n-Butane and n-pentane isomerization over mesoporous and conventional sulfated zirconia catalysts

Activity results for n-butane and n-pentane isomerization activity on a mes oporous and conventional sulfated zirconia are presented as a function of p retreatment and reaction conditions. During both reactions, rapid deactivat ion occurs followed by a low residual activity. The activity is shown to be a strong function of the extent of hydration of the catalyst. Regeneration in oxygen must be followed by a step that results in the rehydration of th e catalyst to recover the original activity. The optimal activities of both a conventional and a mesoporous sulfated zirconia catalysts also depend on the drying procedure used. A two-site model consisting of Lewis and Bronst ed active sites is proposed to explain the two regimes of deactivation obse rved on these catalysts. (C) 2000 Elsevier Science B.V. All rights reserved .