金属—有机骨架MOF-74系列吸附捕集低浓度二氧化碳的研究

发布时间：2018-05-20 02:07

本文选题：金属-有机骨架MOF-74 + CO_2吸附　；参考：《大连理工大学》2016年硕士论文

【摘要】：各种人类活动所排放的CO2正通过温室效应而致使全球变暖,该观点被广泛认同。回收C02有利于缓解温室效应,实现资源的优化利用。因此,迫切需要开发高效的C02吸附剂。金属-有机骨架材料是一种新型多孔材料,其在气体吸附分离领域表现出巨大的应用前景。MOF-74系列材料拥有蜂窝状网络拓扑结构,其一维六方孔道内布满了裸露的金属离子吸附位点,因而MOF-74对C02的吸附性能良好。以Mg-MOF-74为吸附剂,考察了原料气流速及吸附温度对C02吸附性能的影响。结果发现穿透时间与吸附量随着原料气流速以及吸附温度的升高而降低。Mg-MOF-74的吸附量随着温度的升高而下降,说明其对C02的吸附属于物理吸附,低温有利于C02的吸附。本文采用溶剂热法合成M-MOF-74系列材料(M=Cu, Zn, Co, Mn,Mg, Cd等),探究不同金属离子合成的MOF-74材料对CO2吸附能力的差异。在该系列材料中,Cu-MOF-74的吸附效果最差；Mg-MOF-74的吸附效果最佳,吸附性能远优于其他材料。对于溶剂热合成法制备的Mg-MOF-74,采用不同浓度的氨水溶液对其进行浸渍负载,探究不同浓度的浸渍氨水对改性后材料的CO2吸附性能的影响规律。结果表明氨水负载能够有效降低CO2浓度对材料吸附性能的影响,虽然氨负载导致材料比表面积减小,但是却提高了材料的单位表面积吸附量。氨负载有利于材料对低浓度CO2的吸附。在改性材料中,0.2mol/L氨水浸渍负载后的材料的吸附性能要优于原材料,其吸附量为200.5mg/g,与未浸渍原材料相比,吸附量提高5.6%。本文在常温常压下通过多组份的自组装合成出两种在一维孔道内含有-OH官能团的MOF-74衍生物,分别命名为Zn(OCA-OH)2(4,4'-bipy)0.5与Zn(MCA-OH)2(4,4'-bipy)0.5。衍生物的结构以及孔道尺寸与MOF-74一致。探究两种衍生物以及Zn-MOF-74对C02吸附能力的差异。结果表明,Zn(OCA-OH)2(4,4'-bipy)0.5与Zn(MCA-OH)2(4,4'-bipy)0.5材料对C02尤其是低浓度的C02的吸附性能,均优于Zn-MOF-74.并且对于3%CO2的吸附性能,Zn(MCA-OH)2(4,4'-bipy)0.5要略优于Zn(OCA-OH)2(4,4'-bipy)0.5。
[Abstract]:The idea that CO2 emissions from various human activities are warming the globe through Greenhouse Effect is widely accepted. Recovery of CO2 is helpful to alleviate Greenhouse Effect and realize optimal utilization of resources. Therefore, there is an urgent need to develop an efficient adsorbent C _ 2. The metal-organic skeleton material is a new porous material, which shows great application prospect in the field of gas adsorption and separation. The MOF-74 series of materials have honeycomb network topology. One dimensional hexagonal pore is filled with bare metal ion adsorption sites, so MOF-74 has good adsorption performance for CO2. The effects of gas flow rate and adsorption temperature on the adsorption properties of CO2 were investigated with Mg-MOF-74 as adsorbent. The results show that the adsorption capacity of Mg-MOF-74 decreases with the increase of gas velocity and adsorption temperature, indicating that the adsorption of CO2 is physical, and the low temperature is favorable to the adsorption of CO2. In this paper, M-MOF-74 series of materials, such as Cu, Zn, Co, MNO, mg, CD and so on, were synthesized by solvothermal method. The difference of the adsorption ability of MOF-74 materials synthesized by different metal ions to CO2 was investigated. The adsorption efficiency of Cu-MOF-74 is the worst and the adsorption performance of Mg-MOF-74 is much better than that of other materials. For Mg-MOF-74 prepared by solvothermal synthesis, different concentrations of ammonia solution were used to impregnate Mg-MOF-74, and the influence of different concentration of impregnated ammonia on the adsorption properties of modified CO2 was investigated. The results show that ammonia loading can effectively reduce the effect of CO2 concentration on the adsorption performance of the material. Although ammonia loading can reduce the specific surface area of the material, the adsorption amount per unit surface area of the material is increased. Ammonia loading is beneficial to the adsorption of CO2 with low concentration. The adsorption capacity of the modified material was better than that of the raw material after impregnated with ammonia water (0.2 mol / L). The adsorption capacity of the modified material was 200.5mg / g, which was increased by 5.6g / g compared with the unimpregnated raw material. In this paper, two kinds of MOF-74 derivatives containing -OH functional groups in one-dimensional channels have been synthesized by multicomponent self-assembly at room temperature and atmospheric pressure. The two derivatives are named ZnOCA-OHH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OHOH2OH2OH2OH2OH2OH2 and ZnMCA-OHH 2OHH 2OHP2OH2OH2OH2OH@@ The structure and pore size of the derivatives are consistent with that of MOF-74. To explore the difference of adsorption ability of two derivatives and Zn-MOF-74 for CO2. The results show that the adsorptive properties of ZnOCA-OHH2OH2OHH2OHH2OH2OHH2OH2OHH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2OH2 and ZnMCA-OHH2OH2OHH2OH2OHH2OH2OHH2 and ZnM@@ Moreover, the adsorption property of 3%CO2 is slightly better than that of OCA-OH2OH2OH2OH2OH2 (OHH2OH2) and 4K4 (4 / 4) -bipyrue (0.5) for the adsorption properties of 3%CO2 (Zn-OCA-OHH ~ (2 +).
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O647.3

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