吡啶羧酸杂合配体MOFs材料的组装及吸附性能研究

发布时间：2018-07-25 19:50

【摘要】：金属有机骨架化合物(Metal-Organic Frameworks,简称:MOFs),以其高的比表面积、丰富多样的结构以及可功能化修饰的孔道受到了人们的广泛关注。通过合理地设计有机配体并采用适当的金属源可以制备具有预期结构的MOFs材料并实现其结构的功能化。MOFs材料作为一种新型功能化多孔材料,在气体吸附与分离、质子传导、药物缓释、传感、催化以及光电磁等领域均展现出了潜在的应用价值。近年来,由于MOFs材料具有高比表面积以及低密度等特点,其在气体吸附与分离应用方面展示出了巨大的优势。通过在结构中引入开放的金属位点、路易斯碱活性位点或形成穿插结构可以显著提高MOFs材料的气体吸附与分离性能。这种结构和功能的可调控性使MOFs材料在二氧化碳捕捉、气体存储以及天然气纯化等方面具有重要的实际应用价值。因此,本论文主要围绕MOFs材料在气体吸附与分离方面的应用展开了一系列研究工作。本论文选用两个吡啶羧酸类有机物3,5-二(4’-羧基苯基)吡啶(H_2BCPPy)和2,6-二(3’,5’-二羧基苯基)吡啶(H_4BDCPPy)作为配体,利用次级结构基元法以及超分子构筑块法与不同种类的金属源构筑了11个结构新颖的MOFs材料,对所合成的化合物进行了结构解析、性质表征及性能测试,并深入探究了这一系列MOFs材料在气体吸附与分离、碘的吸附与释放及有机染料的吸附与分离等方面的应用。本论文的研究成果主要包含以下三个方面:(1)以吡啶二齿羧酸H_2BCPPy为有机配体,与含有不同阴离子的金属铜源通过自组装法制备了五个结构新颖的MOFs材料1-5。其中,化合物1和2均采用硝酸铜为金属源,通过改变反应溶剂的种类得到了两个结构新颖的化合物,两个化合物的结构中均具有经典的轮桨状双核铜无机次级结构基元。化合物3和4均是以碘化亚铜为金属源制备的MOFs材料。将碘离子引入到反应体系中,通过改变金属源与有机配体的比例得到了两个结构不同的化合物,其结构中均具有经典轮桨状双核铜以及多核Cu4I4金属簇两种无机次级结构基元。化合物3的比表面积大于其他已报道的基于Cu4I4金属簇的MOFs材料,而且它对一些小分子气体具有很好的吸附能力,并能高效分离氧气和氮气、丙烷和甲烷。化合物4所具有的超高孔隙率(78.2%)使其表现出优异的碘吸附与释放能力。化合物5是以硫酸铜为金属源制备的MOFs材料。将硫酸根离子引入反应体系中,得到了同时具有经典轮桨状双核铜以及少见的六核硫酸铜簇两种无机次级结构基元的结构。化合物5的阴离子骨架结构及空旷的孔体积使其能够快速吸附阳离子有机小分子染料(亚甲基蓝、甲基紫、罗丹明B)以及中性染料(中性红),但是不吸附阴离子染料(甲基橙和金橙II)。此外,化合物5能够快速从等摩尔混合染料甲基橙亚甲基蓝和金橙II亚甲基蓝中选择性吸附阳离子染料亚甲基蓝。(2)以吡啶二齿羧酸H_2BCPPy为有机配体,与不同的金属源构筑了四个具有高稳定性的MOFs材料6-9。其中化合物6和7为同构的化合物。化合物6的结构中包含较少报道的九连接三核金属铟簇无机次级结构基元,因此,化合物6不仅具有较好的热稳定性能,而且能够在水蒸气中较为稳定地存在。化合物6对二氧化碳展现出很好的捕获能力,在常压273和195 K条件下对二氧化碳的最大吸附量为129和400 cm3 g-1。此外,化合物6对氧气和氮气、二氧化碳、乙烷、丙烷和甲烷有很好的分离能力。通过改变合成化合物7时反应溶剂的种类,得到了另一种具有无限金属锰链的二维层状的化合物8,在该化合物的结构中,有机配体表现出较强的天线效应,对金属锰的荧光有明显的增强效果。化合物9是以硝酸镉为金属源构筑的具有无限金属镉链的MOFs材料,其结构中独特的3.5?超微孔孔道使其对二氧化碳和氮气具有很好的筛分效应。(3)以吡啶四齿羧酸H_4BDCPPy为有机配体,利用超分子构筑块法与两种金属源制备了两个具有不同金属有机多面体笼的MOFs材料10-11。这两种化合物的结构中都具有较少报道的线型四核金属簇。其中化合物10具有较高的比表面积,且对一些小分子气体具有很好的吸附能力,并能高效地分离丙烷和甲烷。化合物11结构中具有少见的48高连接数金属有机多面体笼。本论文中,利用次级结构基元法及超分子构筑块法,采用两种吡啶羧酸类配体与不同的金属源构筑了11个结构新颖的MOFs材料。利用MOFs材料结构中的多孔性,通过分析不同材料各自的结构特点,将实验与理论模拟相结合,探究了这些材料在小分子气体的吸附与分离、碘吸附与释放以及有机染料的吸附与分离方面的应用前景。
[Abstract]:Metal-Organic Frameworks (MOFs) has attracted wide attention for its high specific surface area, rich diversity of structures and functional modified pores. By rational design of organic ligands and appropriate metal sources, the expected structure of MOFs materials can be prepared and their structure can be realized. Functional.MOFs material, as a new functional porous material, has shown potential application value in the fields of gas adsorption and separation, proton conduction, drug release, sensing, catalysis and photoelectricity. In recent years, because of the high specific surface area and low density of MOFs, it has been used in the application of gas adsorption and separation. By introducing open metal sites in the structure, the Lewis base active site or interspersed structure can significantly improve the gas adsorption and separation performance of the MOFs material. This structure and function can make MOFs materials in carbon dioxide capture, gas storage, and natural gas purification. Therefore, this thesis focuses on the application of MOFs materials in the application of gas adsorption and separation. This paper uses two pyridine carboxylic acids, 3,5- two (4 '- carboxy phenyl) pyridine (H_2BCPPy) and 2,6- two (3', 5 '- two carboxy phenyl) pyridine (H_4BDCPPy) as a ligand. 11 novel MOFs materials were constructed by the hierarchical element method, supramolecular block method and different kinds of metal sources. The structural analysis, characterization and performance testing of the synthesized compounds were carried out. The adsorption and separation of gas, adsorption and release of iodine and adsorption of organic dyes on this series of MOFs materials were deeply explored. The research results of this paper mainly include the following three aspects: (1) five novel structural MOFs materials, 1-5., are prepared by self assembly by using H_2BCPPy as the organic ligand with pyridine two tooth carboxylic acid as the organic ligand, and the compounds 1 and 2 use copper nitrate as the metal source by changing the reaction. Two novel compounds were obtained, and the structure of the two compounds had the classical round paddle double nuclear copper inorganic secondary structural elements. The compounds 3 and 4 were MOFs materials prepared with copper iodide as the metal source. The iodide ion was introduced into the reaction system, and the ratio of the metal and organic ligands was changed. Two compounds with different structures are composed of two kinds of inorganic secondary structure elements, classical wheel propeller double nucleus copper and multi nucleus Cu4I4 metal cluster. The specific surface area of compound 3 is larger than that of other reported MOFs materials based on Cu4I4 metal clusters, and it has good adsorption capacity for some small molecule gas bodies and can be separated efficiently. Oxygen and nitrogen, propane and methane. The super high porosity (78.2%) of compound 4 shows excellent iodine adsorption and release ability. Compound 5 is a MOFs material prepared with copper sulfate as the metal source. The sulfate ion is introduced into the reaction system, and it has a canonical paddle double nucleated copper and a rare six nuclear copper sulfate. The structure of two inorganic secondary structural elements. Compound 5's anionic skeleton structure and open pore volume enable it to quickly adsorb cationic organic small molecular dyes (Ya Jiaji blue, methyl violet, Luo Danming B) and neutral dyes (neutral red), but no anion dye (methyl orange and gold orange II). In addition, compound 5 can be fast. The selective adsorption of cationic dye methylene blue from methyl orange methylene blue and gold orange II methylene blue. (2) with pyridine two tooth carboxylic acid H_2BCPPy as organic ligand, four compounds with high stability, 6-9., compound 6 and 7, are constructed with different metal sources. Compound 6 structure Containing less reported nine connection three nuclear metal indium inorganic secondary structural elements, therefore, compound 6 not only has good thermal stability, but also can be more stable in water vapor. Compound 6 shows a good capture capacity for carbon dioxide, and the maximum adsorption capacity of carbon dioxide to carbon dioxide under the condition of 273 and 195 K is 12. 9 and 400 cm3 g-1. in addition, compound 6 has a good separation capacity for oxygen and nitrogen, carbon dioxide, ethane, propane, and methane. By changing the kind of reaction solvent of synthetic compound 7, another two-dimensional layered compound with infinite metal manganese chain is obtained. In the structure of the compound, the organic ligand shows a strong day. Line effect has an obvious enhancement effect on the fluorescence of metal manganese. Compound 9 is a MOFs material with infinite metal cadmium chain constructed with cadmium nitrate as the metal source. The unique 3.5? Ultra micropore channel in its structure makes it have a good screening effect on carbon dioxide and nitrogen. (3) using the pyridine four tooth carboxylic acid as the organic ligand, using superfractionation. Two MOFs materials with different metal organic polyhedron cages with different metal organic polyhedron cages have been prepared by substructure block method and two kinds of metal sources. The structure of the two compounds with different metal organic polyhedron cages have less reported linear four core metal clusters, of which compound 10 has a high specific surface area, and has a good adsorption capacity for some small molecular gases and can be efficiently separated. A rare 48 high junction metal polyhedron cage is rare in the 11 structure of propane and methane. In this paper, 11 novel MOFs materials have been constructed with two kinds of pyridine carboxylic ligands and different metal sources using the secondary structure element method and supramolecular block method. The structure characteristics of different materials are analyzed, and the experimental and theoretical simulation are combined to explore the application prospects of these materials in the adsorption and separation of small molecular gases, the adsorption and release of iodine, and the adsorption and separation of organic dyes.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O641.4;O647.3

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