硅胶负载酸性离子液体催化剂的制备及性能

Preparation and Catalytic Performance of Silica Gel Immobilized Acidic Ionic Liquid Catalyst

以硅胶为载体,采用键合接枝法制备负载化 Brnsted 酸性离子液体催化剂[(TESP)MIm]HSO_4/silica gel,利用元素分析、傅立叶变换红外光谱(FT-IR)和热重-差示扫描量热法(TGA-DSC)等方法对催化剂结构进行了表征。结果表明,离子液体[(TESP)MIm]HSO_4负载量为1.503 mmol/g 的负载催化剂具有良好的热稳定性和重复使用性能。将其应用于乙酸和正丁醇的酯化反应,较佳反应条件为96℃,正丁醇0.12 mol.乙酸0.10 mol,环己烷用量6 mL,催化剂用量为反应物总质量的4%,反应3 h 时,酯化率可达99.4%,催化剂重复使用6次后,酯化率仍可达到74.7%。

A novel Bronsted acidic ionic liquid catalyst 3-（-3-triethoxysilylepropyl）-1-methylimidazolium hydrogen sulfate（[（TESP）MIm] HSO4） supporting on silica gel was prepared with covalent bond grafting method and characterized by means of element analysis, Fourier transformed infrared spectroscopy （FT-IR） and thermogravimetric analysis-differential scanning calorimetry （TGA-DSC）. The results showed that the catalyst （[（TESP）MIm] HSO4/silica gel）, Which loaded ionic liquid [（TESP）MIm]HSO4 1. 503 mmol/g, exhibited good thermal stability and repeatability performance. When it was used to catalyze esterification of butanol and acetic acid, the esterification was 99.4% under the optimized reaction conditions. 96 ℃, butanol 0. 12 mol, acetic acid 0. 10 mol, cyclohexane 6 mL, catalyst mass fraction 4% in reaction medium and reaction time 3 h. The esterification could reach 74. 7% after the catalyst was reused 6 times.