Electrochemical Reduction of Dissolved Oxygen in Molten Amides

Oxygen is found to have a high solubility, 3.9 • 10-3M in molten acetamide at 85°C and about 2 - 10-4M in a molten amide mixture of urea-acetamide and ammonium nitrate at 25°C. The oxygen is found to undergo only a one-step, two-electron, irreversible reduction at both glassy carbon and platinum electrodes. The electrodes are used both in the stationary and in the rotating mode. The diffusion coefficients of oxygen in the range of temperatures 25–85°C are evaluated. The product of the reduction is peroxide, which is found to decompose at temperatures above 50°C, releasing more oxygen at the interface. The rate constants for the thermal decomposition of hydrogen peroxide are evaluated at different temperatures. © 1991, The Electrochemical Society, Inc. All rights reserved.