A highly stable cerium–organic framework: an efficient catalyst for the cycloaddition of CO2 and aziridines under mild-pressure

Abstract

Elevated concentrations of CO₂ in the atmosphere pose significant challenges, notably contributing to the greenhouse effect. CO₂ as an abundant C₁ resource converting into high-value oxazolidinones is a promising avenue for effective carbon fixation. Herein, a highly stable binuclear cerium–organic framework, [Ce₂(DCTP)₂(DMA)₂(OAc)₂]_n (1), has been successfully designed and synthesized, which maintains the intact three-dimensional framework after immersing in solutions with pH ranging from 1 to 12 and various common solvents for 24 hours, respectively. Explorations on CO₂ conversion indicate that compound 1 exhibits remarkable catalytic efficiency in the cycloaddition reaction of CO₂ with aziridines to form oxazolidinones under relatively low CO₂ pressure. 1 can be easily regenerated five times without a significant decrease in yield. Mechanistic experiments show that the high catalytic activity of 1 is attributed to the stable three-dimensional framework, high Lewis acidity, and ample cerium active sites. Notably, 1 is a rare lanthanide metal–organic framework-based (Ln-MOF-based) catalyst for the cycloaddition of CO₂ with aziridines under mild pressure.