PSZA) catalysts were prepared by extruding sulfated hydroxide zirconium with SB powder. The n-hexane hydroisomerization reaction was performed in a continuous flow fixed-bed reactor. Isomerization activities under varying pretreatment parameters (including catalyst storage time before use, activating temperature, and reduction temperature) and reaction conditions (including reaction temperature, space velocity, and the molar ratio of hydrogen to n-hexane) were investigated. The results indicated the optimum pretreatment conditions for the PSZA catalyst is as follows: five days of storage, 350 ı C of the activation temperature, and 250 ı C of the reduction temperature. In addition, the optimum reaction conditions contained the reaction temperature ranging from 200 to 210 ı C, space velocity of 1 hr 1 , and hydrogen to hexane mole ratio of 5.

Sulfated zirconia was promoted with alumina and yttria in order to improve catalyst isomerization behaviors. The n-hexane hydroisomerization reaction was carried out in a continuous flow fixed-bed reactor for 80 h on stream to evaluate catalyst reaction stability. The catalyst was characterized by XRD, TGA, H 2 -TPR, and NH 3 -TPD technologies in order to investigate the crystalline structure, sulfur content, reduction behavior, and acidity of the catalyst. It was proved that the addition of alumina and yttria obviously increased the sulfur content on the fresh catalyst and also markedly stabilized the sulfur species on the used catalysts. Thus, the modified catalyst possessed the better stable activity and selectivity although the addition of promoter could not enhance the isomerization activity. The crystalline structure of sulfated zirconia, acidity, and sulfur content only showed a limited influence on the isomerization activity of the catalyst. This work would have potential use to prepare an ideal catalyst for a commercial alkane hydroisomerization unit.