Clusters on Surfaces: Past, present and future experiments
CAMD/CINF seminar by Prof. Ulrich Heiz, Physical Chemistry, Nanocatalysis, Technical University of Munich.
The chemical and physical properties of small clusters on surfaces are dominated by quantum-size effects that govern the electronic spectra of clusters. For clusters with sizes below about 100 atoms strong variations of the electronic spectra with size occur. This opens the possibility to tune the cluster’s properties not only by the elemental composition but also by adjusting the 3rd dimension of the periodic table, which is size. In this presentation past, present and future experiments on clusters on surfaces are presented. Specifically, in the first part of the talk the influence of cluster size on the reverse spill over and the influence of cluster charging on the chemical properties are discussed. An experimental scheme is then presented to measure heats of chemical processes on size-selected clusters. This device may become relevant in the field of chemical sensors. Finally, results of the optical properties of small, supported clusters are presented, which were obtained by cavity ring-down laser spectroscopy.