Polyimide membranes,owing to their robust polymer backbone and facile structural tunability,are extensively used for H_(2)/CO_(2)separation.However,efficient H_(2)separation remains challenging because of the wide por...Polyimide membranes,owing to their robust polymer backbone and facile structural tunability,are extensively used for H_(2)/CO_(2)separation.However,efficient H_(2)separation remains challenging because of the wide pore size distribution within the chain-packed structure of conventional polyimides.Here,we propose a coordination crosslinking engineering strategy,where Pd^(2+) is incorporated into an alkynyl-based polyimide containing carboxyl groups to generate coordination cross-linked networks in situ.The formed coordination bonds significantly reduce the interchain d-spacing and restrict the mobility of the polymer chains,thereby enhancing size-sieving ability.Additionally,the presence of Pd^(2+) significantly increases the affinity of membrane for H_(2).Based on their synergistic effect,the optimized EBPA-TB-COOH@Pd^(2+)-6 membrane(EBPA:4,4′-(ethyne-1,2-diyl)diphthalic anhydride;EBPA-TB-COOH:alkynyl-based polyimide polymer)exhibits an unprecedented combination of high H_(2)permeability(512.5 bar)and excellent H_(2)/CO_(2)selectivity(30.4),surpassing most polyimide membranes reported to date.Furthermore,the coordination crosslinking networks endow the membranes with high and stable H_(2)/CO_(2)separation performance under a wide operating pressure range(1 to 6 bar).This coordination crosslinking engineering strategy offers an effective approach for designing next-generation polyimide membranes for hydrogen recovery and purification.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.22278178)the Natural Science Foundation of Xinjiang Uygur Autonomous Region,China(Grant No.2022D01D030)+1 种基金the National Science Foundation of Jiangsu Province,China(Grant No.BK20230106)the Fundamental Research Funds for the Central Universities,China(Grant No.JUSRP622035)。
文摘Polyimide membranes,owing to their robust polymer backbone and facile structural tunability,are extensively used for H_(2)/CO_(2)separation.However,efficient H_(2)separation remains challenging because of the wide pore size distribution within the chain-packed structure of conventional polyimides.Here,we propose a coordination crosslinking engineering strategy,where Pd^(2+) is incorporated into an alkynyl-based polyimide containing carboxyl groups to generate coordination cross-linked networks in situ.The formed coordination bonds significantly reduce the interchain d-spacing and restrict the mobility of the polymer chains,thereby enhancing size-sieving ability.Additionally,the presence of Pd^(2+) significantly increases the affinity of membrane for H_(2).Based on their synergistic effect,the optimized EBPA-TB-COOH@Pd^(2+)-6 membrane(EBPA:4,4′-(ethyne-1,2-diyl)diphthalic anhydride;EBPA-TB-COOH:alkynyl-based polyimide polymer)exhibits an unprecedented combination of high H_(2)permeability(512.5 bar)and excellent H_(2)/CO_(2)selectivity(30.4),surpassing most polyimide membranes reported to date.Furthermore,the coordination crosslinking networks endow the membranes with high and stable H_(2)/CO_(2)separation performance under a wide operating pressure range(1 to 6 bar).This coordination crosslinking engineering strategy offers an effective approach for designing next-generation polyimide membranes for hydrogen recovery and purification.
