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

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.