Coupling electrocatalytic CO2 reduction with thermocatalysis enables the formation of a lactone monomer

Carbonylation reactions that generate high-value chemical feedstocks are integral to the formation of many industrially significant compounds. However, these processes require the use of CO, which is invariably derived from fossil-fuel-reforming reactions. CO may also be generated through the electroreduction of CO 2 , but the coupling of these two processes is yet to be considered. Merging electrocatalytic reduction of CO 2 to CO with thermocatalytic use of CO would expand the range of the chemicals produced from CO 2 . This work describes for the first time the development of a system coupling a high-pressure CO 2 electrolytic cell containing a bimetallic ZnAg catalyst at the cathode for production of CO with a reactor with a faradaic efficiency of >90 % where high pressure CO is used for carbonylating propylene oxide into β -butyrolactone by thermal catalysis, the latter step having a reaction yield above 80%. While the production of monomers and polymers from CO 2 is currently limited to organic carbonates, this strategy opens up the access to lactones from CO 2 , for the formation of polyesters.