Thermodynamic−Kinetic Synergistic Separation of CH4/N2 on A Robust Aluminum-Based Metal−Organic Framework

作者：Feifei Zhang, Hua Shang, Bolun Zhai, Xiaoming Li, Yingying Zhang, Xiaoqing Wang, Jinping Li, Jiangfeng Yang · 年份：2022 · DOI：10.22541/au.166743918.82315855/v1 · 被引用次数：3 · 研究领域：Metal-Organic Frameworks: Synthesis and Applications、Covalent Organic Framework Applications、Carbon Dioxide Capture Technologies

A robust aluminum-based metal-organic framework (Al-MOF) MIL-120Al with 1D rhombic ultra-microporous was reported. The non-polar porous walls composed of para-benzene rings with a comparable pore size to the kinetic diameter of methane allow it to exhibit a novel thermodynamic-kinetic synergistic separation of CH4/N2 mixtures. The CH4 adsorption capacity was as high as 33.7 cm3/g (298 K, 1 bar), which is the highest uptake value among the Al-MOFs reported to date. The diffusion rates of CH4 were faster than N2 in this structure as confirmed by time-dependent kinetic adsorption profiles. Breakthrough experiments confirm that this MOF can completely separate the CH4/N2 mixture and the separation performance is not affected in the presence of H2O. Theoretical calculations reveal that pore centers with more energetically-favorable binding sites for CH4 than N2. The results of pressure swing adsorption (PSA) simulations indicate that MIL-120Al is a potential candidate for selective capture coal-mine methane.