Affiliation: | aLaboratoire de Chimie des Matériaux et Catalyse, Faculté des Sciences de Tunis, Campus Universitaire, 2092 El Manar, Tunis, Tunisia bInstitut de Recherches sur la Catalyse et l’Environnement du CNRS, 2, Avenue Albert Einstein, 69626 Villeurbanne Cedex, France |
Abstract: | Silica supported sulfated zirconia catalysts were synthesized via a new method by grafting sulfated zirconia on the surface of a silica aerogel previously prepared. The main parameters studied in this work were the S/Zr, Zr/Si molar ratios and the support nature. The synthesized solids were characterized using XRD, N2 physisorption at 77 K, TG-DTA/SM, sulfur chemical analysis and adsorption–desorption of pyridine followed by infrared spectroscopy. These solids were tested in the n-hexane isomerization reaction. Two types of mesopores were observed on the silica aerogel. This mesoporosity was affected depending on the preparation parameters. The increase of the Zr/Si molar ratio induces the decrease of the size of zirconia particles deposed on the support. In this case, appreciable amounts of sulfur are retained with the presence of a relatively strong Brönsted and Lewis acid sites on the catalyst surface. A high density of Brönsted sites seems to be interesting in the n-hexane isomerization reaction. |