Al含量对Pt-S2O82-/ZrO2-Al2O3型固体超强酸催化剂异构化性能的影响

通过向S₂O₈^2-/ZrO₂催化剂中同时引入适量的Pt和Al₂O₃, 制备出了具有较高催化性能和高稳定性的Pt-S₂O₈^2-/ZrO₂-Al₂O₃型固体超强酸催化剂. 以正戊烷异构化反应为探针, 考察了Al含量对催化剂的异构化性能的影响, 并采用XRD, BET, FTIR, TPR, TG-DTA, NH₃-TPD和ICP手段对催化剂进行了表征. 结果表明, Al能够延迟ZrO₂的晶化温度, 抑制硫的分解; Al能够增加催化剂的比表面积, 增强硫氧键的结合, 提高催化剂的还原性能, 增加催化剂的酸强度和酸总量. 当Al₂O₃质量分数为2.5%时, Pt-S₂O₈^2-/ZrO₂-Al₂O₃固体超强酸催化剂的催化活性最高, 正戊烷异构化收率可达60.02%, 选择性在98.2％以上.

Effect of Al Contents on the Isomerization Performance of Solid Superacid Pt-S2O2-8/ZrO2-Al2O3

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 S2O82-/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％.