Isomeric Separation of C6 Alkanes via Organic Solvent Reverse Osmosis with Covalent Organic Framework Membranes

作者：Hao Yang, Haoyuan Zhang, Zhengxuan Ji, Dongchen Shi, Chunqing Ji, Kexin Yu, Chengjun Kang, Dan Zhao · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c04063 · 被引用次数：26 · 研究领域：Covalent Organic Framework Applications、Metal-Organic Frameworks: Synthesis and Applications、Membrane Separation and Gas Transport

Membrane separation represents cutting-edge technology for the isomeric separation of C6 alkanes in the petrochemical sector. However, it remains challenging to design membranes with sub-0.1 nm resolution that can effectively discriminate between C6 alkane isomers. In this study, we report a molecularly selective, ultramicroporous covalent organic framework (COF) membrane featuring an accessible pore size of ∼4.5 Å for the isomeric separation of C6 alkanes. High permeance of 2.56 kg m –2 h –1 bar –1 together with a high selectivity of 70.9 are achieved for a binary separation of linear n -hexane ( n HEX) and branched 2,3-dimethylbutane (23DMB) through organic solvent reverse osmosis (OSRO). Notably, the research octane number (RON) of a five-component C6 alkane mixture can be effectively improved from 67.7 to 92.8 through a continuous separation using the COF membrane. The exceptional performance of the COF membrane suggests a new design of next-generation molecularly selective membranes toward efficient isomeric separation.