Regensburg 2010 – scientific programme

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O: Fachverband Oberflächenphysik

O 4: Heterogeneous catalysis I

O 4.4: Talk

Monday, March 22, 2010, 12:00–12:15, H33

CO oxidation on Au/TiO₂(110) model catalysts - support oxidation state and Au particle size effects — •Menhild Eyrich, Cihan Topkaya, Joachim Bansmann, and R. Jürgen Behm — Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm

Since Haruta [1] discovered the unusual catalytic activity of small Au particles on transition metal oxide supports in the late 1980s, numerous studies were carried out on the catalysts to understand the physical origin of the high activity. Especially for the CO oxidation on TiO₂ supported Au catalysts, the reaction mechanism is still not completely resolved. Analogously to the respective powder catalysts, also the activity of the planar model catalysts strongly depends on the pretreatment of the catalyst and on the size of the Au nanoparticles. Here, we report the results of a study on fully oxidized and reduced planar Au/TiO₂ model catalysts. For each model system, the reaction rates for different Au nanoparticle sizes were determined. The results will be compared to other Au/TiO₂ catalysts and possible reasons for the strong influence of the Au nanoparticle size and the oxidation state of the support on the catalytic activity will be discussed.

[1]M. Haruta, N. Yamada, T. Kobayashi, S. Iijima, J. Catal. 115 (1989), 301-309.