High-Performance Carbon Capture with Fluorine-Tailored Carbon Molecular Sieve Membranes.

Abstract

Increasing energy consumption and climate change present an urgent global challenge to achieve carbon neutrality, with CO₂ capture as a top priority. Among various carbon capture technologies, CO₂ membrane separation stands out for its simplicity and energy efficiency in applications including gas purification and industrial gas recovery. Herein, a series of fluorine-tailored porous carbon molecular sieve (CMS) membranes derived from precisely designed precursors, achieving a well-balanced high permeability and selectivity for CO₂ separation are developed. Incorporating bent terphenyl monomers and both aliphatic/aromatic trifluoromethyl groups disrupted dense chain packing and promoted pore formation with enhanced permeability and selectivity for CO₂ separation. The TFM-550 membrane, derived from a fluorinated stretched polymer backbone precursor, exhibits exceptional performance with a CO₂ permeability of 47 190 ± 3204 Barrer and a CO₂/N₂ selectivity of 28.3 ± 5.7, while TFM-800 presented a higher selectivity of 71.8 ± 11.5, surpassing the 2019 upper bound. Furthermore, under flue gas conditions (CO₂/O₂/N₂ = 1/1/4 in molar ratio), the CMS membrane demonstrate high CO₂ permeability of 36,204 ± 2,235 Barrer and outstanding CO₂/N₂ selectivity of 35.3 ± 1.8. The results here highlight the effectiveness of fluorine tailoring and the potential of fluorinated CMS membranes for sustainable industrial carbon capture applications.