Robust metal–organic framework with abundant large electronegative sites for removal of CO2 from a ternary C2H2/C2H4/CO2 mixture?

Inorganic Chemistry Frontiers Pub Date: 2022-08-10 DOI: 10.1039/D2QI01175A

Abstract

Separation of ternary gas mixtures is challenging and has rarely been achieved with a single porous solid material. Herein a trinuclear iron(III) based metal–organic framework (MOF) with high water stability, {[Fe3(μ3-O)(DFBDC)3(TPT)](OH)}n (JXNU-14) (DFBDC2? = 2,5-difluoroterephthalate and TPT = 2,4,6-tri(4-pyridinyl)-1,3,5-triazine), is applied for the removal of CO2 from a ternary C2H2/C2H4/CO2 mixture. The trigonal bipyramidal cavities and cylindrical cavities decorated with highly electronegative fluorine and oxygen atoms and abundant π rings in JXNU-14 offer stronger affinity for C2H2 and C2H4 than for CO2, resulting in the high-performance separation of a ternary equimolar mixture of C2H2, C2H4, and CO2, which is demonstrated by pure-component gas adsorption isotherms and actual column breakthrough experiments. The much stronger binding of C2H2 and C2H4 as compared to CO2 was further revealed by computational simulations. This work provides a useful strategy for the construction of MOFs possessing high-density electronegative sites for the efficient removal of CO2 from a ternary C2H2/C2H4/CO2 mixture.

Graphical abstract: Robust metal–organic framework with abundant large electronegative sites for removal of CO2 from a ternary C2H2/C2H4/CO2 mixture
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