微波辐射稀土复合固体超强酸催化合成草酸二乙酯

Synthesis of Diethyl Oxalate by Catalysis of Rare Earth Composite Solid Superacid under Microwave Radiation

采用微波辐射技术,以稀土复合固体超强酸SO42--TiO2-La3+为酯化反应催化剂合成草酸二乙酯。通过正交实验设计和单因素实验考察了醇酸摩尔比、微波辐射功率、微波辐射时间、催化剂用量等因素对酯化反应的影响。试验结果表明,稀土复合固体超强酸SO42--TiO2-La3+有着良好的催化活性,当草酸用量为0.1mol,醇酸摩尔比为3.2∶1,催化剂用量为反应物总质量的1.2%,微波输出功率为450W,辐射时间为12min,在此优化条件下,反应的酯化率可达97%以上。而且催化剂重复使用6次仍保持较高活性,所得产品无色透明,纯度很高。并用折光率和红外光谱等手段对产品进行了确证。

Diethyl oxalate was synthesized with the catalyst of rare earth composite solid superacid SO42——TiO2-La^3＋ accelerated by microwave irradiation.Effects of molar ratio of ethanol to oxalic acid,microwave power,microwave irradiation time and catalyst dosage on esterification reaction were investigated by using orthogonal design method and single factor experimentation.The results showed that rare earth composite solid superacid SO42——TiO2-La3＋ was an excellent catalyst for synthesizing diethyl oxalate.If the dosage of oxalic acid was 0.1mol,molar ratio of ethanol to oxalic acid was 3.2∶1.0,microwave power was 450W,microwave irradiation time was 12min,the quantity of catalyst was equal to 1.2% by mass of the total feed stock.Under these optimum experimental conditions,the esterification ratio was more than 97%,moreover,the catalyst could be repeatedly used six times without lossing its catalytic activity.The product was colorless and transparent.The product was verified by refractive index testing and IR spectrometry.