Catalytic Performance of Li/Mg Composites for the Synthesis of Glycerol Carbonate from Glycerol and Dimethyl Carbonate.

A series of Li/Mg composites were synthesized by the coprecipitation method using magnesium and lithium nitrates, and then used for the synthesis of glycerol carbonate (GC) from glycerol and dimethyl carbonate (DMC). The experimental results indicated that Li/Mg composites were prospective catalysts for GC synthesis. 92.05% glycerol conversion and 90.61% GC yield were obtained after reacting at 80 °C for 2 h in the presence of Li/Mg composites. The structure and properties of Li/Mg composites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Brunauer-Emmett-Teller (BET), and CO-temperature-programmed desorption (TPD) techniques. It was inferred that the basic strength and basicity of Li/Mg composites were improved with increase in Li content. It was concluded that LiCO was the main reactive species. A too-strong basic strength of Li/Mg composites could facilitate the glycerol conversion but impair GC selectivity.