分子筛MCM-48负载杂多酸催化合成乳酸丁酯性能研究

Studies on Catalytic Performance of Heteropoly Acid Supported on MCM-48 Molecular Sieve in Synthesis of Butyl Lactate

通过浸渍法分别将磷钨酸、磷钼酸负载于MCM-48分子筛内,制备负载型杂多酸催化剂,并采用傅里叶变换红外光谱(FT-IR)、N2吸附-脱附、X射线衍射(XRD)等方法对负载型催化剂进行表征。将负载型杂多酸催化剂应用于乳酸丁酯合成反应,在催化剂用量及反应温度确定的条件下,考察了正丁醇和乳酸物质的量比、杂多酸负载量、反应时间对酯化率的影响。结果表明,MCM-48分子筛分别负载磷钨酸和磷钼酸是合成乳酸丁酯较为理想的催化剂,在最佳条件下,催化合成乳酸丁酯酯化率在94%以上,且负载型催化剂回收容易,可重复使用。

The supported heteropoly acid catalysts were prepared by loading phosphotungstic acid or phosphomolybdic acid on the MCM-48 molecular sieve via the impregnation method,which were characterized by fourier transform infrared spectroseopy(FT-IR),N2 adsorption-desorption and X-ray diffraction(XRD).Butyl lactate was synthesized by using supported heteropoly acid as catalyst.The effects of reaction parameters such as n(n-butanol)∶n(lactate),the load amount of heteropoly acid and reaction time on esterification rate were discussed under the certain factors of reaction temperature and the amount of catalyst.Experiment results showed that the supported phosphotungstic acid or phosphomolybdic acid was a kind of suitable catalyst.Under the optimum reaction conditions,the esterification rate of butyl lactate was up to 94%.The supported catalyst could be recovered easily for recycling.