Dual-Wing Ligand Constructed Metal–Organic Framework Membranes with Finely Tuned Apertures for Natural Gas Separation
Yapeng Shi1,2, Yang Liu1,2, Zhenggong Wang1,2,*, Weikang Lai1,2, Yining Liao1,2, Kuan Lu3, Zheng Niu1,2, Jian Jin1,2,*（靳健）
1 Soochow Univ, Coll Chem Chem Engn & Mat Sci, Innovat Ctr Chem Sci, Suzhou 215123, Peoples R China
2 Soochow Univ, Jiangsu Key Lab Adv Funct Polymer Design & Applica, Suzhou 215123, Peoples R China
3 Chinese Acad Sci, Inst Coal Chem, Country State Key Lab Coal Convers, Taiyuan 030001, Peoples R China
Adv. Funct. Mater.2024, 2404681
Metal-organic framework (MOF) membranes with apparent molecular sieving effects have great potential for gas separation. However, their application in light-gas separation (e.g., CO2/CH4 and H2/CH4) remains challenging due to their enlarged pore structures under transmembrane pressure. In this work, a series of MOF membranes constructed from dual-wing (DW) ligands including 2-chloromethylbenzimidazole, 2-methylbenzimidazole, 2-ethylbenzimidazole, and 2-phenylbenzimidazole are reported, to finely tune apertures and enhance molecule sieving property for small-size gases. These DW-ligands provide steric resistance in two directions perpendicular to the coordination bond, leading to a much finer pore structure. The introduction of the DW-ligands endows the DW/ZIF-8 membranes with an adjustable bottleneck door for regulating gas diffusion, blocking the transport of large-sized CH4 while allowing small-sized H2 and CO2 to permeate. The membranes show significantly improved molecular sieving property with a CO2/CH4 mixed-gas selectivity of 58.6 in the case of 2-chloromethylbenzimidazole23/ZIF-8, which represents the highest value among the reported ZIF membranes. This membrane also exhibits exceptional separation performance for H2/CH4 and H2/C3H8 with separation factors of 430 and 34341, which are the highest values among the reported MOF membranes. This study presents a facile and efficient strategy for regulating MOF aperture and constructing high-performance membranes for natural gas separation.
链接：https://onlinelibrary.wiley.com/doi/10.1002/adfm.202404681
