高效净化氯代气体功能化金属有机骨架材料的分子调控制备

发布时间：2018-01-05 14:28

本文关键词：高效净化氯代气体功能化金属有机骨架材料的分子调控制备　出处：《北京交通大学》2017年博士论文　论文类型：学位论文

【摘要】：随着聚氯乙烯工业和氯甲烷工业的快速发展,氯代挥发性有机化合物(Chlorinated volatile organic compounds,Cl-VOCs)对环境造成巨大的破坏,危害人类健康,其监测和治理迫在眉睫。目前常用的治理方法有:吸附法,热焚烧法,生物处理法,光催化氧化法和电化学法等。吸附法由于设备简单,吸附剂可循环使用等优点成为首选,其关键是选择合适的吸附剂。常用的吸附剂主要有活性炭,沸石分子筛,硅胶和活性氧化铝等。与这些传统的吸附剂相比,一种新型的多孔材料即金属有机骨架材料(Metal-organic frameworks,MOFs)或者多孔配位聚合物(Porous coordination polymer,PCPs)受到了广泛的关注。MOFs是由无机次级结构单元(inorganic secondary building units,SBUs)和桥联的有机配体组成的,由于其具有很高的比表面积,大的孔容和均一可调的孔径所以被广泛的应用于气体吸附和分离,催化剂和化学传感器等研究领域,但对于氯代气体的吸附和分离的研究尚未开始。MOFs材料具有其得天独厚的优势:孔道的大小、比表面积、活性位点和刚柔性都是可以通过合理地选择金属离子和有机配体来进行分子调控。因此,如何利用分子调控的手段来制备MOFs材料,从而实现对氯代气体的高容量,高选择性的吸附和分离也就成了科学家们研究的热点。本论文的主要内容和创新点如下:1.根据分子筛效应针对要吸附和分离的目标气体选择孔径合适的MOFs材料,系统全面的从材料的制备、表征和孔结构性质等方面进行研究,再具体研究目标气体的吸附和分离过程,主要包括热力学、动力学和吸附机理等方面。在本论文的第三章中,我们制备了一种典型的铜基金属有机骨架材料HKUST-1,详细研究了二氯甲烷和三氯甲烷这两种Cl-VOCs在其上的吸附和分离过程。此外,还通过理想溶液吸附理论(ideal solution adsorbed theory,IAST)来预测得到二氯甲烷和三氯甲烷双组份混合气体的吸附选择性和扩散选择性,在318 K和2.8 kPa的条件下吸附选择性为3.04,扩散选择性为8.93。在上述研究的基础上,深入探讨了 HKUST-1对二氯甲烷和三氯甲烷吸附和分离过程的机理。2.对金属有机骨架中的有机配体进行功能化修饰,进而增强其对氯代气体的吸附容量和吸附选择性,从而达到分离的目标。在本论文的第四章中,我们制备了两种典型的MOFs材料,即MOF-5和与其结构类似的带有氨基的IRMOF-3,然后系统的研究了其对二氯甲烷和三氯甲烷的吸附和分离过程。结果表明,尽管IRMOF-3由于氨基的存在使孔径和孔容变小,但与MOF-5相比,其对二氯甲烷和三氯甲烷的吸附容量分别提高了 24.5%和27.4%。进一步通过IAST计算得到二氯甲烷和三氯甲烷双组份混合气体在IRMOF-3的吸附选择性和扩散选择性为5.62和3.88,高于MOF-5。吸附容量、吸附选择性和扩散选择性的增加都是由于IRMOF-3上的氨基与氯代气体相互作用增强导致的结果。3.从无机化学的角度出发,可以对作为框架节点的金属团簇做设计来实现对MOFs材料结构和性能的进一步调控,特别是在金属团簇上引入金属空配位来增强其气体吸附能力。在本论文的第五章中,我们在经典的锌基金属有机骨架材料MOF-5中成功的掺杂铜元素,在溶剂热晶化过程中,铜元素可以成功的取代金属团簇上的锌元素从而形成双金属的MOFs材料。然后系统的研究了铜掺杂浓度对晶体结构和气体吸附性质的影响,对所有脱除溶剂后的样品的BET比表面积测试表明在铜掺杂浓度≤0.125时,MOF-5的BET比表面积随着铜掺杂量的升高而减小,但当铜掺杂浓度0.125时,BET比表面积随着掺铜含量的增加而增大,当掺铜浓度达到1.0时,比表面积值达到最大。这项工作率先实现了在金属有机骨架MOF-5材料的金属节点上掺杂不同量的铜元素取代原有锌元素,并系统的研究了金属元素取代量的不同对晶体结构和吸附性质的影响。4.在第四章和第五章分别研究了有机配体的功能化修饰和金属团簇的金属元素取代后,决定对MOFs材料的复合材料进行探索,进而研发针对氯代气体的荧光传感器。在本论文的第六章中,我们成功的通过两步溶剂热法制备了一种新颖的ZnO纳米颗粒与金属有机骨架材料MOF-5的复合材料。ZnO纳米颗粒的包覆有效的增强了 MOF-5的水稳定性,从而使得ZnO/MOF-5具有耐潮解的特性,大大的拓宽了其应用范围。此外,通过测试这种复合材料的光致发光性质,发现其光致发光光谱的峰位置在460 nm和550 nm处。目前此项工作只研究了前期,为实验室后期氯代气体的荧光传感器的研究和探索奠定了基础。
[Abstract]:With the rapid development of PVC industry and chloromethane industrial, chlorinated volatile organic compounds (Chlorinated volatile, organic compounds, Cl-VOCs) caused great damage to the environment, endanger human health, the imminent monitoring and governance. The commonly used treatment methods are: adsorption, thermal incineration method, biological treatment method, photocatalytic oxidation adsorption method and electrochemical method. Because the equipment is simple, adsorbent recycling and other advantages to become the first choice, the key is to select suitable adsorbents. Adsorption are mainly used activated carbon, zeolite molecular sieve, silica gel and activated alumina. Compared with the traditional adsorbent, a novel porous material the metal organic framework material (Metal-organic frameworks, MOFs) or porous coordination polymer (Porous coordination, polymer, PCPs) have been widely concerned.MOFs is composed of inorganic secondary structure Unit (inorganic secondary building units, SBUs) bridging organic ligands and composition, because of its high surface area, large aperture Kong Rong and adjustable uniform it is widely used in gas adsorption and separation, catalyst and chemical sensors and other fields, but the study of adsorption and separation for chloride the gas has not yet started its advantages of.MOFs material has richly endowed by nature: pore size, surface area, active site and the rigidity is through the reasonable selection of metal ions and organic ligands to molecular regulation. Therefore, how to use the molecular regulation means of preparing MOFs materials, in order to achieve high capacity of chloride gas adsorption and separation, high selectivity has become a hotspot for scientists to study. The main contents and innovations of this paper are as follows: 1. according to the molecular sieve effect for adsorption and separation. Select the appropriate material gas MOFs aperture, systematically from the material preparation, characterization and study of pore structure properties, and adsorption and separation process of the specific research target gas, mainly including thermodynamics, kinetics and adsorption mechanism. In the third chapter of this thesis, we prepared a kind of typical copper based metal organic frameworks prepared HKUST-1, a detailed study of the adsorption and separation process of dichloromethane and trichloromethane these two kinds of Cl-VOCs in it. In addition, the ideal adsorption solution theory (ideal solution adsorbed theory, IAST) to predict dichloromethane and trichloromethane two-component mixed gas selective adsorption and diffusion in selectivity. 318 K and 2.8 kPa under the conditions of adsorption selectivity was 3.04, diffusion selectivity based 8.93. in the above research, in-depth study of the HKUST-1 of dichloromethane and three methyl chloride The mechanism of.2. adsorption and separation process of alkane functionalization of organic ligand metal organic frameworks, and then enhance the chlorine gas adsorption capacity and adsorption selectivity, in order to achieve the separation of the target. In the fourth chapter of this thesis, we prepared two kinds of typical MOFs materials were prepared, which is similar to MOF-5 and with the structure of amino IRMOF-3, and then studied the dichloromethane and trichloromethane adsorption and separation process. The results show that although the IRMOF-3 due to the presence of amino group so that the pore size and pore volume decreased, but compared with MOF-5, the adsorption capacity of methylene chloride and chloroform respectively increased 24.5% and 27.4%. further calculated by IAST get the dichloromethane and trichloromethane two-component mixed gases in selective adsorption and diffusion selectivity of IRMOF-3 is 5.62 and 3.88 higher than that of MOF-5., the adsorption capacity, adsorption selectivity and expansion The increase is due to the selective dispersion of amino and chlorine on IRMOF-3 gas generation and enhanced the interaction result of.3. from the perspective of inorganic chemistry, of metal clusters as a framework for cluster node do design to achieve further regulation on the structure and properties of MOFs materials, especially in the introduction of metal free with metal cluster enhancement the gas adsorption capacity. In the fifth chapter of this thesis, we succeed in Cu doped zinc based metal organic framework material MOF-5 in the classic, in the solvothermal crystallization process, copper can replace zinc metal clusters to form a double metal MOFs material and then the system successfully. Study on the effects of copper doping on crystal structure and adsorption properties of gases, for all the samples after removing the solvent BET specific surface area test results show that the copper doping concentration is less than or equal to 0.125, MOF-5 BET surface Volume decreases with the increase of Cu doping amount, but when the copper doping concentration of 0.125 BET, the specific surface area increases with the increase of Cu doped content, when the content of copper concentration reached 1, the maximum surface area value. This work was first realized in copper metal joint metal organic framework materials on the MOF-5 doped with different amounts of zinc to replace the original elements, and system of the metal element substituted elements of different effects on crystal structure and adsorption properties of.4. in the fourth and fifth chapters discuss the functionalization of organic ligands and metal clusters from generation, decided to carry out exploration of MOFs composite materials then, according to the research of fluorescence sensor chlorine gas. In the sixth chapter of this thesis, we successfully combined a novel ZnO nano particles and metal organic framework materials of MOF-5 prepared by solvothermal method step two The coating material of.ZnO nanoparticles can effectively improve the water stability of MOF-5, so that ZnO/MOF-5 has the characteristics of resistance to ChaoXie, greatly broadened the scope of its application. In addition, the luminescence properties of the composites induced by testing light, found that the photoluminescence peak position at 460 nm and 550 nm at present. This work only on the stage, which laid the foundation for the research and exploration of fluorescent sensor laboratory late chlorinated gas.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O647.33

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