| 供稿: 刘彦;常玥;查飞 | 时间: 2019-01-04 | 次数: |
作者单位:西北师范大学化学化工学院;河南理工大学物理化学系
摘要:以酸活化坡缕石为载体,用回流蒸发吸附法制备了坡缕石负载的Keggin型磷钼杂多酸催化剂,并用红外光谱、X-射线粉末衍射、热重分析、扫描电镜对其进行了表征.将其应用于催化合成柠檬酸三丁酯以检验其催化性能,采用正交实验法和单因素法探讨了催化剂用量、酸醇摩尔比和反应时间等因素对反应的影响,找到了最佳反应条件并进行了催化剂稳定性测试.实验结果表明,酸化坡缕石负载磷钼酸催化合成柠檬酸三丁酯的优化反应条件为:n(柠檬酸)∶n(正丁醇)=1∶4,反应时间为2.5 h,反应温度为145℃,催化剂用量为1.5 g,柠檬酸用量为0.05 mol,在此条件下,最高酯化率可达85.1%.催化剂便于从反应体系分离,重复性实验表明催化剂可以多次回收使用.
基金:河南省基础与前沿技术研究计划项目(072300460050);河南省教育厅创新人才支持计划项目(2009HASTIT021);甘肃省高分子材料重点实验室资助项目(ZD-04-11);
DOI:10.16186/j.cnki.1673-9787.2009.03.004
分类号:TQ414.4
Abstract:The catalyst of molybdophosphoric acid supported on acid activated palygorskite was prepared via adsorption through reflux and evaporation.It was characterized by FTIR, XRD spectroscopy, SEM as well as thermogravimetry.Then, the synthesis of trioctyl citrate by citric acid together with n-butanol as reaction mass was used to test its activity.Several factors including the amount of catalyst, the ratio of acid to alcohol and reaction times were discussed by means of single factor and orthogonal experimental design, to get the optimal condition.The results show that the yield could reach 85.1% under the best condition: the amount of citric acid is 0.05 mol and the moral ratio of n (citric acid) ∶n (n-butanol) is 1 ∶4, reaction time is 2.5 h, mass of the catalyst is 1.5 g and reaction temperature is 145 ℃.The recycling tests show that the catalyst can be easily separated from the reaction systems and be reused for several times.