乙醇中镧盐催化果糖脱水制备5-羟甲基糠醛的研究

摘要

A preliminary study of catalytic dehydration of fructose to 5-hydroxymethylfurfural (5-HMF) was carried out by using ethanol as solvent and lanthanum salt as catalyst. A comparison study indicated that the yields of 5-HMF in ethanol was much larger than those in water. LaCl3 had higher catalytic activity than La(NO3)3. Increasing the catalyst concentration can accelerate the reaction of dehydration of fructose to 5-HMF, but had little effect on increasing the maximum yield of 5-HMF. The yield of 5-HMF,as well as the reaction rate of dehydration of fructose to 5-HMF,increased along with the increase in temperature. The yield of 5-HMF up to 41.6 ％ was achieved after 20 min at 140℃.%以乙醇为反应溶剂,镧盐为催化剂催化果糖制备5-羟甲基糠醛(5-HMF)进行了初步研究.乙醇作为反应溶剂时,5-HMF产率远高于以水作为反应溶剂.氯化镧与硝酸镧相比具有更好的催化活性.提高催化剂浓度可以增大果糖转化为5-HMF的速率,但是对5-HMF的最大产率影响较小.随着反应温度的提高,果糖转化为5-HMF的速率增大,5-HMF的产率也明显提高.当反应温度为140℃时,反应20 min产率即可达到41.6%.