Regensburg 2016 – scientific programme
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O: Fachverband Oberflächenphysik
O 64: Oxides and Interfaces: Adsorption II
O 64.9: Talk
Wednesday, March 9, 2016, 17:00–17:15, H6
CO adsorption on small Aun (n = 1–4) structures supported on magnetite (111) surface — •Tomasz Pabisiak1, Maciej J. Winiarski1,2, and Adam Kiejna1 — 1Institute of Experimental Physics, University of Wrocław, Wrocław, Poland — 2Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław, Poland
The adsorption of CO on Aun nanostructures (n = 1–4) formed on the Fe-terminated (111) surface of magnetite (Fe3O4) was studied using density functional theory in the generalized gradient approximation of Perdew-Burke-Ernzerhof form with Hubbard correction U, accounting for
strong electron correlations.
The structural, energetic, and electronic properties were examined for two classes of configurations of the adsorbed Aun structures. The flattened ones of bilayer-like structure, were found energetically more favored than
vertical ones. For both classes of structures the adsorption binding energy increases with the number of Au atoms in a gold structure. A detailed analysis of the bonding charge and of the electron charge rearrangements at the Aun/oxide contacts is presented.
It is found that the CO adsorption binding to the Fe3O4(111) supported Aun is up to twice as strong as to the bare magnetite surface. Analysis of charges on the atoms showed that in each case CO binds to the most positively charged (cationic) atom of the Aun structure. Changes in the electronic structure of the Aun species and of the oxide support are discussed.
This work was supported by the National Science Center (NCN), Poland, Grant No.2012/07/B/ST3/03009.