Multifunctional metal-organic frameworks for direct photosynthesis of cyclic carbonates from gaseous olefins
Abstract
Ethylene carbonate (EC) and propylene carbonate (PC) are important feedstocks in the production of commercial battery electrolytes and green solvents. However, their conventional industrial synthetic pathways rely heavily on energy-intensive thermocatalytic processes with costly epoxide reactants. Here, we report a class of multifunctional metal-organic framework photocatalysts (RE-BTTD-AC) that integrate oxygen (O2) activation, C-H bond activation, photothermal conversion and Lewis acid reactivity. They enable photosynthesis of EC and PC under ambient conditions with a sustainable, cheap and safe method using ethylene (C2H4)/propylene (C3H6), CO2, and O2. Experimental results combined with theoretical calculations demonstrate that the multifunctional nature of RE-BTTD-AC permits the occurrence of tandem reaction of photoredox and cycloaddition, leading to a relay conversion of C2H4/C3H6-to-epoxide-to-EC/PC. The catalytic system exhibits high product yields (EC of 96.02 μmol/g/h with 95% selectivity, PC of 640.03 μmol/g/h with 93% selectivity) in 48 hours and has a long-term production capacity of at least 720 hours. A class of multifunctional metal-organic framework photocatalysts enable sustainable production of cyclic carbonates from gases olefins under ambient conditions with high yields and durability.