Normal Hexane Hydroisomerization Over an Alumina and Yttria Promoted Pt/SO4 2−/ZrO2 Catalyst

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, H2-TPR, and NH3-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 catal...