1. Univ. Lille; CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181-UCCS-Unité de Catalyse et Chimie du Solide, F-; 59000 Lille France
2. Department of Chemical Engineering; Federal University of Rio Grande do Sul-UFRGS; Rua Luiz Englert, s/n° 90040-040 Porto Alegre/RS Brazil
3. Lennard-Jones Laboratories; Keele University; Staffordshire ST5 5BG UK
4. IPCMS; Université de Strasbourg; 23, rue du Loess BP 43, F- 67034 Strasbourg France