Dresden 2009 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 42: Poster Session II (Nanostructures at surfaces: arrays; Nanostructures at surfaces: Dots, particles, clusters; Nanostructures at surfaces: Other; Nanostructures at surfaces: Wires, tubes; Metal substrates: Adsorption of O and/or H; Metal substrates: Clean surfaces; Metal substrates: Adsorption of organic/bio moledules; Metal substrates: Solid-liquid interfaces; Metal substrates: Adsorption of inorganic molecules; Metal substrates: Epitaxy and growth; Heterogeneous catalysis; Surface chemical reactions; Ab-initio approaches to excitations in condensed matter; Organic, polymeric, biomolecular films– also with adsorbates; Particles and clusters)

O 42.89: Poster

Mittwoch, 25. März 2009, 17:45–20:30, P2

Pressure gap in electrochemically induced oxygen spillover at Pt/YSZ electrodes — •Arafat Toghan, Liz Rösken, and Ronald Imbihl — Institut für Physikalische Chemie und Elektrochemie, Leibniz-Universität Hannover, Callinstr.3-3a, D-30167 Hannover, Germany

Upon application of a pumping voltage to Pt electrodes on the oxygen-ion conducting solid electrolyte YSZ (yttria-stabilized zirconia) we observe the spillover of discharged oxygen atom onto the Pt surface. The spillover which represents the basis of the electrochemical promotion of heterogeneously catalyzed reactions has been investigated in the past at low pressure, at p < 10-4 mbar. We extend here these studies up to 1 mbar using in situ XPS at BESSY. We use (111) oriented YSZ single crystals, oriented Pt (111) electrodes were prepared by sputtering of Pt target on the surface of a single crystal YSZ (111) using magnetron sputtering technique in inert argon atmosphere at room temperature. The electrodes were characterized by scanning electron microscope(SEM) and by photoelectron emission microscopy(PEEM).