Zr-MOFs材料的合成及对乙酰丙酸吸附作用的研究

发布时间：2018-05-25 13:25

本文选题：Zr-MOFs材料 + 一元羧酸　；参考：《长春工业大学》2017年硕士论文

【摘要】：金属-有机骨架材料(MOFs)作为一种新兴的高度有序的结晶多孔材料,在过去的几十年里,已成为化学与材料科学学科研究的热点。因其具有永久性的孔隙率和较大的比表面积,以及结构表面多样的特异性官能团,使其在气体存储、吸附与分离、催化、药物缓释等方面表现出良好的应用前景。追求更高比表面积是MOFs材料研究的永恒目标。本实验中采用微波辅助法通过添加不同的一元羧酸作为合成稳定剂,来合成Zr-MOFs材料:UiO-66、UiO-67和UiO-66-NH2,希望能获得具有更高比表面积的Zr-MOFs材料,采用的一元羧酸有甲酸、乙酸、丙酸、丙烯酸、丁酸、异辛酸、苯甲酸。对合成出的Zr-MOFs进行了粉末X射线衍射分析、扫描电镜、N2物理吸附、热重等一系列表征,发现除甲酸外,加入其他一元羧酸均能合成出形貌较好的Zr-MOFs材料,但不同的一元羧酸对Zr-MOFs材料的结晶度、晶粒尺寸以及比表面积有影响。乙酰丙酸是一种十分具有应用价值的生物质平台分子,是合成各种轻化工产品的基本原料。对产物进行分离提纯是乙酰丙酸制备过程的重要问题。本实验中分别以UiO-66、UiO-67和UiO-66-NH2作为吸附剂用于吸附乙酰丙酸水溶液,发现UiO-66和UiO-66-NH2对乙酰丙酸有吸附作用。并以UiO-66为重点研究对象,对Ui O-66吸附乙酰丙酸的过程做了一系列研究,如UiO-66对乙酰丙酸的吸附速率,以及乙酰丙酸溶液的浓度以及温度等条件对UiO-66吸附乙酰丙酸能力的影响。实验发现,当乙酰丙酸水溶液浓度为70.0 mg/mL时,UiO-66对其饱和吸附量可达到291 mg/g。同时简单的模拟乙酰丙酸的工业生产环境,在乙酰丙酸水溶液中加入糠醇和甲酸,发现UiO-66对乙酰丙酸的选择性吸附较强,糠醇与甲酸的存在对UiO-66吸附乙酰丙酸的能力基本无影响。对吸附后的UiO-66晶体进行了脱附再生实验,发现经过5次脱附再生后,晶体骨架完好,对乙酰丙酸仍有较高的吸附能力,可重复性使用。
[Abstract]:As a new and highly ordered crystalline porous material, metal-organic skeleton material has become a hot topic in the field of chemistry and material science in the past few decades. Because of its permanent porosity, large specific surface area and various specific functional groups on the structural surface, it has a good application prospect in gas storage, adsorption and separation, catalysis, drug slow release and so on. The pursuit of higher specific surface area is the eternal goal of MOFs materials research. In this experiment, the microwave-assisted method was used to synthesize Zr-MOFs materials: UiO-66, UiO-67 and UiO-66-NH2 by adding different monocarboxylic acids as synthetic stabilizers, hoping to obtain Zr-MOFs materials with higher specific surface area. The monocarboxylic acids used were formic acid, acetic acid and propionic acid. Acrylic acid, butyric acid, isooctanoic acid, benzoic acid. The synthesized Zr-MOFs was characterized by X-ray diffraction of powder, physical adsorption of N2 by scanning electron microscope, thermogravimetric analysis and so on. It was found that Zr-MOFs materials with good morphology could be synthesized by adding other carboxylic acids except formic acid. However, different monocarboxylic acids affect the crystallinity, grain size and specific surface area of Zr-MOFs materials. Levulinic acid is a kind of biomass-platform molecule with great application value, and it is the basic raw material for the synthesis of various light chemical products. The separation and purification of the product is an important problem in the preparation of levulinic acid. In this experiment, UiO-66 UiO-67 and UiO-66-NH2 were used as adsorbents to adsorb levulinic acid aqueous solution respectively. It was found that UiO-66 and UiO-66-NH2 could adsorb levulinic acid. A series of studies on the adsorption of levulinic acid by UiO-66 were carried out on the basis of UiO-66, such as the adsorption rate of UiO-66 on levulinic acid, the effect of concentration and temperature of levulinic acid solution on the ability of UiO-66 to adsorb levulinic acid. It was found that when the concentration of levulinic acid solution was 70.0 mg/mL, the saturated adsorption capacity of UiO-66 could reach 291 mg / g. At the same time, the industrial production environment of levulinic acid was simulated. Furfuryl alcohol and formic acid were added to the aqueous solution of levulinic acid. It was found that the selective adsorption of levulinic acid by UiO-66 was stronger. The presence of furfuryl alcohol and formic acid had little effect on the ability of UiO-66 to adsorb levulinic acid. The desorption and regeneration experiments of the adsorbed UiO-66 crystal were carried out. It was found that after 5 times of desorption and regeneration, the crystal skeleton was intact, and the adsorptive capacity of levulinic acid was still high, and it could be used repeatedly.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4;TB383.4

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