ONE-STEP SOL-GEL SYNTHESIS OF SULFATED-ZIRCONIA CATALYSTS

Sulfated-zirconia catalysts were prepared by a one-step sol-gel method . Two different protocols were studied in which sulfuric acid is intro duced either with the hydrolysis water, or in the zirconium alkoxide s olution in n-propanol. After calcination at 923 K these two materials were compared with sulfated-zirconia prepared in two steps by post-sul fation of zirconium hydroxide obtained either by the sol-gel method or by precipitation of inorganic salts. The sulfated-zirconias prepared by the one-step protocol are the most active catalysts for the hydroco nversion of n-hexane. Moreover, the sample prepared by adding sulfuric acid through the hydrolysis water exhibits different textural propert ies and enhanced activity for n-hexane conversion. These different beh aviours cannot be explained by the sulfur content.