聚离子液体固体酸催化剂的制备及催化甘油乙酰化性能  

Synthesis of poly(ionic liquid)s solid acid catalyst and its catalytic performance in glycerol acetylation

作　　者：张吕鸿[1] 王瑞瑾[1] 姜斌[1] 孙永利[1] 杨华伟[1] ZHANG Lühong;WANG Ruijin;JIANG Bin;SUN Yongli;YANG Huawei(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学化工学院,天津300072

出　　处：《化工进展》2017年第7期2497-2503,共7页Chemical Industry and Engineering Progress

摘　　要：通过自由基共聚,质子化及离子交换两步法合成聚咪唑基离子液体固体酸催化剂(PILs)。采用傅里叶红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)、X射线光电子能谱分析(XPS)、热重分析(TGA)、元素分析和电位滴定的方法对该催化剂的结构和性能进行了表征。结果表明该催化剂具有层状结构、良好的热稳定性和较高的质子酸浓度,并在不加入带水剂的条件下,考察了该聚离子液体固体酸催化剂对甘油乙酰化反应的催化作用。结果表明该PILs固体酸催化剂具有良好的选择催化活性,在酸醇摩尔比为6∶1、催化剂用量4%(质量分数)、120℃、4h的最优条件下,甘油转化率达98.2%,单乙酸甘油酯的选择性为11.6%,二乙酸甘油酯和三乙酸甘油酯的总选择性高达88.4%,优于Amberlyst-15的催化效果。该催化剂易回收,具有良好的水热稳定性,且重复使用4次经再生后仍能保持良好的选择催化活性。A functional poly(ionic liquid)s(PILs)solid acid catalyst was prepared through free radicalcopolymerization of ionic liquids precursor and the subsequent protonation and ion-exchange withconcentrated sulfuric acid.The as-prepared acidic catalyst was characterized by FTIR,SEM,TEM,XPS,TGA,elemental analysis and potentiometric titration.It was found that the acid PILs had amulti-layer microstructure with favorable thermal stability and high Br?nsted acid site density.Itsperformance was evaluated in the acetylation of glycerol without any water-carrying agent.It exhibitedhigh catalytic activity and selectivity.Glycerol conversion of98.2%,monoacetin selectivity of11.6%and total diacetin and triacetin selectivity of88.4%were obtained under the optimum reactionconditions of n(acetic acid)∶n(glycerol)=6,catalyst dosage=4%of glycerol,120℃,4h.The catalyticperformance was better than that using Amberlyst-15.The PILs solid acid catalyst was easily recoveredand had good hydrothermal stability.A further exchanging of used PILs with H2SO4could make thecatalyst restore its catalytic performance and it could be reused for4times.

关 键 词：催化剂 聚合 离子液体 选择性 甘油 乙酰化 

分 类 号：TQ032.4[化学工程]