Immobilization of a thiol-functionalized ionic liquid onto HKUST-1 through thiol compounds as the chemical bridge
Immobilization of a thiol-functionalized ionic liquid onto HKUST-1 through thiol compounds as the chemical bridge
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通过硫醇化合物作为化学桥将硫醇功能化离子液体固定在 HKUST-1 上
DOI：
10.1039/c6ra03317b
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发表时间：
2016-01-01
期刊：
影响因子：
3.9
通讯作者：
Guan, Guofeng
中科院分区：
文献类型：
--
作者：
Chen, Chong;Wu, Zuowang;Guan, Guofeng
以油酸和短链醇为原料，合成了一种新型多相催化剂[HVIm-（CH 2）3SO 3 H]HSO4@HKUST-1（IL@HKUST-1），该催化剂同时具有刘易斯和Bronsted酸中心，可用于油酸和短链醇的酯化反应.采用乙二硫醇对HKUST-1进行化学修饰，然后将含乙烯基的离子液体通过硫醇基团接枝到载体上。采用XRD、N2吸附-脱附、FT-IR、SEM、TG、元素分析、ICP等手段对IL@HKUST-1催化剂进行了表征。结果表明，HKUST-1具有典型的微孔结构，巯基被引入到载体的孔道中。通过乙烯基与巯基的反应，成功地将离子液体以化学共价键的形式固定在SH-HKUST-1上。将该催化剂应用于油酸与乙醇的酯化反应，确定了最佳工艺条件：n（乙醇）：n（油酸）= 12：1，催化剂用量为油酸质量的15%，反应时间4 h，反应温度90 °C。在此条件下，油酸的转化率为92.1%。催化剂循环使用5次后，转化率没有明显下降，显示出一定的稳定性和良好的重复使用性。该催化剂对油酸与其它短链醇的酯化反应也表现出较高的催化活性。
A novel heterogeneous catalyst [HVIm-(CH2)3SO3H]HSO4@HKUST-1 (IL@HKUST-1), with both Lewis and Bronsted acid sites, was developed for the esterification of oleic acid with short-chain alcohols. HKUST-1 was chemically modified with ethanedithiol, and the vinyl-containing ionic liquid was then grafted onto the carrier through thiol groups. The catalyst IL@HKUST-1 was characterized by XRD, N2 adsorption–desorption, FT-IR, SEM, TG, elemental analysis, and ICP. The results proved that HKUST-1 had typical microporous structure, and the thiol groups were incorporated into the channels of the carrier. Through the reaction of vinyl and thiol, the ionic liquid was successfully immobilized onto SH-HKUST-1 by chemical covalent bonds. The catalyst was applied in the esterification of oleic acid with ethanol, and the optimal conditions were determined as follows: molar ratio of ethanol to oleic acid 12:1, catalyst amount 15 wt% (based on oleic acid), reaction time 4 h, and reaction temperature 90 °C. Under the conditions, the conversion of oleic acid was 92.1%. After 5 times of recycling, there was no significant decrease in conversion, showing a certain stability and good reusability of the catalyst. The catalyst also exhibited high catalytic activity in esterification of oleic acid with other short-chain alcohols.