微波促进稀土复合固体超强酸SO_4^(2-)/TiO_2/Sm^(3+)催化合成乙酸环己酯

Synthesis of cyclohexyl acetate catalyzed by rare earth composite solid superacid SO_4^(2-)/TiO_2/Sm^(3+) under microwave irradiation

在微波辐射下,以稀土复合固体超强酸SO42-/TiO2/Sm3+为非均相催化剂,对环己醇与乙酸酐之间的酰化反应进行了研究.重点考察了催化剂用量、醇酐物质的量比、微波功率和辐射时间对乙酸环己酯收率的影响.实验结果表明,衔土复合固体超强酸SO42-/TiO2/Sm3+有着良好的催化活性,当乙酸酐的加入量为0.1 mol,醇酐物质的量比为2.4∶1.0,催化剂用量为反应物总量的1.0%,微波炉功率为385 W,辐射时间15 m in,在此优化条件下,乙酸环己酯收率可达95.3%,且催化剂重复使用6次仍保持较高活性.所得产品无色透明,具有很高的纯度,并对产品进行了折光率和红外光谱的表征.

The acylation of cyclohexanol with acetic anhydride was studied with rare earth composite solid superacid SO4^2-/TiO2/Sm^3＋ as heterogeneous catalyst under microwave irradiation. The effects of different factors such as catalyst dosage, mole ratio of reactants, microwave irradiation power and microwave irradiation time on the yield of cyclohexyl acetate were carefully investigated. The experimental results showed that rare earth composite solid superacid SO4^2-/TiO2/Sm^3＋ exhibited excellently catalytic activity. The best reaction conditions were as follws：when the amount of acetic an-hydride was 0. lmol, the ratio of cyclohexanol to acetic anhydride was 2. 4： 1.0, the dosage of catalyst was 1.0% of the total mass of the reactants,microwave irradiation power 385W and radiation time 15min. Under these conditions, the yield of cyclohexyl acetate could be reach 95.3%. The catalyst could be repeatedly used six times without lossing its catalytic. The product was colorless, transparent and provided with high purity. The product was characterized by refractive index and infrared spectra.