Understanding Carbon Dioxide Electrochemical Reduction in Aprotic Solvents

Carbon dioxide (CO2) conversion is vital because it provides a pathway to efficiently valorize CO2 and incentivize CO2 capture. Electrocatalytic CO2 conversion is of great interest because it is scalable and can be done at ambient temperature and pressure. However, these reactions are typically performed in water which suffers from undesired hydrogen evolution reaction (HER) from water breakdown. Furthermore, catalyst selection is often determined by the ability of the catalyst to favor CO2RR over HER. Aprotic nonaqueous electrolytes can suppress HER and enable a wider range of catalysts for CO2RR. Here, we study the influence of aprotic electrolyte solvent on CO2RR. Firstly, we probe the ability of aprotic electrolytes to enable earth-abundant catalysts for CO2RR to CO. Secondly, we understand the influence of dissolved water and water solvation in aprotic electrolytes and the ability of aprotic electrolytes to enhance or suppress HER. Our work pushes the field in the understanding of electrolyte solvent and water effects for electrochemical transformations such as CO2RR and HER