Fabrication of amino-functionalized Fe_3O_4@Cu_3(BTC)_2 for heterogeneous Knoevenagel condensation  

氨基化磁性Fe_3O_4@Cu_3(BTC)_2材料的合成及其在Knoevenagel缩合中的催化性能（英文）

作　　者：张艳梅 张静[2] 田苗苗[2] 储刚[2] 权春善 

机构地区：[1]大连民族大学生命科学学院,辽宁大连116600 [2]辽宁石油化工大学化学与材料科学学院,辽宁抚顺113001

出　　处：《Chinese Journal of Catalysis》2016年第3期420-427,共8页催化学报（英文）

基　　金：supported by the National Natural Science Foundation of China (21203017);the Open Fund of State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences(N-11-3);the Program for Liaoning Excellent Talents in University (LNET);the Fundamental Research Funds for the Central Universities (DC201502020304)~~

摘　　要：Metal organic frameworks（MOFs） are an important platform for heterogeneous catalysts.Although MOFs with a smaller particle size exhibit better catalytic performance because of less diffusion limitations,their separation and recycling after catalytic reactions are difficult.The integration of MOFs with magnetic nanoparticles could facilitate their recovery and separation.Especially,the shell thickness of the core-shell structured composites is controllable.In this study,amino-functionalized Fe3O4@Cu3（BTC）2 was fabricated by a stepwise assembly method and its catalytic performance in Knoevenagel condensation was investigated.The results demonstrated that the magnetic hybrid material exhibited a core-shell structure,with a shell thickness of about 2 00 nm.Furthermore,it not only exhibited high catalytic activity,but remarkably,it could also be easily recovered magnetically and recycled without obvious loss of catalytic efficiency after three cycles.金属有机骨架材料具有大比表面积、高孔隙率、热稳定性好、规整且可调控的孔结构、易于功能化的骨架金属离子和有机配体等优点,是制备多相催化剂的重要材料之一.虽然减小金属有机骨架材料等多孔材料的粒径可以提高反应物的传质效率,从而提高其催化活性;但是,纳米尺寸催化剂的分离和回收困难.将磁性纳米粒子和金属有机骨架材料结合制备具有核-壳结构的磁性金属有机骨架材料是解决上述问题的有效方法.此类材料兼具磁性材料和金属有机骨架材料的双重优势,既可以磁性分离,又具有金属有机骨架材料的催化活性.而且,厚度可控的壳层材料表现出与纳米催化剂相当甚至更好的催化活性.我们采用逐层自组装方法制备了核-壳结构的磁性Fe_3O_4@Cu_3(BTC)_2复合材料,并对材料进行氨基化修饰,制备了基于金属有机骨架材料的磁性多相碱催化剂.采用粉末X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、透射电镜(TEM)、扫描电镜(SEM)、氮气吸附等方法对材料的组成和结构进行了表征,并考察了材料在Knoevenagel缩合反应中的催化性能.首先采用粉末XRD表征材料的晶体结构.在复合材料Fe_3O_4@Cu_3(BTC)_2的XRD谱中,同时出现了Fe_3O_4和Cu_3(BTC)_2的特征衍射峰.采用氨基配体修饰后,材料的XRD谱没有明显变化,说明修饰后的材料保持了Fe_3O_4@Cu_3(BTC)_2的晶体结构.透射电镜结果表明,包裹25次得到的磁性复合材料Fe_3O_4@Cu_3(BTC)_2是以Fe_3O_4为核心,以Cu_3(BTC)_2为壳的核-壳结构,壳层厚度大约为200 nm.氨基修饰后,材料的透射电镜图相对修饰前无明显变化.扫描电镜结果表明,合成的Fe_3O_4为球形结构,粒径为100–600 nm.采用Cu_3(BTC)_2进行包裹后,在Fe_3O_4表面生长了由Cu_3(BTC)_2纳米颗粒组成的壳层.采用氨基配体修饰后,材料的形貌无明显改变.进一步采用氮气吸附表征材料的孔结构并测定材料�

关 键 词：FE3O4 Metal organic frameworks Heterogeneous catalyst Knoevenagel condensation Magnetic separation 

分 类 号：O643.36[理学—物理化学]