H-ZSM-5/ZrO2/SO42-固体酸复合催化剂的表征及烷基化反应性能

将H-ZSM-5分子筛与Zr基氧化物进行复合，经过硫酸处理后，合成H-ZSM-5/wZrO₂/SO^2-₄(w分别为40%、50%、60%)固体酸复合催化剂。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)及NH₃程序升温吸附-脱附(NH₃-TPD)等分析手段对催化剂进行表征，并在固定床反应装置上考察了不同催化剂催化异丁烯-异丁烷烷基化反应性能。结果表明：经过硫酸处理后，催化剂中单斜晶相m-ZrO₂转化为对烷基化反应有利的四方晶相t-ZrO₂；H-ZSM-5/50%ZrO₂/ SO^2-₄固体酸复合催化剂具有最高的总酸量和中强酸酸量，中强酸是催化异丁烯 异丁烷烷基化反应的控制因素；同时也证实了H-ZSM-5和ZrO₂ 2种组分在复合催化剂中具有协同作用。在压力为1.4 MPa、温度为80 ℃、原料进料体积流速为2.0 mL/h、载气体积流速为1200 mL/h、反应时间为120 min的条件下，H-ZSM-5/50% ZrO₂/SO^2-₄复合催化剂作用下产物C8选择性最高为83.0%，异丁烯最高转化率为94.1%，反应稳定后异丁烯转化率保持在55.2%，收率保持在45.8%，说明H-ZSM-5/50% ZrO₂/SO^2-₄固体酸复合催化剂具有良好的催化反应性能。

Characterization and Alkylation Reaction Performance of H-ZSM-5/ZrO2/SO42- Solid Acid Composite Catalyst

H-ZSM-5/wZrO₂/SO^2-₄ (w=40%, 50% and 60%, respectively) solid acid composite catalyst was synthesized by compounding H-ZSM-5 zeolite with Zr-based oxide and treating with sulfuric acid. The catalyst was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and NH3 temperature programmed desorption (NH₃-TPD), and the isobutene-isobutane alkylation reaction performance of different catalysts was investigated in a fixed bed reactor. The results show that the monoclinic m-ZrO₂ in the catalyst is converted into the t-ZrO₂ which is beneficial to alkylation reaction after sulfuric acid treatment; H-ZSM-5/50% ZrO₂/SO^2-₄ solid acid composite catalyst has the highest total acid content and moderately strong acid content, and the latter is the controlling factor for catalyzing isobutene-isobutane alkylation reaction; it has also been confirmed that the two components of H-ZSM-5 and ZrO₂ have a synergistic effect in the composite catalyst. When the pressure is 1.4 MPa, temperature is 80 ℃, feed volume flow rate of raw materials is 2.0 mL/h, carrier gas volume flow rate is 1200 mL/h and reaction time is 120 min, H-ZSM-5/50% ZrO₂/SO^2-₄ composite catalyst has the highest selectivity for C₈ up to 83.0%, the highest conversion rate of isobutene is 94.1%, the conversion rate of isobutene is 55.2% after stable reaction, and the yield remains at 45.8%, indicating that H-ZSM-5/50% ZrO₂/SO^2-₄ solid acid composite catalyst has a good catalytic performance.