Developing the Glycerol Carbonylation Process Using Photocatalysis and 2-Cyanopyridine as a Water-Reducing Agent

This study investigates the direct carbonylation of glycerol using a composite photocatalyst (TiO2 loaded with cellulose) and 2-cyanopyridine as a water-reducing agent. In this research, the performance of the photocatalytic system was evaluated under different conditions, including various concentrations of 2-cyanopyridine, glycerol, and catalyst dosage, as well as changing the molar ratios of CO2 to glycerol and reaction times. The optimal conditions for achieving high glycerol conversion and GlyCO3 performance were determined, resulting in a glycerol conversion of 92.43% and a yield of 91.12% towards glycerol carbonate under these conditions. Increasing the concentration of 2-cyanopyridine up to 30 mmol enhanced GlyCO3 production. However, excessive amounts led to decreased yields due to catalyst site blockage. The influence of the CO2 to glycerol molar ratio on GlyCO3 yield was marginal within a certain concentration range, indicating a non-limiting CO2 supply. Catalyst loading significantly affected product yield, with higher concentrations promoting greater GlyCO3 formation. However, catalyst reusability tests revealed a decline in activity after recycling, attributed to drying-induced deactivation. These findings provide valuable insights into optimizing the cellulose-TiO2 photocatalyst for efficient glycerol carbonylation, contributing to the advancement of sustainable chemical processes.