摘要
采用两步法制备了功能化双咪唑核离子液体-杂多酸盐催化剂,并用FT-IR对催化剂的结构进行了表征,考察了其在正十二醇与磷酸(质量分数85%)直接酯化高选择性地合成单十二烷基磷酸酯反应中的催化性能。结果表明,所合成的催化剂中杂多酸的Keggin结构均得到了较好的保持。杂多酸-离子液体复合催化剂的催化性能优于传统的纯杂多酸催化剂,其中在双-(3-甲基-1-咪唑)亚丁基磷钨酸盐催化剂质量分数0.67%、反应温度90℃和反应时间1 h的条件下,单酯收率和选择性分别达到了43.5%和99.9%;加入甲苯携水剂后,在最佳催化剂用量0.8%(质量分数)和120℃下反应24 h,单酯收率为93.5%,选择性为99.8%;重复使用6次后,该催化剂的活性基本保持不变,表明该功能性双核杂多酸离子液体是一种有潜力的新型酯化有机-无机复合催化材料。
A series of ionic liquid-heteropoly acid hybrid catalysts with bi-imidazolium cation were prepared via a two-step method.The structures of catalysts were characterized by FT-IR.The catalytic performances of direct esterification of phosphoric acid with lauryl alcohol to mono-dodecyl phosphate with high selectivity were studied.The results indicated that the hybrid catalysts had the same Keggin type structure as that of heteropoly acid.The catalytic activity of hybrid catalyst was higher than that of the pure heteropoly acid catalyst.With 0.67%（mass fraction） catalyst dosage,the bis-（3-methyl-1-imidazolium） butylene phosphotungstate catalyst possessed the best catalytic performance with 43.5% yield and 99.9% selectivity of mono-dodecyl phosphate under 90℃ for 1 h reaction among the hybrid catalysts.With toluene as dehydrant,a high yield of 93.5% with a very high selectivity of 99.8% for mono-dodecyl phosphate was achieved when the direct esterification of phosphoric acid with lauryl alcohol was carried out at 120℃ for 24 h under the optimum catalyst dosage of 0.8%（mass fraction）.The excellent activity and perfect reusability during a six-recycle test demonstrated that the bi-imidazolium cation ionic liquid-heteropoly acid was a very potential organic-inorganic hybrid catalyst.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2011年第3期482-487,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家重点基础研究发展计划项目(2009CB724701)资助
关键词
双核离子液体
杂多酸
酯化反应
单十二烷基磷酸酯
dicationic ionic liquids
heteropoly acid
esterification
mono-dodecyl phosphate
