Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)

O 60.126: Poster

Mittwoch, 16. März 2011, 17:30–21:00, P4

CO oxidation reaction on thin mesoporous Au/TiO₂ layers — •Matthias Roos¹, Dominique Böcking², Kwabena Offeh Gyimah¹, Gabriela Kucerova¹, Joachim Bansmann¹, Nicola Hüsing^2,3, and R. Jürgen Behm¹ — ¹Institute of Surface Chemistry and Catalysis, Ulm University, D-89069, Germany — ²Institut für Anorganische Chemie II, Ulm University, D-89069, Germany — ³Abteilung Materialchemie, Universität Salzburg, A-5020, Austria

The catalytic properties of thin homogeneous layers of mesoporous Au/TiO₂ [1] deposited onto silicon substrates to study the CO oxidation reaction was investigated. The mesoporous TiO₂ layers are fabricated using a sol-gel process followed by the precipitation-deposition of Au nanoparticles. The measurements on the catalytic activity were performed in a vacuum system using a quadrupole mass spectrometer which allows to collect the reaction gases very close to a specific region on the surface [2]. Using this setup, the activation energy and the reaction orders of CO and O₂ were measured and compared to respective measurements on planar Au/TiO₂(110) model catalysts and standard Au/TiO2 powder catalysts. Furthermore, the catalytic stability and the deactivation behaviour of the mesoporous Au/TiO₂ films was studied. To test the accessibility by reaction gases of deeper lying regions within the catalytically active films, the thickness of the TiO₂ layers was varied for different measurements.

[1] Y. Denkwitz et al., Appl. Cat. B 91 (2009) 470

[2] M. Roos et al., J. Chem. Phys. 133 (2010) 094504