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O: Fachverband Oberflächenphysik
O 74: Metal Substrates: Adsorption of O and/or H
O 74.3: Vortrag
Donnerstag, 28. Februar 2008, 15:30–15:45, MA 141
Oxidation of palladium surfaces and nanoparticles — •Nicola Seriani1, Florian Mittendorfer1, Georg Kresse1, Jan Klikovits2, Evelyn Napetschnig2, Michael Schmid2, Peter Varga2, Rasmus Westerstrom3, and Edvin Lundgren3 — 1University of Vienna, Austria — 2TU Vienna, Austria — 3Lund University, Sweden
Palladium finds wide application as oxidation catalyst, where a fundamental role is played by the interaction of its surfaces with oxygen. We have investigated formation of adsorption structures and surface oxides on selected Pd surfaces at atomistic level by density functional theory and first-principles thermodynamics as complement to experimental investigations. Surface oxide monolayers with stoichiometry close to that of bulk PdO have been observed and characterized and conditions for their thermodynamic stability have been predicted. Surface free energies of formation are then used in a Wulff construction to predict the shape of nanoscopic particles of palladium in dependence of temperature and oxygen pressure.