1. EMPI, Institute for Energy and Materials Processes − Reactive Fluids, University of Duisburg-Essen, 47048 Duisburg, Germany
2. Chemical Technology III, University of Duisburg-Essen, 47048 Duisburg, Germany
3. Fritz-Haber-Institut der Max-Planck Gesellschaft, Departments of Physical Chemistry and Inorganic Chemistry, Faradayweg 4-6, 14195 Berlin, Germany
4. Experimental Physics, Faculty of Physics, University of Duisburg-Essen, 47048 Duisburg, Germany
5. CENIDE, Center for Nanointegration, University of Duisburg-Essen, 47048 Duisburg, Germany