金属有机骨架材料Cu-MOF的大气压冷等离子体活化及性能研究

发布时间：2018-05-04 05:09

本文选题：金属有机骨架材料 + Cu-MOF　；参考：《大连大学》2017年硕士论文

【摘要】：金属有机骨架材料(MOFs)是一种新型多孔材料,因其比表面积大等特点而被广泛应用于催化、气体吸附与分离等多种领域。在金属有机骨架材料的合成过程中均需通过活化处理去除其结构内的客体分子并得到活性位点。现有研究中大多采用加热处理或者溶剂交换与加热处理相结合的活化方式,分别称为热活化法和溶剂交换法。其中关于热活化法已有相关研究讨论了不同活化温度的影响,而对于其他因素如活化气氛的影响等未见报道。溶剂交换法虽然可有效去除孔道内的客体分子,但活化过程所需时间较长且需借助有机溶剂,如氯仿、甲醇等,存在污染和有毒问题。本论文首先合成了一种铜基金属有机骨架材料(Cu-MOF),采用X射线衍射仪(XRD)、N2吸附脱附、热重测试(TG)及扫描电子显微镜(SEM)等对其晶体结构、孔结构、热稳定性及表面形貌等进行了表征。结果表明合成的Cu-MOF是一种比表面积为1102.9m2·g-1的多孔材料,具有正八面体构型,晶粒大小约为10μm,热稳定温度约为300oC。其次,以自制的Cu-MOF为研究对象考察了热活化过程中活化气氛和活化温度对其结构和性能的影响。结果表明:活化气氛对Cu-MOF的结构及CO催化转化活性有重要影响。在本实验所考察的四种活化气氛(Ar、O2、CO标准气及H2)中,O2及CO标准气(1%CO、20%O2及79%N2)均可有效提高Cu-MOF的CO催化转化活性,Ar及H2的活化作用则较弱。另一方面,活化温度较低或过高均不能有效提高Cu-MOF的CO催化转化活性。本实验所得最佳活化气氛为CO标准气,最佳热活化温度为240oC。此外,本论文还进行了大气压冷等离子体活化Cu-MOF的相关研究,并以商品化Cu-MOF为载体负载过渡金属,通过大气压冷等离子体进行活化处理,考察了过渡金属类型及负载量对样品结构和性能的影响。研究表明:(1)冷等离子体可有效降低Cu-MOF的CO起始转化温度;(2)负载不同过渡金属对Cu-MOF的CO催化转化活性有较大差异,在Fe、Co、Ni、Cu和Zn这五种过渡金属中,负载Fe时样品的CO催化转化活性最高,且最佳负载量为7%。
[Abstract]:Organometallic skeleton (MOF) is a new porous material, which is widely used in many fields such as catalysis, gas adsorption and separation because of its large specific surface area. In the process of synthesis of organometallic skeleton materials, the active sites are obtained by removing the guest molecules in the structure of organometallic skeleton materials through activation treatment. Most of the existing researches use heating treatment or the combination of solvent exchange and heating treatment, which are called thermal activation method and solvent exchange method respectively. The influence of different activation temperature on the thermal activation method has been discussed, but the influence of other factors, such as the activation atmosphere, has not been reported. Although the solvent exchange method can effectively remove the guest molecules in the channels, the activation process takes a long time and requires organic solvents, such as chloroform, methanol, etc., which have the problems of pollution and toxicity. In this paper, a copper-base metal-organic skeleton material, Cu-MOF, was synthesized. The crystal structure, pore structure, thermal stability and surface morphology were characterized by X-ray diffractometer (XRD), thermogravimetric measurement (TG) and scanning electron microscopy (SEM). The results show that the synthesized Cu-MOF is a porous material with a specific surface area of 1102.9m2 g-1, with a normal octahedron configuration, a grain size of about 10 渭 m and a thermal stability temperature of about 300oC. Secondly, the effects of activation atmosphere and activation temperature on the structure and properties of Cu-MOF were investigated. The results show that the activation atmosphere has an important effect on the structure of Cu-MOF and the catalytic activity of CO. In the four activated atmospheres investigated in this experiment, the activity of CO catalytic conversion activity, ar and H _ 2, can be improved effectively by O _ 2 and CO _ (1) and CO _ (20) O _ 2 and 79N _ 2) in the four kinds of activated atmospheres, and H _ 2). On the other hand, low or too high activation temperature can not effectively improve the CO catalytic conversion activity of Cu-MOF. The best activation atmosphere is CO standard gas and the optimum thermal activation temperature is 240 OC. In addition, the paper also studied the activation of Cu-MOF by atmospheric pressure cold plasma. The commercial Cu-MOF was used as carrier to support transition metal, and the activated metal was treated by atmospheric cold plasma. The effects of transition metal type and loading amount on the structure and properties of the samples were investigated. The results show that the cold plasma can effectively reduce the CO conversion temperature of Cu-MOF. The catalytic activity of different transition metals for CO conversion of Cu-MOF is quite different. The CO catalytic conversion activity of the sample is the highest when Fe is loaded, and the optimum loading amount is 7%.
【学位授予单位】：大连大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.4;O643.36

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