催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (10): 910-914.

• 研究论文 • 上一篇    下一篇

MCM-41分子筛的表面修饰及其催化合成乙酸异戊酯

陈静1,韩梅1,2,李桂云1,王锦堂1   

  1. 1 南京工业大学理学院应用化学系, 江苏南京 210009; 2 重庆科技学院化学与生物工程学院, 重庆 400050
  • 收稿日期:2007-10-25 出版日期:2007-10-25 发布日期:2011-10-28

Surface Modification of MCM-41 Molecular Sieve and Its Catalytic Performance for Synthesis of Iso-amyl Acetate

CHEN Jing1, HAN Mei1,2, LI Guiyun1, WANG Jintang1*   

  1. 1 Department of Applied Chemistry, School of Science, Nanjing University of Technology, Nanjing 210009, Jiangsu, China;2 School of Chemistry and Bioengineering, Chongqing University of Science and Technology, Chongqing 400050, China
  • Received:2007-10-25 Online:2007-10-25 Published:2011-10-28

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1053

被引次数

41

摘要： 通过后合成处理将苄基、三甲基硅烷基和磺酸基接枝到MCM-41分子筛上,制备了一种新型的有机-无机杂化S-B-MCM-41催化剂. 采用X射线衍射、低温N2吸附-脱附和酸碱滴定对样品的结构和质子酸量进行了表征和测定. 结果表明, S-B-MCM-41催化剂较好地保持了MCM-41分子筛的介孔结构, BET比表面积高达798 m2/g, 质子酸量为4.0 mmol/g. 将S-B-MCM-41催化剂用于乙酸与异戊醇合成乙酸异戊酯的反应,考察了各种反应条件对酯化率的影响. 在乙酸用量为0.1 mol, 异戊醇用量为0.15 mol, 催化剂用量为0.2 g, 带水剂甲苯为15 ml, 反应温度为110～125 ℃, 反应时间为2 h的优化条件下S-B-MCM-41上的酯化率可达99%以上; 而MCM-41分子筛上的酯化率仅为54%. 经3次重复使用后, S-B-MCM-41催化剂上的酯化率依然保持在90%以上. 初步探讨了S-B-MCM-41催化剂催化合成乙酸异戊酯的反应机理.

关键词: MCM-41分子筛, 表面修饰, 苯甲醇, 三甲基氯硅烷, 氯磺酸, 乙酸, 异戊醇, 乙酸异戊酯

Abstract: MCM-41 molecular sieve was synthesized by the sol-gel method and functionalized with benzyl sulphonic acid and trimethylchlorosilane using a post-synthetic procedure. The organic groups were covalently bonded to the surface of MCM-41 by etherification ofSi-OHand thus a new S-B-MCM-41 catalyst was prepared. The structure and Brnsted acid amount of S-B-MCM-41 catalyst were characterized by XRD, N2 adsorption-desorption, and acid-base titration. The results showed that the mesoporous structure of MCM-41 was maintained in the S-B-MCM-41 catalyst with a BET surface area of 798 m2/g and acid capacity of 4.0 mmol/g. The synthesis of iso-amyl acetate from acetic acid and iso-amyl alcohol over S-B-MCM-41 catalyst and its catalytic performance were investigated. Under the optimum conditions of acetic acid 0.1 mol, iso-amyl alcohol 0.15 mol, catalyst0.2 g, water-entrainer toluene 15 ml, reaction temperature 110-125 ℃, and reaction time2 h, the esterification fraction was over 99%. By comparison, the MCM-41 molecular sieve only had an esterification fraction of 54% under the same conditions. After three times of repeated use, the esterification fraction above 90% still maintained over S-B-MCM-41. The reaction mechanism for the esterification was discussed.

Key words: MCM-41 molecular sieve, surface modification, benzoic alcohol, trimethylchlorosilane, chlorosulphonic acid, acetic acid, iso-amyl alcohol, iso-amyl acetate