1. Laboratory of Inorganic Materials & Catalysis Department of Chemical Engineering and Chemistry Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven Netherlands
2. European Synchrotron Radiation Facility 71 Avenue des Martyrs 38000 Grenoble France
3. Istituto per lo Studio dei Materiali Nanostrutturati (ISMN)-CNR UOS Palermo Via Ugo La Malfa, 153 90146 Palermo Italy