Open metal site (OMS) and Lewis basic site (LBS)-functionalized copper–organic framework with high CO2 uptake performance and highly selective CO2/N2 and CO2/CH4 separation

Abstract

In this work, a multifunctional microporous metal–organic framework (MOF), [Cu₂(BPDC)₂(H₂O)₂]·5.6H₂O·DMA (1, BPDC = 5,5′-dicarboxylate-3,3′-dipyridine anion and DMA = dimethylacetamide), has been synthesized based on the ligand BPDC under solvothermal conditions. Single crystal X-ray analysis reveals that it possesses a non-interpenetrating binodal (4,4)-connected three-dimensional PtS-type network with the Schläfli point symbol of {4²·8⁴}. Remarkably, the activated 1 (1a) with dual functionalities of open metal sites (OMSs) and O-rich Lewis basic sites (LBSs) exhibits excellent CO₂ adsorption (193 cm³ g⁻¹ at 298 K) and high-effect separation ability (41.5 for CO₂/N₂ = 15/85 and 9.7 for CO₂/CH₄ = 5/95 under 1 bar at 298 K). Additionally, 1a exhibits impressive performance for I₂ sorption and release in solvents.