Direct Electrosynthesis of Glycolate From Carbon Dioxide.

Electrocatalytic carbon dioxide reduction reaction (CO2RR) is an attractive and green technology that can convert renewable electricity into high-energy-density fuel, which is of great significance for alleviating the dual pressures of energy and environmental concern. Although the electrosynthesis of some C2 products (e.g., ethylene, acetate, and ethanol) has achieved certain success, the generation of glycolate is still beyond the scope of existing electrocatalytic technologies. Here, we report the electrochemical reaction of direct conversion of CO2 to glycolate in aqueous media under ambient conditions using unsaturated Cu sites as the catalyst, with a production rate of glycolate up to 305 ± 24 mmol h-1 g-1. Further mechanism studies have shown that the key to glycolate generation is the formation and timely desorption of the *OHCCHO intermediate after C-C coupling, followed by a disproportionation reaction with base to generate the product. This work provides a successful case for the sustainable synthesis of glycolic acid from CO2 in aqueous media, which represents a new product from electrocatalytic CO2RR.