Boosting Ethane/Ethylene Separation by MOFs through the Amino-Functionalization of Pores

Adsorption technology based on ethane-selective materials is a promising alternative to energy-intensive cryogenic distillation for separating ethane (C2H6) and ethylene (C₂H₄). We employed a pore engineering strategy to tune the pore environment of a metal–organic framework (MOF) through organic functional groups and boosted the C₂H₆/C₂H₄ separation of the MOF. Introduction of amino (−NH₂) groups into Tb-MOF-76 not only decreased pore sizes but also facilitated multiple guest-host interactions in confined pores. The NH₂-functionalized Tb-MOF-76(NH2) has increased C2H6 and C₂H₄ uptakes and C₂H₆/C₂H₄ selectivity. The results of experimental and simulated transient breakthroughs reveal that Tb-MOF-76(NH₂) has significantly improved one-step separation performance for C₂H₆/C₂H₄ mixtures with a high C2H4 (>99.95 %) productivity of 17.66 L kg−1 compared to 7.53 L kg⁻¹ by Tb-MOF-76, resulting from the suitable pore confinement and accessible −NH₂ groups on pore surfaces.