| Résumé | The development of carbon dioxide electrochemical reduction (CO₂ER) has mainly focused on aqueous electrolytes. However, the low solubility of apolar CO₂ in polar water negatively impacts the electrochemical process, especially mass transport. Organic-based electrolytes, such as methanol, acetonitrile, and dimethylformamide, have been explored as an alternative due to increased CO₂ solubility. Yet, insights into other organic electrolytes are scarce. Dinitrile solvents have decreased polarity in comparison to the mononitrile solvent acetonitrile and thus can potentially further increase CO₂ solubility and advance the reaction’s performance. Herein, the novelty of dinitrile-based electrolytes for the application of CO₂ER is explored. Acetonitrile, adiponitrile, and sebaconitrile were used to study the effects of a secondary nitrile group addition and the length of the aliphatic, nonpolar chain on salt solubility, electrolyte conductivity, and CO₂ solubility. Electrochemical effects were evaluated through cyclic voltammetry (CV) and chronoamperometry (CA) measurements with copper (Cu) and copper oxide (CuO) commercial nanoparticle catalysts. DFT calculations were employed to further explore the CO₂ interactions with the selected solvents. Finally, it was found that tuning the polarity of the nitrile solvent results in a profound effect on the physiochemical properties of the electrolyte solutions, markedly CO₂ solubility and the CO₂ER. |
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