Berlin 2005 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 3: Oberfl
ächenreaktionen I
O 3.1: Vortrag
Freitag, 4. März 2005, 10:45–11:00, TU EB420
Investigation of Au/TiO2 model catalysts prepared from micellar stabilized gold particles — •S. Kielbassa1, F. Weigl2, A. Ethirajan2, H.G. Boyen2, P. Ziemann2 und R.J. Behm1 — 1Abt. Oberflächenchemie und Katalyse, Universität Ulm, 89069 Ulm — 2Abt. Festkörperphysik, Universität Ulm, 89069 Ulm
Metal oxide supported Au catalysts have attracted considerable interest over the last years because of their high activity for low-temperature oxidation and hydrogenation reactions. For studying particle size and transport effects, we prepared model systems with a narrow distribution for particle sizes and particle separations by depositing Au loaded diblock copolymer micelles onto atomically smooth TiO2 (110) rutile substrates. Removing of the polymer shells in an oxygen plasma leads to a hexagonal arrangement of Au particles. The stability of these model systems in typical activation and reaction atmospheres/temperatures as well as their activity for CO oxidation under high pressure conditions was investigated for different particle sizes and seperations. Consequences on the reaction mechanism are discussed.