介孔分子筛Al-MCM-41制备及催化合成二芳基乙烷

以硅酸钠为硅源、硫酸铝为铝源、CTAB为模板剂,采用水热法合成了骨架负载型固体酸Al-MCM-41介孔分子筛催化剂,并通过X射线衍射(XRD)、扫描电子显微镜(SEM)和红外(IR)方法对其进行了表征,同时研究了该催化剂在二芳基乙烷合成反应中的催化性能. 考察了各种反应因素的影响,确定其最佳合成条件为:原料m(苯乙烯)∶m(二甲苯)=1∶7.5,催化剂用量为1%(总投料质量分数),反应时间为3 h,反应温度为140 ℃,产率可达87.1%,比传统催化剂浓硫酸提高了17%. 研究结果表明,该催化剂是替代液体酸合成二芳基乙烷的理想固体酸催化剂.

Preparation of Mesoporous Molecular Sieve Al-MCM-41 and Its Catalytic Activity for Synthesis of Diphenylethane

Al-MCM-41 mesoporous sieves were synthesized by using Na2SiO3 as silica source, Al2(SO4)3 as aluminum source, and cetyltrimethylammonium bromide(CTAB) as template under hydrothermal condition. The Al-MCM-41 mesoporous sieves were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and infrared spectroscopy(IR). The synthesis of diphenylethane over Al-MCM-41 catalyst and its catalytic performance were investigated. The results show that the optimal conditions were the mass percent of catalyst was 1% of the feed stock;molar ratio of xylene to styrene was 7.5∶1;reaction temperature was 140 ℃ and reaction time 3 h. The yield of diphenylethane under such conditions was about 87.1%, which was 17% higher than the yield when traditional sulfuric acid was used as catalyst. The results show that Al-MCM-41 is a promising solid acid catalyst for the synthesis of diphenylethylane instead of liquid acid.