1. Faculty of Chemistry, Department of Chemical Metallurgy, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland, and Mecanique Energetique, Ecole Polytechnique, Technopôle de Chateau-Gombert, 5 rue Enrico Fermi, 13453 Marseille Cedex 13, France