1. Laboratory of Industrial Chemistry, Ruhr University Bochum, D-44780 Bochum, Germany
2. Department of Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany
3. University of Duisburg-Essen, D-45141 Essen, Germany
4. Institute of Inorganic Chemistry, Christian-Albrechts-Universität zu Kiel, D-24118 Kiel, Germany
5. Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany