Effect of Water for the Synthesis of Cyclic Carbonate from Epoxide and CO2 Using Mg-MOF-74

In this study, M-MOF-74 (M = Mg, Ni, Zn) materials were prepared to use as heterogeneous catalysts for synthesis of cyclic carbonate from epoxide and carbon dioxide (CO2) in the presence of water. The XRD results indicated that the main peaks of synthesized M-MOF-74 were well matched with those of simulated one. FE-SEM images showed the hexagonal prism or flower micro/nanostructure proving that M-MOF-74 is successively synthesized. H2O/PO ratio, reaction temperature and CO2 pressure affected the propylene oxide (PO) conversion and propylene carbonate (PC) selectivity. The addition of solvent containing hydroxyl group, which cause ring opening of PO, led to increase of PO conversion. The Mg-MOF-74 had higher water stability than others because of the less elongation of O-M bond caused by OH and H dissociated from H2O.