During and before my diploma thesis I worked in Prof. Ganteför's group at the University of Konstanz. In our experiments, we investigated catalytical effects of small gold clusters on carbon monoxide.

Clusters by definition are only a few atoms, lets say 3 to 10000. During my thesis we investigated gold clusters that ranged up to 10 atoms. In this regime, every single atom counts. That means with every atom added or removed from the cluster particle, properties of the material may change dramatically. This leads to the interesting possibility to tailor new materials with selected properties.

The oxidation behaviour of small gold clusters in the gas phase is well known and shows an even-odd alternation; meaning that all clusters with an even number of gold atoms react with oxygen. On the other hand the odd numbered clusters do not show such a reaction. Consequently, even numbered gold clusters can be used to act as a catalyst.

For technical usage these clusters have to be deposited on a substrate. Unfortunately, the influence of the substrate changes the oxidation ability. So the interesting question was to find a similar behaviour for clusters deposited on a substrate.

For small gold clusters deposited on SiO2-Si-Wafers a weak even-odd alternation was found. This result helped to better understand the mechanism of the interaction of substrate and metal cluster.

In June 2006, I finished the thesis and received my diploma from the University of Konstanz. You can download the thesis in two versions, in print (for duplex printing) and online.
Print Version
Online Version


I was involved in several publications during my work:
Oxidation of Au nanoparticles on HOPG using atomic oxygen
Dong Chan Lim, Ignacio Lopez-Salido, Rainer Dietsche, Moritz Bubek and Young Dok Kim
Surface Science 600, 507 (2006)
  • Size-selectivity in the oxidation behaviors of Au nanoparticles
    Dong Chan Lim, Ignacio Lopez-Salido, Rainer Dietsche, Moritz Bubek and Young Dok Kim
    Angewandte Chemie 118, 2473 (2006)
  • Oxidation and reduction of mass-selected Au clusters (Au_n, n=2-10) deposited on SiO2/Si
    Dong Chan Lim, Rainer Dietsche, Moritz Bubek, Gerd Ganteför and Young Dok Kim
    ChemPhysChem 7, 1909 (2006)
  • Oxidation of Au nanoparticles and clusters on HOPG or SiO2
    M. Bubek, R. Dietsche, D.C. Lim, I. Lopez-Salido, Y.D. Kim and G. Ganteför
    Poster for DPG Meeting 2006, Dresden
    Poster as pdf
  • Chemistry of mass-selected Au clusters deposited on sputter-damaged HOPG surface: The unique properties of Au8 clusters
    Dong Chan Lim, Rainer Dietsche, Moritz Bubek, Thorsten Ketterer, Gerd Ganteför, Young Dok Kim
    Chemical Physics Letters 439, 364 (2007)
  • Comparison of electronic structures of mass-selected Ag clusters and thermally grown Ag islands on sputter-damaged graphite surfaces
    Rainer Dietsche, Dong Chan Lim, Moritz Bubek, Ignacio Lopez-Salido, Gerd Ganteför, Young Dok Kim
    Applied Physics A 90, 395 (2008)
  • The thesis:
    Photoelektronenspektroskopie an Metallclustern
    Moritz Bubek
    June 2006
    PDF print version
    PDF online version
  • different posters for various conferences:
    Clustertreffen 2005
    SFB Meeting Kloster Irsee, 2005
    Hydrogen Workshop, Bad Honnef , 2005