Berlin 2001 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MO: Molekülphysik
MO 1: Posters Monday: Clusters, Fullerenes and Nanotubes
MO 1.20: Poster
Monday, April 2, 2001, 12:30–15:00, AT3
Laser depletion during gold cluster anion reactions in an octopole ion trap — •Maryam Elijazyfer1, Liana D. Socaciu1, Jan Hagen1, Ueli Heiz2, Thorsten M. Bernhardt1, and Ludger Wöste1 — 1Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee 14, D-14195 Berlin, Germany — 2Ecole Polytechnique Federale de Lausanne, Institut de Physique Experimentale, CH-1015 Lausanne, Switzerland
Small supported gold clusters have been found to efficiently catalyze the oxidation of carbon monoxide even at cryogenic temperatures [1]. The presented investigations aim to model this catalytic activity of gold particles with very small gas phase clusters. The clusters are produced in a sputtering ion source (CORDIS), mass selected in a quadrupole mass spectrometer and transferred into a variable temperature octopole ion trap. This octopole trap contains a gas mixture of helium, oxygen and carbon monoxide. The ionic reaction products are finally measured as a function of storage time by using a second quadrupole mass spectrometer. We find that at temperatures below 250 K already gold dimer and trimer anions show reaction products containing both, O2 and CO adsorbates. In order to further characterize the structure of the adsorbate complexes, we perform laser depletion spectroscopy and monitor the product concentrations as a function of reaction time and laser wavelength. [1] M. Haruta, Catalysis Today, 36, 153-166, 1997