Isomerization and cracking reactions of branched octanes on sulfated zirconia Original Research Article

The competitive isomerization and cracking reactions of branched octanes at 373 K on sulfated zirconia were studied in relation with the product distribution expected from bimolecular pathway for n- to isobutane isomerization. The high selectivity in isoalkanes can be rationalized by a rapid equilibration of the initial octyl ions followed by cracking of those ions which generate t-butyl and t-pentyl cations before hydride transfer. However, the overall product distribution suggests a more complex scheme with substantial participation of higher molecular weight intermediates. Mechanistic routes are discussed.