化工学报 ›› 2020, Vol. 71 ›› Issue (4): 1609-1617.DOI: 10.11949/0438-1157.20191177

• 催化、动力学与反应器 • 上一篇    下一篇

[BMIm]Br离子液体辅助HZSM-5催化乙酸环己酯高选择性水解反应

朱林1(),韩威1,李文松1,邬长城2,李芳1,2,薛伟1,2(),王延吉1,2   

  1. 1.河北工业大学化工学院,河北省绿色化工与高效节能重点实验室,天津 300130
    2.天津市本质安全化工技术 重点实验室,天津 300130
  • 收稿日期:2019-10-11 修回日期:2020-01-09 出版日期:2020-04-05 发布日期:2020-04-05
  • 通讯作者: 薛伟
  • 作者简介:朱林(1996—),女,硕士研究生, 1023349009@qq.com
  • 基金资助:
    国家自然科学基金项目(21776057);天津市自然科学基金项目(17JCYBJC20100);河北省留学人员科技活动择优资助项目(CL201605)

Highly selective hydrolyzation of cyclohexyl acetate over HZSM-5 assisted by [BMIm]Br ionic liquid

Lin ZHU1(),Wei HAN1,Wensong LI1,Changcheng WU2,Fang LI1,2,Wei XUE1,2(),Yanji WANG1,2   

  1. 1.Hebei Provincial Key Laboratory of Green Chemical Technology and High Efficient Energy Saving, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
    2.Tianjin Key Laboratory of Chemical Process Safety, Tianjin 300130, China
  • Received:2019-10-11 Revised:2020-01-09 Online:2020-04-05 Published:2020-04-05
  • Contact: Wei XUE

摘要:

为提高HZSM-5催化乙酸环己酯水解反应生成环己醇的选择性,筛选得到了离子液体[BMIm]Br助剂。发现[BMIm]Br可抑制乙酸环己酯热分解副反应的发生,大幅度提高环己醇选择性。并且,[BMIm]Br可与HZSM-5发生离子交换反应,释放出的H+可促进乙酸环己酯水解反应的发生。在优化的条件下,[BMIm]Br辅助HZSM-5催化乙酸环己酯水解反应转化率为87.5%,环己醇选择性为97.3%。考察了[BMIm]Br和HZSM-5的重复使用性。前者具有较好的稳定性,而HZSM-5活性随循环使用的次数增加而下降。这是由于HZSM-5的骨架铝含量在反应中逐渐降低,导致Br?nsted酸中心数量减少,因此其催化活性逐渐降低。

关键词: 环己醇, 乙酸环己酯, 水解, HZSM-5, 离子液体

Abstract:

To improve the selectivity of HZSM-5 to catalyze the hydrolysis reaction of cyclohexyl acetate to cyclohexanol, an ionic liquid [BMIm]Br auxiliary was screened. It was found that [BMIm]Br could inhibit the side-reaction, thermal decomposition of cyclohexyl acetate, and increase the selectivity to cyclohexanol greatly. Moreover, the ion exchange between [BMIm]Br and HZSM-5 could promote the generation of H+, which could accelerate the hydrolyzation of cyclohexyl acetate. Under the optimized reaction conditions, cyclohexyl acetate conversion was 87.5% with 97.3% cyclohexanol selectivity over HZSM-5 assisted by [BMIm]Br. The reusability of [BMIm]Br and HZSM-5 was investigated respectively, and the former exhibited good stability. However, the catalytic activity of HZSM-5 decreased gradually with the recycling times. It was due to the decreasing of framework Al content of HZSM-5 during the reaction, which led to the reduction of Br?nsted acid sites and therefore resulted in the decreased activity.

Key words: cyclohexanol, cyclohexyl acetate, hydrolyzation, HZSM-5, ionic liquid

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