Design of carbonized melamine sponge@MOFs composites bearing diverse acid-base properties for boosting thermal and solar-driven CO2 cycloaddition

Integrating dual Lewis acid and base as well as rational hierarchical pore structure in one catalyst is favorable to significantly boost the CO 2 cycloaddition reaction at mild conditions. In this regard, carbonized melamine sponge (CMS) featuring a highly porous network, rich nitrogen doping and excellent photothermal capability is employed as the ideal host for the construction of CMS@MOFs (namely, MIL-88-NH 2 and ZIF-8-NH 2 ) composites with diverse acid-base properties. Results show that all the obtained composites exhibited a satisfactory CO 2 adsorbing capacity (33–54 cm 3 /g) and delivered a remarkable yield of target cyclic carbonate at either mild thermal conditions (0.1 MPa CO 2 and 80 o C) or under light irradiation (light intensity: ~350 mW/cm 2 ) at room temperature. Even with diluted CO 2 (15 vol. % CO 2 ), high yields of 80–82 % are achievable. Moreover, the used catalysts can be easily recycled from reaction systems, leading to a good recyclability .