High yield room temperature conversion of carbon dioxide into cyclic carbonates catalyzed by mixed metal oxide (CuO-ZnO) nano-flakes/micro-flakes (Cozi-nmf)

Capturing and converting carbon dioxide (CO2) into useful organic molecules and polymers is the best way of alleviating excessive release of it from industrial sources to the environment. Cyclic carbonate synthesis by cycloaddition from CO2 and epoxides through a catalytic process is a 100% atom economic reaction established five decades ago. Despite the availability of many efficient catalytic systems, there are shortcomings in either tedious preparatory procedure of catalyst, separation problem associated with homogeneous catalysis, or the requirement of pure CO2. In this work, we report the catalytic system based on copper and zinc mixed metal oxides (CuO-ZnO) nano-flakes/micro-flakes (Cozi-nmf) for cycloaddition of CO2 with various epoxides at room temperature under solvent-free conditions. The novel recyclable heterogeneous catalyst was prepared via a simple procedure successfully at room temperature by grinding process. The synthesis of both catalyst and cyclic carbonates described here is greener and used inexpensive source materials to produce them. The yields of the synthesized cyclic carbonates were more than 95%, except for many reactions. The high efficiency of Cozi-nmf as a catalyst is explained based on the availability of the bare catalyst surface, which promoted the hindrance free movement of electrons and adsorption of substrate effectively.

Automated summary

A method for cycloaddition of CO2 with various epoxides using CuO-ZnO catalyst at room temperature without solvent has been discovered, resulting in high yields of synthesized cyclic carbonates and cost savings.