1. CRPP-UMR CNRS 5031; Université de Bordeaux; 115 Avenue Albert Schweitzer 33600 Pessac France
2. IFP énergies nouvelles - Lyon; Direction Catalyse et Séparation; BP-3 69360 Solaize France
3. Department of Civil and Environmental Engineering; Massachusetts Institute of Technology; 77 Mass. Av. Cambridge MA 02139 USA