Application of Fluorescent Carbon Dots as Catalysts for the Ring-Opening Reaction of Epoxides

Considering the increased anthropogenic emissions of CO₂ into the atmosphere, it is important to develop economic incentives for the use of CO₂ capture methodologies. The conversion of CO₂ into heterocyclic carbonates shows significant potential. However, there is a need for suitable organocatalysts to reach the required efficiency for these reactions. Given this, there has been an increasing focus on the development of organocatalytic systems consisting of a nucleophile and a hydrogen bond donor (HBD) so that CO₂ conversion can occur in ambient conditions. In this work, we evaluated the potential of fluorescent carbon dots (CDs) as catalytic HBDs in the ring-opening reaction of epoxides, which is typically the rate-limiting step of CO₂ conversion reactions into heterocyclic carbonates. The obtained results demonstrated that the CDs had a relevant catalytic effect on the studied model reaction, with a rate constant of 0.2361 ± 0.008 h^-1, a percentage of reactant conversion of 70.8%, and a rate constant enhancement of 32.2%. These results were better than the studied alternative molecular HBDs. Thus, this study demonstrated that CDs have the potential to be used as HBDs and employed in organocatalyzed CO₂ conversion into value-added products.