含多金属氧酸盐的金属—有机框基膜材料的制备及其催化氧化性能的研究

发布时间：2018-04-22 13:50

本文选题：杂多酸 + 金属有机框架　；参考：《吉林农业大学》2015年硕士论文

【摘要】：金属-有机框架(metal-organic frameworks,MOFs)化合物是由金属离子与有机配体通过自组装过程杂化生成的一类具有周期性多维网状结构的多孔晶体材料。杂多酸(Heteropolyacid),也称多金属氧簇,是一类由氧原子桥接金属原子形成的金属-氧簇化合物。前者作为一种多孔的结晶材料在催化、吸附分离、传感、磁性和其他方面具有广泛的潜在应用。后者由于其组成和结构的多样,性质的可调性,在光、电、磁学、催化和药物等领域有着重要的应用。鉴于上面的现状,包含杂多酸的金属-有机框架杂化膜材料的研究将成为人们关注的热点课题,并且其成膜的可能性已得到了实验和理论的证实。本文制备了四种包含不同杂多酸的金属-有机框架膜材料,并对其合成方法、形貌特征、化学结构、催化性能进行了深入探讨,主要研究结果如下:1、四种杂多酸的合成在环境开放的条件下,通过酸化加热乙醚萃取的方法合成了四种经典的keggin型的杂多酸,分别是H3PW12O40、H3PMo12O40、H3SiW12O40、H3Si Mo12O40。这四种杂多酸具有类似的化学结构、性质特征和结构稳定性,是高效的双功能催化剂,既是酸催化剂,又是氧化还原催化剂。并且可以应用在非均相催化和均相催化反应中,具有良好的环境友好性,对环境无污染。2、分别含有四种多金属氧酸的金属-有机框架膜材料的制备本论文选择被广泛研究的多孔金属有机框架化合物HKUST-1(Cu3(BTC)2)作为框架材料。采用原位晶化法,在常温条件下以铜网为载体合成了四种包含不同杂多酸的金属有机框架膜材料,PMo@Cu3(BTC)2、SiMo@Cu3(BTC)2、PW@Cu3(BTC)2、SiW@Cu3(BTC)2。合成的膜材料厚度在8μm左右,表面晶粒尺寸均一。铜网在合成过程中既是载体又是铜离子源,采用的溶剂是水和乙醇体积比为1:1的混合溶剂,这样有利于杂多酸和均苯三甲酸的充分溶解。在合成过程创新性的中加入了过氧化氢,能够有效的加快膜材料的生长进程。并且对过氧化氢的最适添加量做出了探索。3、金属-有机框基膜材料的催化氧化性能研究以罗丹明B为目标降解物,四种金属有机框架膜材料都表现出了高效的催化性能,在反应进行到100min时,催化降解率都在96%以上,并且能够良好的重复使用,使用多次催化性能无明显下降。这类催化剂结合了多酸和金属有机框架化合物的优点,与传统催化剂相比具有以下优点:具有明确的X-ray晶体学结构;更高的催化效率;克服了流失和钝化现象;均匀的孔道结构可以选择性的催化化学反应;稳定的框架结构和在载体上的牢固负载更有利于催化剂的回收和循环利用。
[Abstract]:Metal-organic framework metal-organic frameworks (MOFs) compounds are a kind of porous crystal materials with periodic multi-dimensional network structure formed by self-assembly process of metal ions and organic ligands. Heteropoly acido, also called polymetallic oxygen cluster, is a kind of metal-oxygen cluster compound formed by oxygen atom bridging metal atom. The former as a porous crystalline material has a wide range of potential applications in catalysis, adsorption, separation, sensing, magnetic and other fields. The latter has important applications in the fields of light, electricity, magnetics, catalysis and medicine because of its diverse composition and structure and adjustable properties. In view of the above situation, the study of metal-organic frame hybrid membrane materials containing heteropoly acids will become a hot topic, and the possibility of membrane formation has been confirmed by experiments and theories. In this paper, four kinds of metal-organic framework membrane materials containing different heteropoly acids were prepared, and their synthesis methods, morphology, chemical structure and catalytic properties were discussed. The main results are as follows. Four kinds of heteropoly acids, H3PW12O40H3PMo12O40H3SiW12O40H3SiMo12O40H3SiMo12O40H3SiMo12O40H3SiMo12O40H3SiMo12O40H3SiMo12O40H3SiMo12O40H3SiMo40H3SiMo40H3SiMo40H3SiMo40H3SiMo40H3SiMo40H3SiMo40H3SiMo@@ These four heteropoly acids have similar chemical structure, properties and structural stability. They are highly effective bifunctional catalysts, both acid catalyst and redox catalyst. And can be used in heterogeneous catalysis and homogeneous catalytic reactions, with good environmental friendliness, Preparation of metal-organic framework membrane materials containing four kinds of polyoxometallic acids without environmental pollution. In this paper, the porous organometallic framework compound HKUST-1Cu3BT-2 was selected as the framework material. Four kinds of metal-organic frame membrane materials containing different heteropoly acids were synthesized by in situ crystallization under normal temperature with copper mesh as the carrier. Four kinds of metal-organic framework membrane materials containing different heteropoly acids were synthesized. The thickness of the synthesized film is about 8 渭 m and the surface grain size is uniform. Copper mesh is both a carrier and a copper ion source in the process of synthesis. The solvent used is a mixture of water and ethanol at 1:1 volume ratio, which is beneficial to the full dissolution of heteropoly acid and terephthalic acid. The addition of hydrogen peroxide into the synthesis process can effectively accelerate the growth process of the membrane materials. The optimum addition amount of hydrogen peroxide was explored. The catalytic oxidation performance of metal-organic frame membrane materials was studied. Rhodamine B was taken as the target degradation material. The four kinds of organometallic frame membrane materials showed high catalytic performance. The catalytic degradation rate was above 96% when the reaction was carried out to 100min, and it could be reused well. This kind of catalyst combines the advantages of polyacid and organometallic framework compounds, and has the following advantages compared with traditional catalysts: clear X-ray crystallographic structure, higher catalytic efficiency, overcome loss and passivation phenomena; The uniform pore structure can selectively catalyze the chemical reaction, and the stable frame structure and the solid loading on the support are more favorable to the recovery and recycling of the catalyst.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2

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