Electrical Conductivity of Lithium, Sodium, Potassium, and Quaternary Ammonium Salts in Water, Acetonitrile, Methanol, and Ethanol over a Wide Concentration Range

CO₂ can be electrochemically converted to commodity chemicals with the support of aqueous or organic electrolytes. However, aqueous electrolytes mainly lead to H₂ production due to the low solubility of CO₂ in water whereas organic electrolytes favor the formation of organic products. In addition to selectivity, fast CO₂ conversion is also important, which is significantly influenced by the conductivity of the electrolyte. However, the most studied electrolytes are aqueous and at low salt concentrations. Therefore, in this work, the electrical conductivity of 164 electrolytes was investigated in a wide concentration range and a temperature range T = (288.15 to 333.15 K) using automated conductometry. After the measurements, the results were correlated using the Casteel–Amis equation. This choice was made because many factors affecting conductivity are well documented in the literature but not universally quantifiable for all electrolytes due to isolated consideration. The wide variety of different electrolytes investigated in this study highlights the importance of considering these factors holistically rather than in isolation. Nevertheless, NaI and KSCN in methanol and (C₂H₅)₄NBF₄ in acetonitrile were identified as the three organic electrolytes with the highest conductivity. These solutions have the potential to be used as electrolytes for CO₂ reduction.