Chen Di-Ming, Sun Chun-Xiao, Zhang Nan-Nan, Si Huan-Huan, Liu Chun-Sen, Du Miao
Henan Provincial Key Lab of Surface & Interface Science , Zhengzhou University of Light Industry , Zhengzhou , 450002 Henan , China.
Inorg Chem. 2018 Mar 5;57(5):2883-2889. doi: 10.1021/acs.inorgchem.7b03278. Epub 2018 Feb 22.
As a modulatable class of porous crystalline materials, metal-organic frameworks (MOFs) have gained intensive research attention in the domain of gas storage and separation. In this study, we report on the synthesis and gas adsorption properties of two robust MOFs with the general formula Co(μ-OH)(cpt)Co(μ-OH)(L)(HO)(guests) [L = 3-amino-1,2,4-triazole (1) and 3,5-diamino-1,2,4-triazole (2); Hcpt = 4-(4-carboxyphenyl)-1,2,4-triazole], which show the same pacs topology. Both MOFs are isostructural to each other and show MIL-88-type frameworks whose pore spaces are partitioned by different functionlized trinuclear 1,2,4-triazolate-based clusters. The similar framework components with different amounts of functional groups make them an ideal platform to permit a systematic gas sorption/separation study to evaluate the effects of distinctive parameters on the CH uptake and separation performance. Because of the presence of additional amido groups, the MOF 2 equipped with a datz-based cluster (Hdatz = 3,5-diamino-1,2,4-triazole) shows a much improved CH uptake capacity and separation performance over that of the MOF 1 equipped with atz-based clusters (Hatz = 3-amino-1,2,4-triazole), although the surface area of the MOF 1 is almost twice than that of the MOF 2. Moreover, the high density of open metal sites, abundant free amido groups, and charged framework give the MOF 2 an excellent CH separation performance, with ideal adsorbed solution theory selectivity values reaching up to 11.5 and 13 for CH/CH (1:99) and CH/CO (50:50) at 298 K and 1 bar, showing potential for use in natural gas purification.
作为一类可调节的多孔晶体材料，金属有机框架（MOF）在气体存储和分离领域受到了广泛的研究关注。在本研究中，我们报道了两种通式为Co(μ-OH)(cpt)Co(μ-OH)(L)(HO)(客体) [L = 3-氨基-1,2,4-三唑(1)和3,5-二氨基-1,2,4-三唑(2); Hcpt = 4-(4-羧基苯基)-1,2,4-三唑]的坚固MOF的合成及其气体吸附性能，它们具有相同的pacs拓扑结构。两种MOF彼此同构，呈现出MIL-88型框架，其孔隙空间由不同功能化的基于三核1,2,4-三唑的簇分隔。具有不同官能团数量的相似框架组件使其成为一个理想的平台，可用于进行系统的气体吸附/分离研究，以评估不同参数对CH吸收和分离性能的影响。由于存在额外的酰胺基，配备基于datz的簇（Hdatz = 3,5-二氨基-1,2,4-三唑）的MOF 2比配备基于atz的簇（Hatz = 3-氨基-1,2,4-三唑）的MOF 1表现出显著提高的CH吸收能力和分离性能，尽管MOF 1的表面积几乎是MOF 2的两倍。此外，高密度的开放金属位点、丰富的游离酰胺基和带电框架赋予MOF 2优异的CH分离性能，在298 K和1 bar下，对于CH/CH（1:99）和CH/CO（50:50），理想吸附溶液理论选择性值分别高达11.5和13，显示出在天然气净化中的应用潜力。
