The Catalytic Performance of Metal-Oxide-Based Catalysts in the Synthesis of Glycerol Carbonate: Toward the Green Valorization of Glycerol

The rising concern over carbon dioxide (CO₂) emissions has led to increased research on its conversion into value-added chemicals. Glycerol carbonate (GC), a versatile and eco-friendly compound, can be synthesized via the catalytic carbonylation of glycerol with CO₂. This study investigates the catalytic performance of three novel mixed metal oxide catalysts, Ti-Al-Mg, Ti-Cr-Mg, and Ti-Fe-Mg, synthesized via co-precipitation. The catalysts were characterized using XRD, SEM, XPS, CO₂-TPD, FTIR, TGA-DTG, and nitrogen adsorption–desorption isotherms. Among the tested systems, Ti-Al-Mg demonstrated the highest surface area, optimal porosity, and a balanced acid–base profile, resulting in superior catalytic activity. Under optimized conditions (175 °C, 10 bar CO₂, 4 h), Ti-Al-Mg achieved a maximum GC yield of 36.1%, outperforming Ti-Cr-Mg and Ti-Fe-Mg. The improved performance was attributed to the synergistic effects of its physicochemical properties, including high magnesium content and lower CO₂ binding energy, which favored CO₂ activation and glycerol conversion while minimizing side reactions. These findings highlight the potential of tailored mixed metal oxide systems for efficient CO₂ immobilization and sustainable glycerol valorization.