The Electrochemical Reduction of Molten Perchlorate and Chlorate Salts

Abstract

The electrochemical reduction of molten occurs much more readily on nickel electrodes than on platinum electrodes. This is likely related to the catalytic effect of the nickel oxide that forms on the electrode surface in oxidizing electrolytes. Both the thermal decomposition and the electrochemical reduction of molten chlorates and perchlorates require the rupture of Cl‒O bonds. Such bond breaking processes appear to be catalyzed by the positive field of nearby cations and by p‐type oxides. Cyclic voltammetric studies show that is more readily reduced than and that both form insoluble oxides as products. Potential vs. temperature measurements at a constant current density show nearly linear behavior between about 260°–380°C for the electrochemical reduction of on nickel. Kinetic parameters calculated from these measurements yield 0.2 for the transfer coefficient, 15 kcal/mole for the activation energy, and for the exchange current density at 350°C. The transfer of the first electron accompanied by breakage of the Cl‒O bond is postulated to be the slow step in the reduction reaction.