类沸石咪唑酯骨架材料-8的形貌调控及其催化制氢性能  

Morphology Control and Catalytic Dehydrogenation Performance of Zeolitic Imidazolate Frameworks-8

作　　者：李旺 LI Wang(Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,太原030024

出　　处：《应用化学》2022年第7期1065-1072,共8页Chinese Journal of Applied Chemistry

基　　金：山西省优秀来晋博士科研资助项目(No.20202003);山西省高等学校科技创新项目(No.20201023);山西省高校大学生创新创业项目(No.2020348);校博士启动基金项目(No.20192025)资助。

摘　　要：类沸石咪唑酯骨架材料-8(ZIF-8)是一种具有较大比表面积和较强稳定性的多孔材料,被广泛应用在气体存储分离、催化等领域。该工作报道了不同实验条件如Zn^(2+)/2-甲基咪唑的物质的量比、表面活性剂用量和不同的反应溶剂对ZIF-8形貌和尺寸的影响,其中Zn^(2+)/2-甲基咪唑配比是影响形貌及尺寸的关键因素。通过扫描电子显微镜(SEM)、BET、和X射线衍射(XRD)对合成制备的ZIF-8纳米粒子进行表征,发现调变投料比可将样品粒径从1500 nm逐渐减小至850~250 nm,形貌由截角立方体转变为截角十二面体,最终变为十二面体。其中粒径为250 nm的ZIF-8纳米粒子比表面积为1730 m^(2)/g,孔径和孔容分别为1.5 nm和0.6 cm^(3)/g,由此可知该粒径ZIF-8具备非常优异的载体特性,故进一步采用浸渍法,以硼氨为还原剂,在该尺寸ZIF-8纳米粒子上原位负载贵金属/金属纳米粒子,并对其进行组分优化。所设计合成的催化剂ZIF-8/Pt_(0.002)@Ni_(0.2)在催化氨硼烷制氢实验中表现出卓越的性能,60 s即可催化氨硼烷完全放氢。Zeolitic imidazolate frameworks⁃8(ZIF⁃8)is a kind of porous material with large specific surface area and strong stability,which is widely used in gas storage,separation,catalysis and other fields.In this work,the effect of different reaction conditions,such as the molar ratio of Zn^(2+)to 2⁃methylimidazole,the amount of surfactant and the reaction solvents,on the size and morphology of ZIF⁃8 were reported.Among these conditions,the molar ratio of Zn^(2+)to 2⁃methylimidazole is the key factor affecting the size and morphology of ZIF⁃8.The synthesized ZIF⁃8 nanoparticles were characterized by SEM,BET and XRD.The size of ZIF⁃8 decreases gradually from 1500 nm to 850 nm then to 250 nm,and the morphology changes from truncated hexahedron to truncated dodecahedron and finally to dodecahedron.The specific surface area of ZIF⁃8 nanoparticles with a particle size of 250 nm is 1730 m^(2)/g,and the pore size and pore volume are 1.5 nm and 0.6 cm^(3)/g,respectively.Therefore,it can be seen that ZIF⁃8 nanoparticles with a particle size of 250 nm have excellent carrier characteristics.The impregnation method was further adopted to synthesize the supported catalyst,and boron ammonia was used as the reducing agent.The ZIF⁃8(250 nm)nanoparticles were loaded with metals/precious metal nanoparticles in situ,the component optimization and catalytic performance were further studied.The obtained catalyst ZIF⁃8/Pt_(0.002)@Ni_(0.2) shows excellent performance in hydrogen generation from aminoborane.

关 键 词：类沸石咪唑酯骨架材料-8 多孔材料 催化 

分 类 号：O643.3[理学—物理化学]