The Role of Adsorption in the Electrocatalysis of Hydrazine on Platinum Electrodes

Abstract

Hydrazine oxidation on platinum single-crystal electrodes has been studied in acidic solution containing different electrolytes. It will be shown that the hydrazinium cation is adsorbed on platinum through an anodic reaction. Moreover, in the presence of chloride, this adsorption process is favored owing to the formation of an ionic pair with adsorbed chloride. In spite of the enhanced adsorption of hydrazine species in the presence of chloride, higher overpotentials are measured in these media, which reveals that the oxidation of hydrazine not only requires adsorption, but also that the adsorption mode of the species facilitates the formation of the transition state to yield the final product.