Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3)固体超强酸催化剂的制备及其异构化性能评价

Preparation and Isomerization Performance Evaluation of Pt-SO_(2)-4/ZrO_(2)-WO_(3) Solid Superacid Catalyst

在Pt-SO_(4)^(2-)/ZrO_(2)固体超强酸中引入WO_(3)制备了Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3)固体超强酸催化剂,采用N 2吸附-脱附、XRD、TPD、TPR和Py-IR等手段对所制备催化剂进行了分析表征;在5 mL连续固定床反应装置上,考察了WO_(3)含量对Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3)催化剂作用下正己烷临氢异构化反应活性的影响。结果表明:WO_(3)的引入能够显著调节Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3)催化剂中四方晶相ZrO_(2)含量、比表面积、孔体积、平均孔径和酸量等,使暴露在催化剂表面的活性中心明显增加;在反应温度240℃、反应压力2.0 MPa、体积空速1.0 h-1、氢气/正己烷体积比600的条件下,WO_(3)质量分数16%的Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3)催化剂的异构化活性最高,正己烷转化率为82.27%,异构化率为81.32%,二甲基丁烷选择性为34.28%。

Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3) solid superacid catalysts were prepared by introducing WO_(3) into Pt-SO_(4)^(2-)/ZrO_(2) solid superacids,and the catalysts were characterized by N 2 adsorption-desorption,XRD,TPD,TPR and Py-IR;meanwhile,the effect of WO_(3) content on the reactivity of n-hexane hydroisomerization under the action of Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3) catalyst was investigated in a 5 mL continuous fixed bed reactor.The results show that the introduction of WO_(3) can significantly adjust the tetragonal ZrO_(2)content,specific surface area,pore volume,average pore diameter and acid amount in Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3) catalyst;the active centers exposed on the surface of the catalyst increase significantly.Under the reaction temperature of 240℃,reaction pressure of 2.0 MPa,volume space velocity of 1.0 h-1,hydrogen to n-hexane volume ratio of 600,Pt-SO_(4)^(2-)/ZrO_(2)-WO_(3) catalyst with the WO_(3) mass fraction of 16%has the highest isomerization activity:the conversion of n-hexane,isomerization rate and dimethylbutane selectivity are 82.27%,81.32%and 34.28%,respectively.