Aluminum-promoted sulfated zirconia （ASZ） catalyst was prepared by impregnation of zirconium hydroxide with aqueous Al2（SO4）3 followed by calcinations. The characterization of these samples was carried out with various techniques such as X-ray powder diffraction （XRD）, N2 adsorption （BET）, NH3 temperature-programmed desorption （NH3-TPD）. The results indicated that the addition of aluminum has an effect on acid properties of the catalysts. Isomerization of n-pentane was carried out at 2.0 MP, WHSV 0.5 and H2/pentane molar ration of 4. In comparison to sulfated zirconia （SZ）, ASZ catalyst exhibited high catalytic activity and stability at low reaction temperature. In particular, when the reaction temperature was 120 ℃, the n-pentane conversion over ASZ remains at 80%, which is closed to its equilibrium conversion after running on stream for 6 h.
