Regensburg 2004 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

SYNP: Functional Nanoparticles

SYNP 2: Functional Nanoparticles - II

SYNP 2.1: Hauptvortrag

Dienstag, 9. März 2004, 11:30–12:00, H1

Deposited Nanoparticles: Models for Heterogeneus Catalysts — •Hans-Joachim Freund — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Department of Chemical Physics, Faradayweg 4-6, D-14195 Berlin, Germany

In an attempt to model heterogeneous and heterogenized homogeneous catalysts, well-ordered thin oxide films of alumina and silica have been prepared onto which metal nanoparticles have been deposited via evaporation of metal from an oven. By controlling the flux of the metal and the surface temperature nanoparticle ensembles with a rather narrow size distribution and well-defined morphology may be grown. These systems are well suited to be investigated applying surface science tools. We report on a variety of properties of such systems including the electronic structure, the adsorption as well as the reactive properties. In particular, size and morphology dependences are studied, both under ultrahigh vacuum as well as under ambient conditions. We show that such systems, to a certain extent, allow us to bridge the gaps between catalysis and surface science. Sum Frequency generation is employed to study vibrational spectra of surfaces species under ambient pressures.