Düsseldorf 2007 – wissenschaftliches Programm

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MS: Fachverband Massenspektrometrie

MS 7: Poster

MS 7.7: Poster

Mittwoch, 21. März 2007, 16:30–18:30, Poster A

The effect of gold doping on the reactivity of free silver clusters: Comparison of Ag3+ and Ag2Au+ — •Denisia Popolan, Mihai Vaida, and Thorsten Bernhardt — Universität Ulm, Institut für Oberflächenchemie und Katalyse, Ulm, Germany

The chemistry of noble metal clusters was intensively studied in recent years. This is due to their fascinating properties acting as promising low temperature catalytic materials. However, the surprising reactive behavior is still far from being completely understood. Free gas phase clusters investigated by mass spectrometric methods might help to shed light on the reaction mechanisms and size effects in reactivity. Besides the pure free gold and silver clusters also mixed silver-gold clusters have been investigated. Insight into the active role of gold as a catalyst and into the possibilities of doping effects using gold atoms will help in the comprehension of the reactive properties of bimetallic clusters. Our investigations aim to elucidate the influence on the reactivity when silver atoms in Agn clusters are replaced atom by atom. In this contribution results on the reactivity of Ag3+ with carbon monoxide at temperatures between 100 and 300 K are presented. The effect of introducing one gold atom on the chemical reaction kinetics is studied by comparison with the cluster Ag2Au+. The investigations are performed in a low energy ion beam apparatus consisting of a sputter cluster ion source and of a temperature variable octopole ion trap inserted into a multiple quadrupole mass spectrometer arrangement.