLAG GMBH