ELECTROCHEMICAL CHARACTERIZATION OF THE O2-/O2(2-) SYSTEM IN MOLTEN NA2CO3+K2CO3 EUTECTIC AT 750-DEGREES-C

Experimental evidence for the reduction of superoxide and peroxide species successively by a one-electron and a two-electron step was obtained in molten Na2CO3 + K2CO3 at 750-degrees-C. The O2-/O2(2-) step was characterized by voltammetry at a gold electrode (E1/2 = -0.210 V vs. Ag+/Ag). The value of the diffusion coefficient of O2(2-) ion was determined (D = 1.5 x 10(-5) cm2/s) and the standard potential of the O2(2-)/O2- system was obtained from chronoamperometric measurements (E-degrees = -0.769 V vs. Ag+/Ag). Studies of the oxygen systems at various acidity levels have shown that CO2 does not participate in the rate-determining step.