A new 2D lanthanum based microporous MOF for efficient synthesis of cyclic carbonates through CO2 fixation

Abstract

Metal–organic frameworks (MOFs) containing multiple carboxylate and sulfonate linkers together with positively charged rare earth metals can offer new opportunities in heterogeneous catalysis. The high efficiency of the CO₂ fixation reaction at low temperature and pressure over MOF-based catalysts is very challenging as it involves the renewable feedstock CO₂ as a C1 source for the synthesis of value-added fine chemicals. Here we develop a new microporous La(III) based MOF through the solvothermal reaction using 5-sulfoisophthalic acid as the ligand, and the resulting La-5-SIP-MOF showed a high catalytic activity for the synthesis of cyclic carbonates from epoxides through the CO₂ fixation reaction at room temperature and moderate (3–5 MPa) pressure. The optimum product yield was obtained in only 1 h reaction with the desired yield up to 98%. The La-5-SIP-MOF was characterized by using different analytical techniques such as single crystal X-ray diffraction, FTIR, PXRD, N₂ adsorption/desorption study, UHR-TEM, solid UV-vis spectroscopy and TGA. The recycling efficiency and the structural stability of this MOF catalyst is also very high, suggesting a sustainable future of this La-MOF in heterogeneous catalysis.