1. Inorganic Chemistry and Catalysis GroupDebye Institute for Nanomaterials ScienceUtrecht University Universiteitsweg 99 3584CG Utrecht The Netherlands
2. Laboratory for Inorganic Materials and CatalysisDepartment of Chemical Engineering and ChemistryEindhoven University of Technology P. O. Box 513, 5600 MB Eindhoven The Netherlands
3. Center for Nanophase Materials SciencesOak Ridge National Laboratory 1 Bethel Valley Rd. PO Box 2008 Oak Ridge Tennessee 37831 USA