ELECTRO-OXIDATION OF HYDRAZINE ON MERCURY SILVER AND GOLD ELECTRODES IN ALKALINE SOLUTIONS

Polarisation curves on the dropping mercury electrode were obtained varying concentration, ionic strength and pH on the solution, and on rotating silver and gold disc electrodes varying concentration and pH of the solution, and speed of rotation of the electrode. The value of ∂E/∂ log[i/Id-i)] is approximately 0.06 V for the mercury and gold electrodes and 0.12 V for the silver electrode. The value of ∂E 1 2/∂pH is -0.06 V for the mercury electrode and -0.05±0.01 V for the gold electrode. Polarisation curves on the silver electrode seem to be independent of pH. The half-wave potential of the oxidation of hydrazine on the mercury electrode is independent of the potential difference across the diffuse double layer, φ{symbol}2. The process at the silver electrode is direct discharge of the hydrazine molecule. The rate-controlling process in the oxidation at mercury and gold electrodes is either a two-electron electrode reaction with participation of hydroxide ions or a chemical volume or surface reaction of the product of a one-electron reversible oxidation. © 1969.