Asghar Aisha, Iqbal Naseem, Aftab Leena, Noor Tayyaba, Kariuki Benson M, Kidwell Luke, Easun Timothy L
U.S.-Pakistan Center for Advanced Studies in Energy (USPCAS-E), National University of Sciences and Technology (NUST), H-12, Islamabad 44000, Pakistan.
School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad 44000, Pakistan.
R Soc Open Sci. 2020 Mar 25;7(3):191934. doi: 10.1098/rsos.191934. eCollection 2020 Mar.
Metal-organic frameworks (MOFs) based on 2,5-dihydroxyterepthalic acid (DOBDC) as the linker show very high CO uptake capacities at low to moderate CO pressures; however, these MOFs often require expensive solvent for synthesis and are difficult to regenerate. We have synthesized a Mn-DOBDC MOF and modified it to introduce amine groups into the structure by functionalizing its metal coordination sites with ethylenediamine (EDA). Repeat framework synthesis was then also successfully performed using recycled dimethylformamide (DMF) solvent. Characterization by elemental analysis, FTIR and thermogravimetric studies suggest that EDA molecules are successfully substituting the original metal-bound DMF. This modification not only enhances the material's carbon dioxide sorption capacity, increasing stability to repeated CO sorption cycles, but also improves the framework's stability to moisture. Moreover, this is one of the first amine-modified MOFs that can demonstrably be synthesized using recycled solvent, potentially reducing the future costs of production at larger scales.
以2,5-二羟基对苯二甲酸（DOBDC）为连接体的金属有机框架材料（MOFs）在低至中等CO压力下表现出非常高的CO吸附容量；然而，这些MOFs通常需要昂贵的溶剂进行合成，并且难以再生。我们合成了一种Mn-DOBDC MOF，并通过用乙二胺（EDA）对其金属配位位点进行功能化，将胺基引入结构对其进行了改性。然后，使用回收的二甲基甲酰胺（DMF）溶剂也成功地进行了重复的框架合成。通过元素分析、FTIR和热重研究表征表明，EDA分子成功地取代了原来与金属结合的DMF。这种改性不仅提高了材料的二氧化碳吸附容量，增加了对重复CO吸附循环的稳定性，而且还提高了框架对水分的稳定性。此外，这是首批可以用回收溶剂进行合成的胺改性MOFs之一，有可能降低未来大规模生产的成本。
