In this paper, we report on the solid superacids, ZrO~2 modified by persulfate, and their activities in n-butane isomerization. The factors affecting their properties, including calcination temperature, impregnation concentration and the conditions for preparing the precursor ZrO~2, are studied. The results indicate that the sample which is prepared by impregnation reverse-dropping-coprecipitated zirconia with 0.25-0.50mol/L persulfate and then calcination at 600- 650℃ shows the highest superacidity. Compared with sulfated zirconia prepared under the same conditions, the activity of n-butane isomerization at 250℃ on persulfated zirconia is twice as high as that on sulfated zirconia because of its more intermediate-strong acid sites and different active sites.

Key words: ZIRCONIUM OXIDE, BUTANE, ISOMERIZATION, SUPERACID