Crown ether-based covalent organic frameworks for CO2 fixation

Abstract

With the development of industrial production, the excessive accumulation of CO₂ has caused many environmental problems. The catalytic cycloaddition of CO₂ to epoxides is the most promising and green pathway for CO₂ utilization. Thus, a new crown ether-based covalent organic framework (ETTA-B₁₈C₆-COF) was synthesized by a solvothermal method. The quadrupole moment interaction between the ether-oxygen groups on crown ether-based COF and CO₂ made it a potential platform for CO₂ cycloaddition. Its catalytic performance was evaluated by the cycloaddition reaction of 1,2-epoxyhexane and CO₂. Under the optimized conditions, 90% conversion of epoxide and >99% selectivity of the adduct were achieved. Moreover, this catalyst exhibited satisfactory stability and tolerance for diverse substrates. This novel catalyst may provide new enlightenment for the activation and utilization of CO₂.