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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 42.91: Poster
Mittwoch, 25. März 2009, 17:45–20:30, P2
Reaction of Methanol on functionalized Ruthenium — •Pawel Gazdzicki and Peter Jakob — Fachbereich Physik, Philipps-Universität Marburg, D-35032 Marburg, Germany
Infrared Absorption Spectroscopy and Temperature-Programmed Desorption were used to study the adsorption and reaction of methanol on various functionalized Ru(0001) surfaces. The used substrates were the clean Ru(0001) surface, Ru(0001) precovered with 0.5 and 1 ML D, Ru(0001)-(2× 2)-O, Ru(0001)-(2× 1)-O and a pseudomorphic Cu monolayer on the Ru(0001) surface.
From the vibrational modes of the isotopes CH3OH and CH3OD clear evidence for intact adsorption at T=80 K has been found for all investigated substrates. This finding contradicts previous studies which suggested an OH (OD) bond scission upon adsorption of methanol on Ru(0001) and Ru(0001)-(2× 2)-O, even at low temperatures, as well as recombinative desorption at elevated T.
The thermal evolution varies considerably for the individual surfaces with the prominent methoxy (CH3O) species being produced on clean Ru(0001) and Cu/Ru(0001) only. On the oxygen (pre)covered surfaces methanol predominantly desorbs without reaction; a small fraction decomposes directly to form CO and H without forming any detectable intermediates. Finally, 1 ML D/Ru(0001) largely passivates the surface and methanol adsorption is fully reversible.