Gadolinium-Based Metal–Organic Framework as an Efficient and Heterogeneous Catalyst To Activate Epoxides for Cycloaddition of CO₂ and Alcoholysis

Abstract

Development of heterogeneous catalysts for the cycloaddition of CO2 with epoxides to prepare cyclic carbonates is a hot topic in the field of CO2 transformation. Herein, a rare-earth-metal gadolinium-based metal–organic framework (Gd-MOF) was synthesized from GdCl3 and pyromellitic dianhydride in N,N-dimethylformamide, which was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption, and Fourier transform infrared (FT-IR) spectroscopy. The synthesized Gd-MOF could be used as heterogeneous catalyst for the cycloaddition of CO2 with epoxides in the presence of quaternary ammonium salts, and Gd-MOF/n-Bu4NBr showed the best performance for the cycloaddition of CO2 with various epoxides to form the corresponding cyclic carbonates due to the excellent synergetic effect. Furthermore, the prepared Gd-MOF could be used as heterogeneous catalyst for alcoholysis of various epoxides to form β-alkoxy alcohols effectively.