Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 35: Nanostructures at Surfaces
O 35.1: Poster
Dienstag, 17. März 2015, 18:15–21:00, Poster A
Reactivity of Pt nanocluster arrays — •Karin Gotterbarm, Florian Späth, Udo Bauer, Carina Bronnbauer, Oliver Höfert, Hans-Peter Steinrück, and Christian Papp — Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany
Graphene-supported nanocluster arrays are intriguing systems for the investigation of catalytic processes. We report on the reactivity of Pt nanoparticles deposited on graphene/Rh(111). High resolution XPS was employed to investigate the interaction with CO and SO2 as well as the oxidation of CO. Three CO-induced species are observed in the C 1s core level spectra. These are assigned to CO adsorbed in on-top and bridge terrace sites and step sites in comparison with single crystal data. The step sites are occupied first during adsorption and show the highest desorption temperature, indicating that these are the most stable adsorption sites for CO. The oxidation of CO follows roughly pseudo first order kinetics. The activation energy determined from an Arrhenius analysis was found to be smaller than for stepped platinum crystals. The adsorption and reaction of SO2 is monitored by measuring the S2p core level, showing several SOx (x = 1 - 3) species as intermediates and sulfur as final product on the surface.
This work was supported by SFB 953 "Synthetic Carbon Allotropes".