Highly active superacids of Mn-, Fe-, and Al-sulfated ZrO2'S for the isomerization of butane to isobutane were obtained by exposing zirconia gel to aqueous solutions of 0.05 M MnSO4, 0.25 M FeSO4, and 0.5 M Al-2(SO4)(3) followed by calcining in air at 700, 600, and 675degreesC, respectively. The catalysts were much more active than the superacid of sulfated zirconia, the temperature difference to show the same conversion (20%) between the catalysts and sulfated zirconia being 85, 77 and 85degreesC for the Mn-, Fe-, and Al-catalysts, respectively.