A STUDY OF THE PREPARATION PROCEDURES OF SULFATED ZIRCONIA PREPARED FROM ZIRCONIA GEL - THE EFFECT OF THE PH OF THE MOTHER SOLUTION ON THE ISOMERIZATION ACTIVITY OF N-PENTANE

Solid superacids of sulfated zirconia were prepared by the sulfation o f zirconia gels, which were obtained from mother solutions with differ ent pH values. The gel precipitated at pH = 8 gave the sulfated zircon ia, which showed the highest catalytic activity and selectivity for th e skeletal isomerization of n-pentane. The active superacid was obtain ed with high reproducibility upon heating the mother solution, followe d by washing the precipitate with hot water; this preparation procedur e provided the oxide of small particle size. The catalytic activity of sulfated zirconia could be estimated from the exothermal peak caused by crystallization of the zirconia gel in DTA.