Chem Sci. 2023 Jan 18;14(6):1472-1478. doi: 10.1039/d2sc06699h. eCollection 2023 Feb 8.
The modern technology for acetylene production is inevitably accompanied by the contamination of carbon dioxide and moisture impurities. Metal-organic frameworks (MOFs), with rational configurations of fluorine as the hydrogen-bonding acceptor (HBA), exhibit excellent affinities to capture acetylene from the gas mixtures. Currently, most research studies feature anionic fluorine groups as structural pillars (e.g., SiF6 2-, TiF6 2-, NbOF5 2-), whereas in situ insertion of fluorine into metal clusters is rather challenging. Herein, we report a unique fluorine-bridged Fe-MOF, i.e., DNL-9(Fe), which is assembled by mixed-valence FeIIFeIII clusters and renewable organic ligands. The fluorine species in the coordination-saturated structure offer superior C2H2-favored adsorption sites facilitated by hydrogen bonding, with a lower C2H2 adsorption enthalpy than other reported HBA-MOFs, demonstrated by static/dynamic adsorption tests and theoretical calculations. Importantly, DNL-9(Fe) shows exceptional hydrochemical stability under aqueous, acidic, and basic conditions, and its intriguing performance for C2H2/CO2 separation was even maintained at a high relative humidity of 90%.
PMID:36794184 | PMC:PMC9906641 | DOI:10.1039/d2sc06699h