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O: Fachverband Oberflächenphysik

O 73: Symposium: Bimetallic Nanosystems: Tuning Physical and Chemical Properties II (Invited Speakers: André Fielicke, Thomas Risse, Jürgen Behm)

O 73.3: Hauptvortrag (ohne Erstattung)

Donnerstag, 28. Februar 2008, 15:00–15:30, MA 005

Bimetallic Catalysis - Fundamental effects studied on well defined model systems — •R. Jürgen Behm — Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm

Bimetallic catalysts are well known to often exhibit a significantly better performance, in activity and/or selectivity, than the respective components [1]. Based on catalytic measurements using catalysts with varying composition, different electronic and geometric effects were introduced to explain there observations [2]. Direct proof, however, was hardly possible because of the mostly unknown surface composition of the catalyst particles. Adsorption and reaction studies on bimetallic surfaces with well-defined, varied distribution of surface atoms, as identified, e.g., by high resolution scanning tunneling microscopy with chemical contrast, allow for the first time to directly identify and separate these effects [3]. Furthermore, they provide a solid basis for comparison with theory [3]. The potential of combined experimental and theoretical studies is demonstrated using different adsorption/reaction systems as example.

1. J.H. Sinfelt, Surf. Sci. 500 (2002) 923.

2. W.M.H. Sachtler, in Handbook of Heterogeneous Catalysis, G. Ertl, H. Knözinger, and J. Weitkamp, Eds. (VCH-Wiley, Weinheim, 1997), Vol. 3.

3. M. Ruff, N. Takehiro, P. Liu, J.K. Norskov, R.J. Behm, Chem. Phys. Chem. 8 (2007) 2068.