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O: Fachverband Oberflächenphysik
O 30: Inorganic/Organic Interfaces: Towards Application
O 30.7: Vortrag
Dienstag, 17. März 2015, 15:30–15:45, MA 043
Adsorption of organic molecules on a water-covered Fe(100) surface from first-principles — •Gregor Feldbauer1,2, Pedro Bedolla2, Michael Wolloch2, Peter Mohn1, Josef Redinger1, and András Vernes1,2 — 1Institute of Applied Physics, Vienna University of Technology, Vienna, Austria — 2Austrian Center of Competence for Tribology, Wiener Neustadt, Austria
Biofuels, especially ethanol mixed with standard gasoline or diesel, have become an important part of the worldwide motor fuel consumption. [1] Hence, the interaction of organic molecules constituting such biofuels with metallic surfaces is of high technological interest. In a combustion engine apart from organic molecules of the pure fuel there are always other chemical constituents, which may change the interfacial properties of the metallic surface. Water or acids contained in fuel lubricity additives and trace contaminants are prominent examples. In this contribution, the adsorption of ethanol, isooctane and acetic acid on a bare and a water-covered bcc Fe(100) surface is investigated within the framework of density functional theory including van der Waals interactions. In particular, the impact of a water mono-layer on the adsorption energies, equilibrium configurations and electronic charge distributions is discussed. It is shown that the effect of the water layer strongly depends on the type of bond between the molecule and the surface. In addition, the possibility of a dissociative adsorption of the acetic acid and the formation of molecular hydrogen is studied.
[1] IEA, Tracking Clean Energy Progress 2013; International Energy Agency, Paris, 2013