A Microporous Metal−Organic Framework for Separation of CO₂/N₂ and CO₂/CH₄ by Fixed-Bed Adsorption

Abstract

A microporous MOF Zn(BDC)(4,4'-Bipy)0.5 (MOF-508b, BDC = 1,4-benzenedicarboxylate, 4,4'-Bipy = 4,4'-bipyridine) was examined for the separation and removal of CO2 from its binary CO2/N2 and CO2/CH4 and ternary CO2/CH4/N2 mixtures by fixed-bed adsorption. With one-dimensional pores of about 4.0 × 4.0 Å to induce their differential interactions with the three components, MOF-508b exhibits highly selective adsorption to CO2 with the adsorption capacity of 26.0 wt % at 303 K and 4.5 bar. This is the first example of microporous MOFs for the separation and removal of CO2 from its binary and ternary mixtures by fixed-bed adsorption, establishing the feasibility of the emerging microporous MOFs for their potential applications in this very important industrial and environmental process.