Adsorption-enhanced carbon membranes derived from copolyimide for ultrafast subangstrom discriminating CO<sub>2</sub> separation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41296846.
- Also identified by DOI 10.1126/sciadv.adv8650 and PMC identifier 12652326.
- Licence recorded as CC BY-NC.
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Abstract
Carbon membranes are emerging as a versatile platform for the selective separation of gas mixtures with similar molecular sizes. Here, a high-performance carbon membrane is developed from an asymmetric, rigid copolyimide precursor via a precisely controlled carbonization process. Membranes carbonized at 800°C exhibit exceptional CO<sub>2</sub> separation performance, with CO<sub>2</sub> permeabilities up to 15,700 barrer and CO<sub>2</sub>/N<sub>2</sub> and CO<sub>2</sub>/CH<sub>4</sub> selectivities of 63 and 52, respectively-surpassing the 2019 upper bounds. Molecular dynamic simulations, in conjunction with in situ thermogravimetric analysis-mass spectroscopy and thermogravimetric analysis-Fourier transform infrared spectroscopy, reveal the evolution of a bimodal carbon matrix with micropores (7 to 20 angstroms) and ultramicropores (4 to 7 angstroms). Gas transport is dominated by synergistic adsorption-selective and molecular sieving mechanisms, enabling subangstrom discrimination between CO<sub>2</sub> and larger gases. This work demonstrates a facile, tunable strategy to engineer carbon membranes with outstanding CO<sub>2</sub> separation capabilities, offering previously unexplored opportunities for energy-efficient gas separation processes in industrial applications.