Conversion of CO2 into cyclic carbonates using an ionic porous organic cage

Abstract

The conversion of carbon dioxide (CO₂) into value-added chemicals offers a promising path for greenhouse gas utilization. Porous organic cages (POCs), an emerging subclass of porous materials, have shown great potential in catalysis, primarily as catalyst supports and stabilizers for metal nanoparticles (MNPs) to enhance their catalytic activity. Herein, we report the use of an ionic POC (OFT-RCC3⁶⁺6Br⁻) as a metal-free catalyst for the cycloaddition of CO₂ and epoxides, generating cyclic carbonates in high yields. This POC catalyst is highly efficient, achieving a maximum yield of up to 90% with a turnover number (TON) of 3000 without requiring reaction solvents. Moreover, with the synergistic effect of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), the catalytic performance can be further enhanced across a wide substrate range.