Ligand-regulated synthesis of two cerium-based MOFs for catalytic conversion of CO2 into high-value-added chemicals.

The effective capture and conversion of CO2 into high-value chemicals are highly valuable and challenging. Herein, two cerium-based metal-organic frameworks (MOFs), compound 1 {Ce(HL1)(H2O)3}n and compound 2 {Ce(HL2)(H2O)2}n with 2D and 3D structures, respectively, were synthesized through ligand regulation and structurally characterized. Catalytic investigation demonstrated that the cycloaddition reaction between CO2 and aziridine can be catalyzed by compounds 1 and 2 at 60 °C and 1 MPa over 8 hours, affording oxazolidone yields of 95% and 99%, respectively. Obviously, they showed distinct differences in substrate adaptability. The combination of substrate activation experiments and 1H NMR spectroscopic characterizations confirms the synergistic effect between the Ce3+ active sites and co-catalyst TBAB, and a possible catalytic reaction mechanism is proposed. This work enriches the variety of catalytic rare-earth-based MOF materials.