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O: Fachverband Oberflächenphysik
O 49: Surface Chemical Reactions and Heterogeneous Catalysis III
O 49.3: Vortrag
Mittwoch, 2. April 2014, 11:00–11:15, PHY C 213
Interaction and reactivity between H2O and CO on Au(310) — •Matthijs van Spronsen1, Angela den Dunnen2, Maarten van Reijzen2, Christine Hahn2, Kees-Jan Weststrate3, and Ludo Juurlink2 — 1Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA, Leiden, The Netherlands — 2Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA, Leiden, the Netherlands — 3Technische Universiteit Eindhoven, Postbus 513, 5600 MB, Eindhoven, the Netherlands
Important discoveries show significant activity of supported Au nanoparticles in the oxidation of CO [1]. Furthermore, it also has been showed recently that water promotes the reactivity [2]. Both the remarkable activity of the Au nanoparticles and the promoting effect of water have not been completely understood. To study the effect of low coordinated Au atoms, the interaction between H2O and CO has been studied on the stepped Au(310) by Temperature Desorption Spectroscopy and high resolution X-ray Photoelectron Spectroscopy under Ultra High Vacuum conditions. In contrary to the Au(111) surface, desorption of H2O occurs in two peaks indicating stronger interaction of H2O with the low coordinate sites in the Au(310) surface. However, no fragmentation or reaction with CO has been detected. Electron irradiation of the adsorbed H2O layers creates a mixture of H2O, OH and O. In this mixture both OH and O show high reactivity to CO oxidation even at temperatures as low as 123 K.
[1] M. Haruta, et al, Chemistry Letters, no. 2, pp. 405-408, 1987. [2] M. Daté,et al, Angewandte , vol. 43, pp. 2129-2132, Apr. 2004.