金属有机框架材料的设计合成、结构及质子导电性质研究

发布时间：2018-01-05 19:38

本文关键词：金属有机框架材料的设计合成、结构及质子导电性质研究　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：金属有机框架(Metal-Organic Frameworks,简称MOFs),也称之为多孔配位聚合物(Porous Coordination Polymers,简称PCPs),是由金属离子/簇(亦称次级构筑单元,Secondly Building Units,SBUs)和有机配体构筑而成。该材料凭借着结构可设计、孔道尺寸可调节、孔壁可功能化修饰以及高度晶态化等特点,在吸附/分离、导电、磁性、催化、荧光、铁电和生物医药等方面有着很好的应用前景。从MOFs材料被发现可以作为质子传输材料以来,科学家们开启了对MOFs材料质子导体性能的研究热潮,近几年来这一领域得到了飞速发展,使此应用迅速走向成熟。质子交换膜燃料电池中最为核心的部件就是质子交换膜,它能够隔开电池中的燃料和氧化剂,而且又允许质子在膜中自由通过,是影响电池寿命和性能的关键所在。化学家们通过改变配体种类、反应条件等构筑出了大量的具有优良导电性能的MOFs材料,并通过各种修饰方法来改善其导电性能,使这种应用更加趋于成熟,为实际应用打下了坚实的理论基础。在本文中,我们主要开展了以下主要工作:一、我们以MIL-88B结构为基础,选择含有不同官能团的有机配体与铬离子构筑成同构的Cr-MIL-88B结构,研究不同配体对质子导电性能的影响与改善。另外,通过配体掺杂的策略探究了该结构的无水导电特性。我们选择对苯二甲酸(H_2BDC)、2-氨基对苯二甲酸(H_2BDC-NH_2)、2-甲基对苯二甲酸(H_2BDC-CH3)、2,5-二甲基对苯二甲酸(H_2BDC-2CH3)等配体分别与金属铬盐合成不同配体的同构MIL-88B结构,并且选用辅助配体tpt装进晶体结构中将其柔性结构撑开,最后分别研究了Cr-MIL-88B、Cr-MIL-88B-NH_2、Cr-MIL-88B-tpt这三种配合物在不同湿度下的质子导电性能。另外,探究了利用不同配体合成的四种配体掺杂与Cr-MIL-88B同构的配合物,并初步测试了其无水质子导电性。通过测试发现Cr-MIL-88B结构的配合物具有较好的质子导电性质。二、设计合成了多羧酸配体L_1,5-苄巯基间苯二甲酸和柔性多羧酸配体L_2,1,2-二(2-磺酸基-4-羧酸苯基氧基)乙烷。基于多羧酸配体L_1与硝酸铜采用溶剂热法设计合成了两个异构的三维配合物1和配合物2。经过X-射线单晶衍射测试可知,配合物1的空间群是P-1,属于三斜晶系。该结构有两种铜簇,分别与配体相互连接构成一个沿a轴方向的一维孔道。配合物2的空间群是I4/m,属于四方晶系。配合物2是在配合物1的合成基础上通过添加三苯基膦的乙醇溶液而得到的。双核铜簇通过与配体相互连接构筑成两种交替排列的笼状结构。基于配体L_2,与硝酸铕和硝酸铽通过溶剂热法合成了两个同构的稀土三维配合物3。经过X-射线单晶衍射测试可知,配合物3的空间群是P-1,属于三斜晶系。配合物3和4的整个结构中沿a轴方向包含有两种不同的一维孔道,都是由六个配体和八个金属中心围绕而成,并且所有配体上的磺酸基全部分布于孔道中,具有很好的亲水性,但可能由于配体中掺杂的金属钠离子在配合物合成过程中参与了配位而导致整体骨架的水不稳定性,无法进行有水导电测试,由于配体上磺酸基团之间距离过大而无法在无水条件下构建质子通路,所以在无水条件下也不具备导电性能。后续工作中将探索并合成水稳定性较好的质子导体材料。
[Abstract]:Metal organic frameworks (Metal-Organic Frameworks, referred to as MOFs), also known as porous coordination polymer (Porous Coordination Polymers, referred to as PCPs), is made of metal ion / cluster (also known as the secondary building unit, Secondly Building Units, SBUs) and organic ligands. The material and structure can be designed with adjustable pore size. And the hole wall functionalization and highly crystalline characteristics in adsorption / separation, conductive, magnetic, catalytic, fluorescence, has a good application prospect of ferroelectric and biomedicine. Since MOFs materials are found can be used as proton transport materials, scientists have opened a research upsurge of proton conducting properties of MOFs the material, in recent years, this field has been the rapid development of the application of rapidly maturing. Most of the core components of proton exchange membrane fuel cell is the proton exchange membrane, it can separate the battery The fuel and oxidizer, and allow protons in the membrane by free, is the key to affect the battery life and performance. Chemists by changing the ligand type, reaction conditions such as a building with excellent electrical properties of MOFs materials, and to improve the conductivity of modified by various methods, make this application more mature, a solid theoretical foundation for the practical application. In this paper, we mainly carried out the following work: first, we based on the MIL-88B structure, forming the Cr-MIL-88B structure with different functional groups of organic ligands and chromium ions, of different ligands influence on the proton conductivity and improve. In addition, anhydrous conductive properties of the structure were explored by ligand doping strategy. We choose terephthalic acid (H_2BDC), 2- (H_2BDC-NH_2), 2- amino acid methyl Terephthalic acid (H_2BDC-CH3), 2,5- (H_2BDC-2CH3) two methyl terephthalate isomorphic MIL-88B structure respectively with the metal ligand chromate synthesis of different ligands, and the selection of auxiliary ligands TPT into the crystal structure of the flexible structure is opened, Cr-MIL-88B-NH_2 finally Cr-MIL-88B were analyzed, and proton conductivity of Cr-MIL-88B-tpt of these three complexes in different humidity conditions. In addition, to explore the complexes with different ligands of the four ligands with Cr-MIL-88B doping isomorphism, and preliminary test the anhydrous proton conductivity. It is found that the complex Cr-MIL-88B structure has good proton conductivity properties. Two, the design and synthesis of polycarboxylate ligands L_1,5- benzyl thiol isophthalic acid and two flexible multi carboxylate the two ligand L_2,1,2- (2- sulfo -4- carboxylic acid phenyl ethoxy) ethane. Design method by using solvothermal polycarboxylic acid ligands and copper mining based on L_1 Three dimensional complexes 1 and two heterogeneous complexes 2. through X- ray diffraction test shows the synthesis, with 1 of the space group is P-1, three belongs to triclinic. This structure has two kinds of copper clusters, respectively connected with ligand to form a 1D channels along the a axis. The complex space group the 2 is I4/m, belongs to tetragonal. Complex 2 by adding three ethanol solution of triphenylphosphine obtained in the synthesis of complexes 1. On the basis of binuclear copper clusters by connecting with each other to build into two kinds of ligands are arranged alternately. The cage structure based on ligand L_2, nitrate and europium and terbium nitrate by solvent hydrothermal synthesis of rare earth complexes with 3D isomorphism of two and 3. by X- ray diffraction shows that the complex space group is 3 P-1, three belongs to triclinic. Complexes 3 and 4 in the whole structure along the a axis contains two different 1D channels, is made up of six From around the eight ligands and metal centers, and all the sulfonic acid ligand part distributed in pores, have good hydrophilicity, but may be due to sodium metal ion ligand complexes doped in the synthesis process involved in the coordination and overall framework of water lead to instability, not the water conducting test, because between the ligand sulfonic acid groups on the distance is too large it is unable to construct the proton pathway under anhydrous conditions, so under anhydrous conditions do not have electrical properties. The follow-up work will explore and synthesis of water stable proton conductor material.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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