Electrolyte-Guided Design of Electroreductive CO Coupling on Copper Surfaces

Engineering the interfacial distribution of electrolytic ions can aid in modulating the electrocatalyst performance and efficiency. Using a hybrid quantum-classical modeling approach, we describe how predictive tuning of the solution microenvironment on copper can enhance the efficiency of CO2 reduction (CO2R) to C-2 products. We elucidate how competing electrolyte constituents in mixed electrolyte solutions stimulate restructuring of the electrochemical double layer (EDL) and stabilize the OCCO* dimer (* denotes surface adsorbed), with predictions validated in flow reactors using copper gas diffusion electrodes (Cu-GDEs). Our findings highlight how molecular-scale electrolyte engineering with informed models of the EDL can be leveraged to tailor CO2R activity and selectivity toward C-2 products.

Automated summary

Manipulating the interfacial distribution of electrolytic ions can enhance the efficiency and selectivity of CO2 reduction to C-2 products. This can be achieved through predictive tuning of the solution microenvironment on copper and by stimulating restructuring of the electrochemical double layer using competing electrolyte constituents. Our findings demonstrate the potential of molecular-scale electrolyte engineering to tailor CO2R activity and selectivity.