Electrochemical Behavior of Nitrate and Nitrite Ions in the Molten NaOH ‐ KOH (49 m/o) Eutectic Mixture at 250°C

The electrochemical reduction of nitrate ions in molten at 250°C is strongly dependent on the acid‐base character of the melt and on the nature of the working electrode. On silver electrodes, two well‐defined waves are observed; they are attributed to the following reactions On platinum electrodes the second step appears to be influenced by an electrode surface phenomenon. In acidic solutions, the nitrate reduction occurs through a water diffusion limited process according to following equation In acidic melts, the nitrate wave is then either split into two partial waves or completely shifted toward more anodic potentials depending on the water concentration of the melt. The nitrite ion reduction is shown to proceed as a quasireversible one‐electron process in a basic melt In acidic solutions, this reaction occurs at a potential close to the water reduction and mixed waves are observed.