The Electro-Oxidation of Hydrazine: A Self-Inhibiting Reaction

The electro-oxidation of hydrazine to form dinitrogen is reported over a wide range both pH and unbuffered conditions at glassy carbon electrodes. It shown that molecules are only electro-active in their unprotonated form, N2H4, whereas the protonated species N2H5+ electro-inactive. oxidation N2H4 releases four protons per molecule which diffusing away from electrode rapidly (on voltammetric time scale) protonate unreacted converting them into electro-inactive N2H5+; reaction self-inhibiting, currents flowing significantly reduced compared those expected for simple electrolytic conversion an extent reflecting buffer content solution local electrode. turn controlled partly by quantity released electrolytically. self-inhibition modeled solving relevant transport equations with coupled homogeneous chemical kinetics, utilizing Marcus-Hush electron transfer, giving predicted pKa kinetics N2H4/N2H5+ equilibrium excellent agreement experimental wave shapes.