Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 44: Poster Session II (Semiconductors; Oxides and Insulators: Adsorption, Clean Surfaces, Epitaxy and Growth; Surface Chemical Reactions and Heterogeneous Catalysis; Surface or Interface Magnetism; Solid-Liquid Interfaces; Organic, Polymeric, Biomolecular Films; Particles and Clusters; Methods: Atomic and Electronic Structure; Time-resolved Spectroscopies)
O 44.38: Poster
Mittwoch, 28. März 2007, 17:00–19:30, Poster C
GISAXS studies of micellar supported Au nanoparticles on TiO2 — •Nicole Jeutter1, Didier Wermeille1, Joachim Bansmann2, Stefan Kielbassa2, Christine Fix2, Ulf Wiedwald3, Hans-Gerd Boyen3, and Paul Ziemann3 — 1E.S.R.F. , 6 Rue Jules Horowitz, 38000 Grenoble, France — 2Institute for Surface Chemistry and Catalysis, Ulm University, D- 89069 Ulm — 3Institute of Solid State Physics, Ulm University , D- 89069 Ulm
Metal oxide supported gold catalysts have attracted considerable attention because of their surprising activity in a number of reactions such as low temperature CO oxidation [1]. The activity of catalysts might be closely related to the morphology and shape changes of the catalysts under different gas environments. Grazing Incidence Small Angle Scattering (GISAXS) experiments can monitor the morphology evolution in-situ and provide the possibility to determine the reaction parameter when shape changes occur.
Au nanoparticles of a nominate thickness of 12 nm have been deposited on a fully oxidized TiO2 (110) substrate by micellar technique. The characterization of the average size and shape of the catalysts in air before and after annealing to 400∘C has been carried out with GISAXS.
First results show that, before the annealing treatment, the average particle to particle distance can be clearly seen in GISAXS. After the annealing procedure the correlation maxima in the GISAXS pattern are broader and weaker than before.
[1] M.Haruta et al, J.Cat.144 (1993) 175