自制Ti/W-MCM-41介孔分子筛催化制备乳酸戊酯

采用自制的介孔分子筛Ti/W-MCM-41催化乳酸与正戊醇的酯化反应,合成了乳酸正戊酯;利用红外光谱仪分析了催化剂的化学特征,考察了分子筛的WO3质量分数、催化剂用量、醇酸物质的量比、反应时间、催化剂重复使用性能等因素对目标产物酯化率的影响.结果表明,在nSi∶nTi=30∶1,WO3质量分数10%,550℃下焙烧6h条件下制得的催化剂具有良好的催化性能;其催化合成乳酸正戊酯适宜的反应条件为:0.2mol乳酸,催化剂用量0.5g,n(正戊醇)∶n(乳酸)=1.6∶1,反应时间100min,酯化率可达94.4%.该催化剂使用7次酯化率仍可达86.6%.

Preparation of namyl lactate catalyzed by titanium-based tungsten-containing MCM-41 mesoporous molecular sieve

A novel catalyst, Ti-based W-containing MCM-41 （Ti/W-MCM-41） mesoporous mo- lecular sieve was prepared. The mesoporous molecular sieve was employed to catalyze the esterification reaction of lactic acid and n-pentanol yielding namyl lactate. The effects of various parameters such as mass ratio of WO3, catalyst dosage, molar ratio of alcohol to acid, reaction time and reusability of the catalyst on the esterification rate were investigated. Results indicate that the mesoporous molecular sieve obtained at a n_Si：n_Ti= 30 ： 1, WO3 mass ratio of 10% after calcination at 550℃ for 6 h possesses good catalytic performance. Relevant molecular sieve catalyst can be well used to catalyze the esterification reaction of lactic acid and n-pentanol yielding namyl lactate under the optimized reaction condition of lactic acid 0.2 mol, alcohol to acid molar ratio of 1.6 ： 1, mass of catalyst 0.5 g, and reaction time of 100 mini resultant esterification rate is as much as 94.4%. Besides, the esterification rate is still over 86.6%after the catalyst is reused for 7 times.