SO_4^(2-)/SiO_2-ZrO_2固体超强酸催化乳酸乙酯的合成研究

Study on synthesis of ethyl lactate utilizing SO_4^(2-)/ SiO_2-ZrO_2 as catalyst

目的研究自制固体超强酸对乳酸乙酯的合成反应的催化效果,寻求乳酸乙酯的最佳合成条件。方法采用溶胶凝胶法制得SiO2-ZrO2基质材料,然后将其通过浸渍法制备了SO42-/SiO2-ZrO2固体超强酸,对SO42-/SiO2-ZrO2固体超强酸催化乳酸乙酯的合成反应进行了研究。结果SO42-/SiO2-ZrO2固体超强酸催化乳酸乙酯的合成反应适宜的反应条件为:预焙烧温度为200℃,浸泡硫酸浓度为1.0 mol/L,硅锆摩尔比为15,焙烧温度为500℃,醇酸比为3时,酯化率可达92.7%。XRD对固体超强酸的分析结果表明,其中SiO2是三斜晶型,ZrO2是四方晶型。结论自制的SO42-/SiO2-ZrO2固体超强酸的对乳酸乙酯的合成反应具有良好的催化效果,适宜推广应用。

Aim SO4^2-/SiO2-ZrO2 solid superacids as catalyst is used to synthesize ethyl lactate with ethynol and lactic acid, the optimal conditions of the synthesis reaction were determined. Meth~ ods The SiO2-ZrO2 composites were prepared via the sol-gel process, the SiO2-ZrO2 composites were applied to prepare the SO4^2-/SiO2-ZrO2 solid superacids, the synthesis of ethyl lactate with ethynol and lactic acid as reactant and the SO4^2-/SiO2-ZrO2 solid superacid as catalyst had been studied. Results The SiO2-ZrO2 composites were calcined at 200℃ prior to sulfating, the concentration of sulfuric acid was 1.0 mol/L ,the molar ratio of Si and Zr was 15, the calcination temperature was 500℃, the molar ratio of ethynol and lactic acid is 3/1, the yield of the ester could reach 92.7%. Conclusion SO4^2-/SiO2-ZrO2 solid superacids, which were prepared via the sol-gel process, are good catalyst for synthesizing ethyl lactate with ethynol and lactic acid.