胺基功能化的金属—有机骨架材料的制备及性能研究

发布时间：2018-02-13 07:46

本文关键词： 金属-有机骨架材料胺基后合成修饰开放金属位点气体分离膜 H_2/CO_2分离　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着全球人口增长和工业化的推进,世界对能源的需求量不断攀升。不可再生的化石燃料无论从数量上还是清洁程度上都与我们当下的现代化生产要求相距甚远。越来越多的研究者开始将探索的触角延伸到可再生的新能源的开发上来。氢气,作为一种清洁环保、高热值的新型能源,显示出了很高的应用价值。然而,就目前的技术来看,想要大规模地利用氢气主要面临着以下几个问题:其一、不能从自然界中直接获得氢气,必须研发一种高效、绿色、环保的制备氢气的方法。其二、就现有的制备工艺来看,无论是蒸汽重整反应还是水汽转换的方法都不可避免的造成氢气中混有一定量的二氧化碳。捕获二氧化碳进而纯化氢气,可以有效地增加燃料的热值。相较于传统的分离方法,譬如变压吸附(PSA)和低温蒸馏,膜分离技术具有低能耗、低成本和易于操作等优点。目前市场上,应用较为广泛的膜材料当属制备成本低的聚合物膜材料,但是聚合物膜材料一直面临着稳定性不高,以及通量和选择性很难同时达到分离要求等问题。作为有序的多孔材料,沸石分子筛膜材料凭借其良好的孔道结构和极优的稳定性,已经成为得到了广泛的实际应用。金属-有机骨架材料(Metal Organic Frameworks,MOFs)是一种新型无机-有机晶体材料,它具有较高的比表面积、规则的孔道结构以及孔道易调节和功能化等优势,在气体存储和分离、催化等领域具有极高的应用价值,近几年成为了国内外的又一大研究热点材料。MOFs材料是由金属中心或者金属簇与有机配体自组装而成的多孔晶体材料。有些MOFs材料经过活化处理,可以去除与金属中心配位的端基分子,从而形成高密度的开放金属位点(open metal sites,OMSs),也称之为不饱和金属中心。其中,HKUST-1是最具有代表性的这类材料之一。我们通过向HKUST-1材料中的开放金属铜位点引入烷基胺官能团,从而实现了对HKUST-1材料的孔道功能化修饰。此外,基于胺基对二氧化碳的作用力,提高了HKUST-1材料对二氧化碳的吸附能力。进一步,我们将这一研究引入到了MOFs分离膜材料的后合成修饰,利用不同种类的烷基胺对HKUST-1膜材料进行后合成修饰,并且对修饰前后膜材料的H2/CO2的分离性能进行了对比研究。本论文,以功能为导向,利用晶体工程学理论,从结构的孔道功能化到膜材料的后合成修饰,从气体吸附到混合组分的气体分离,对具有开放金属位点的金属-有机骨架材料(MOFs)进行了较为系统的研究。
[Abstract]:As global population growth and industrialization advance, The world's demand for energy is rising. The amount and cleanliness of non-renewable fossil fuels are far from our current requirements for modern production. More and more researchers are beginning to explore. The angle extends to the development of renewable new energy. Hydrogen, As a clean, environmentally friendly, high-calorific energy source, it has shown great application value. However, in terms of current technology, there are several main problems to be faced with using hydrogen on a large scale: first, If you can't get hydrogen directly from nature, you have to develop a highly efficient, green and environmentally friendly method for hydrogen production. Second, from the point of view of the existing preparation process, Both steam reforming and steam conversion inevitably result in a certain amount of carbon dioxide mixed in hydrogen. Capturing carbon dioxide and purifying hydrogen can effectively increase the calorific value of fuel. For example, pressure swing adsorption (PSA) and low temperature distillation, membrane separation technology has the advantages of low energy consumption, low cost and easy to operate. However, the polymer membrane materials have been faced with low stability, and the flux and selectivity are difficult to meet the separation requirements. As an ordered porous material, zeolite molecular sieve membrane materials have excellent pore structure and excellent stability. The metal-organic skeleton material Organic frameworks (MOFs) is a new kind of inorganic and organic crystal material, which has high specific surface area, regular pore structure, easy adjustment and functionalization of pores, etc. It has high application value in gas storage and separation, catalysis and other fields. In recent years, MOFs have become another hot research material at home and abroad. MOFs are porous crystal materials composed of metal centers or metal clusters self-assembled with organic ligands. Some MOFs materials have been activated. The end molecules that coordinate with the metal center can be removed. Thus forming a high density open metal site, also known as the unsaturated metal center. Among these materials, metal UST-1 is one of the most representative. We introduce alkylamine functional groups into the open metal copper sites in HKUST-1 materials. In addition, based on the force of amine group on carbon dioxide, the adsorption ability of HKUST-1 material to carbon dioxide is improved. We introduced this research into the post-synthetic modification of MOFs membrane materials, and used different kinds of alkylamine to modify HKUST-1 membrane materials, and compared the separation properties of H _ 2 / CO _ 2 between the modified and modified membranes. Based on the theory of crystal engineering, functionally oriented, from structural pore functionalization to post-synthetic modification of membrane materials, from gas adsorption to gas separation of mixed components, The metal-organic skeleton materials with open metal sites (MOFs) were systematically studied.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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