1. Centre for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, 1033 Blindern, 0315, Oslo, Norway
2. Department of Chemistry, NIS Center and INSTM Reference Center, University of Turin, 10125 Turin, Via P. Giuria 7, Italy
3. Topsoe A/S, Haldor Topsøes Allé 1, DK-2800 Kgs. Lyngby, Denmark