1. Centre for Surface Chemistry and Catalysis, K.U. Leuven, Kasteelpark Arenberg 23, B-3001 Heverlee, Belgium, Institut Lavoisier, Université de Versailles St. Quentin en Yvelines, 45 avenue des Etats-Unis, F-78035 Versailles, France, Centre de Biochimie Structurale, 29 rue de Navacelles, F-34090 Montpellier, France, IESL-FORTH, P.O. Box 1527, GR-711 10 Heraklion, Greece, Department of Chemical Engineering, K.U. Leuven, Willem de Croylaan 46, B-3001 Heverlee, Belgium, and Department of Chemistry, K.U....