MOFs衍生金属纳米粒子和氮掺杂多孔碳的制备与应用

发布时间：2018-04-29 04:12

本文选题：金属有机骨架化合物 + 金属纳米粒子　；参考：《吉林大学》2017年硕士论文

【摘要】：金属有机骨架(Metal-organic-frameworks,MOFs)化合物是由金属原子中心与有机配体通过自组装共同构筑而成的新型多孔晶体材料。与传统的多孔材料相比,MOFs具有高比表面和高孔隙率等特点,这使得MOFs在能源储存、气体分离以及催化等多方领域都有较大的应用潜能。另一方面,由于MOFs的高度有序多孔骨架结构中包含有大量的有机配体,因此MOFs被认为是最理想的模板之一,用以在高温条件下衍生出多功能的多孔碳材料。MOFs具有多变性和可调性,可以通过简单的变换金属节点或有机配体的方法来实现对其结构的调节。当选择稳定的金属离子(如Fe、Co、Ni等)作为MOFs前驱体的中心,在合适的碳化条件下可制备包裹金属纳米粒子的多孔碳材料。若选择易挥发的Zn离子作金属中心或含氮有机配体,在惰性氛围中可衍生出无金属的氮掺杂多孔碳材料。本论文以MOFs为模板,在不同碳化条件下,制备碳包裹金属粒子材料或氮掺杂多孔碳材料,并研究它们分别在催化、染料吸附中的性能:论文第二章通过合理调节JUC160的金属中心Co/Zn的比例,成功合成一系列单金属和多变量金属中心的JUC160,以此为前驱体在高温下原位碳化得到一系列包裹金属钴粒子的多孔碳材料。将碳化得到的产物应用于4-硝基苯酚的催化加氢还原反应中,测试结果表明当JUC160前驱体中金属中心Co和Zn的比例为1比1时,所衍生出的碳包裹金属粒子材料具有最高催化活性。论文第三章主要以纳米Zn-JUC160为模板,在惰性氛围中进行高温碳化制备多孔碳材料,并研究其对于亚甲基蓝染料的吸附性能。由于纳米Zn-JUC160以Zn离子为金属中心,所以在碳化过程中生成的ZnO可被C还原为Zn,在高于沸点的温度下被蒸发并随惰性气体流走。而纳米Zn-JUC160的有机配体——苯并咪唑和2-甲基苯并咪唑均含大量氮元素,所以它在高温下碳化可得到氮掺杂的多孔碳材料。氮气吸附-脱附实验结果表明纳米Zn-JUC160衍生的氮掺杂多孔材料具有较高比表面积和合理的孔道结构,这十分有利于其在染料吸附方面的应用。在亚甲基蓝的吸附研究中,各项结果表明所制备氮掺杂多孔碳材料是很好的吸附剂。总的来说,本论文合理选择MOFs为前驱体,根据有效的碳化办法和碳化条件,成功合成碳包裹金属粒子材料或氮掺杂多孔碳材料。制备的多功能碳材料分别在催化、染料吸附方面表现出优异的性能。本论文不仅提供了MOFs衍生碳包裹金属粒子材料或氮掺杂多孔碳材料的有效合成方法,并对材料的组成、结构和性能进行了系统的研究,具有一定的学术意义和应用价值。
[Abstract]:Metal-organic-frameworksMOFs) compounds are new porous crystal materials constructed by self-assembly of metal atom centers and organic ligands. Compared with the traditional porous materials, MOFs have the characteristics of high specific surface and high porosity, which makes MOFs have great application potential in many fields such as energy storage, gas separation and catalysis. On the other hand, MOFs is considered to be one of the most ideal templates for MOFs because it contains a large number of organic ligands in its highly ordered porous skeleton. The multifunctional porous carbon materials (MOFs) derived at high temperature have the characteristics of variability and tunability, and their structure can be adjusted by simply changing metal joints or organic ligands. When stable metal ions (such as Febco Ni) are selected as the centers of MOFs precursors, porous carbon materials encapsulating metal nanoparticles can be prepared under suitable carbonization conditions. If the volatile Zn ion is chosen as the metal center or the organic ligands containing nitrogen, the metal-free N-doped porous carbon materials can be derived in the inert atmosphere. In this thesis, carbon encapsulated metal particles or nitrogen-doped porous carbon materials were prepared under different carbonization conditions using MOFs as template. Performance in Dye adsorption: chapter 2 of this paper, by adjusting the proportion of Co/Zn in the metal center of JUC160, A series of single metal and multivariable metal centers JUC160 have been successfully synthesized, which can be used as precursors for in-situ carbonization at high temperature to obtain a series of porous carbon materials encapsulating cobalt particles. The carbonized product was applied to the catalytic hydrogenation of 4-nitrophenol. The results showed that the ratio of Co and Zn in the JUC160 precursor was 1: 1. The derived carbon encapsulated metal particles have the highest catalytic activity. In the third chapter, porous carbon materials were prepared by carbonization in inert atmosphere using nanometer Zn-JUC160 as template, and their adsorption properties for methylene blue dyes were studied. Due to the Zn ion as the metal center, the ZnO formed in the carbonization process can be reduced to Zn by C, and evaporated at a temperature higher than the boiling point, and then flow along with the inert gas. The organic ligands of nanometer Zn-JUC160, benzimidazoles and 2-methylbenzimidazole, contain a lot of nitrogen elements, so they can be carbonized at high temperature to obtain nitrogen-doped porous carbon materials. The results of nitrogen adsorption-desorption experiment show that the nitrogen-doped porous materials derived by nanometer Zn-JUC160 have high specific surface area and reasonable pore structure, which is very helpful for their application in dye adsorption. In the study of methylene blue adsorption, the results show that the nitrogen doped porous carbon material is a good adsorbent. In general, MOFs was chosen as the precursor in this paper. According to the effective carbonization method and carbonation conditions, carbon encapsulated metal particle materials or nitrogen-doped porous carbon materials were successfully synthesized. The multifunctional carbon materials showed excellent performance in catalysis and dye adsorption. This paper not only provides an effective synthesis method for MOFs derived carbon coated metal particles or nitrogen-doped porous carbon materials, but also systematically studies the composition, structure and properties of the materials, which has certain academic significance and application value.
【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】：O613.71;TB383.4

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