Cobalt-based MOF nanoribbons with abundant O/N species for cycloaddition of carbon dioxide to epoxides

Abstract

Chemical fixation of CO2 with epoxides is an effective option to achieve sustainable synthesis of cyclic organic carbonates. Although metal–organic frameworks (MOFs) are promising catalysts for this reaction, their low stability in aqueous solutions makes this application infeasible. In an effort to overcome this limitation, cobalt-based metal–organic framework (Co(II)MOF) nanoribbons have been prepared by coordinating the Co(II) ions with a new ligand (C16H12N4O4) full of oxygen and nitrogen moieties. Strong chemical interactions occur between the adsorbed CO2 and oxygen/nitrogen atoms in this porous MOF structure. Co(II)-MOF nanoribbons with tetra-n-butylammonium bromide acted as cocatalysts with ∼97% yield of cyclic carbonate (reaction kinetic rate of 14.7 × 106 µmol g-1 h−1) upon the cycloaddition of epichlorohydrin (ECH) to CO2 (>99% reaction selectivity under solvent-free reaction condition at 80 °C, 3 h and 1 MPa CO2 pressure). This work may open a new avenue for chemical fixation of CO2 by rational design of the components and morphology of MOF-based catalysts.