Preparation of Schiff base metal catalyst and its catalytic synthesis of propylene carbonate from CO2

In recent years, research on the conversion of CO 2 into fine chemical products has emerged as a prominent and dynamic area of study. In this study, four ligands were synthesized using salicylaldehyde , o-phenylenediamine, ethylenediamine , hexanediamine, and 2,6-diaminopyridine as precursors. Subsequently, these ligands were reacted with cobalt nitrate, zinc chloride , and aluminum chloride to synthesize 12 Schiff base metal complexes , which were employed as catalysts for the synthesis of propylene carbonate from CO 2 and epichlorohydrin . The findings reveal that the SF-L/Co catalyst demonstrated superior performance, potentially attributed to the robust chelating capability of Co, leading to the provision of more acidic metal centers. Characterization of SF-L/Co was conducted utilizing scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) techniques. Process conditions were optimized, resulting in the achievement of a 100% yield and selectivity of propylene carbonate under optimal reaction conditions, without the generation of any by-products. Furthermore, the catalyst exhibited remarkable reusability, demonstrating consistent catalytic activity over five successive cycles without a substantial decrease in performance.