摘要
以ZnBr2和四乙基溴化铵(Et4NBr)为原料,通过溶剂热法配位制备了锌配合物催化剂,研究了反应溶剂、加料方式、原料摩尔比、反应时间和反应温度对锌配合物制备收率的影响。较优的制备工艺条件为:乙醇为溶剂、采用反滴加料、n(Zn)∶n(N)=1∶2、制备温度为50℃、反应时间为0.5 h,锌配合物的收率达92.30%。采用X线衍射(XRD)、傅里叶红外光谱(FT-IR)、元素分析(EA)和发射光谱仪(ICP-AES)对锌配合物进行表征。结果表明:不同原料摩尔比制备的锌配合物是不同于原料的新物质,推断出锌配合物的化学式为(Et4N)2ZnBr4。另外,初步探索了锌配合物对环氧乙烷酯化反应的催化性能。结果表明:锌配合物催化剂具有优良的活性,环氧乙烷转化率达95.6%,副产二乙二醇(DEG)选择性不大于1.72%,循环使用5次后催化剂活性无明显下降。
A zinc coordination compound was prepared from tetraethylammonium bromide(Et4NBr) with zinc bromide in ethanol solution.The effects on the yield of coordination compound were investigated.The yield of zinc coordination compound of 92.3%was obtained under the following optimal conditions:ethanol as solvent,anti-drop for feeding,n(Zn)∶n(N) molar ratio of 1∶2,reaction time of 0.5 h,temperature of 50 ℃.The zinc coordination compound was characterized with X-ray diffraction(XRD),fourier transform infrared spectroscopy(FT-IR),elemental analysis(EA) and emission spectrometry(ICP-AES).It was indicated that the obtained compound was a new one with the concluded molecular formula of(Et4N)2ZnBr4.The catalytic performances by the zinc coordination compound for esterification of ethylene oxide(EO) were investigated.Results showed that zinc coordination compound had better activity,the conversion of EO could reach 95.6%,while selectivity of dithylene glycol was less than 1.72%.Catalytic activity was not decreased obviously after recycling five times.
出处
《南京工业大学学报(自然科学版)》
CAS
北大核心
2012年第5期122-127,共6页
Journal of Nanjing Tech University(Natural Science Edition)
基金
中国石化集团公司基金资助项目(408077)
江苏省精细石油化工重点实验室开放课题(KF0901)
关键词
锌配合物
环氧乙烷
酯化
催化性能
zinc coordination compounds
ethylene oxide
esterification
catalytic performance