Effect of Al Contents on the Isomerization Performance of Solid Superacid Pt-S_2O_8~(2-)/ZrO_2-Al_2O_3

High catalytic activity and stability Pt-S2O82 -/ZrO2-Al2O3 solid superacid catalysts were prepared by simultaneously introducing the appropriate amount of Pt and Al2O3 into S2O28 -/ZrO2 catalyst. The effects of Al contents on the performance of catalysts was studied by n-pentane isomerization as a probe reaction and the catalysts were characterized by XRD,BET,FTIR,TPR,TG-DTA,NH3-TPD and ICP etc. The results show that Al can delay crystallization temperature of the ZrO2,inhibit the decomposition of sulfur. Al can also increase the surface area of catalyst,strengthen the combination between S and O key,improve the redox performance of the catalyst and increase acid strength and total acid of catalyst. With the mass fraction of Al2O3 is 2. 5% ,the catalytic activity of Pt-S2O82 -/ZrO2-Al2O3 solid superacid catalysts is the best. The isopentane yield can reach 66. 2% and the selective is larger than 98. 2% .