Coupling Electrocatalytic CO 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 , but the coupling of these two processes is yet to be considered. Merging electrocatalytic reduction of CO to CO with thermocatalytic use of CO would expand the range of the chemicals produced from CO . This work describes the development of a system coupling a high-pressure CO 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 %. Although the production of monomers and polymers from CO is currently limited to organic carbonates, this strategy opens up the access to lactones from CO , for the formation of polyesters.