A reversible oxygen electrode in an equimolar KNO3NaNO3 melt saturated with sodium peroxide—II. A voltammetric study

✍ Scribed by J.M. De Jong; G.H.J. Broers

• Book ID: 103065099
• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 672 KB
• Volume: 21
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(76)85062-1

✦ Synopsis

Ahatraet

-Voltammetric experiments, using rotating graphite and platinum electrodes have been carried out in molten KNOs-NaNOs eutectic containing superoxide ions or saturated with sodium peroxide. The experimental curves are compared with those theoretically predicted on the basis of the assumed simultaneous reactions: 02 + e-* o;, (a) 0; + e-+ O:-. (b) The experiments in dilute superoxide solutions confirm the results of Zambonin et al. A value for the superoxide disproportionation constant has been obtained from the difference of the half-wave potentials, viz X, = 8.1 x 10m2 kg atm mole-' at SO3 K. The peroxide ions produced according to equation (b) cause a NazOa precipitate on the electrode, even in unsaturated melts. From the experimental data the oxygen, superoxide and peroxide diffusion coefficients have been calculated to be: Do, = 3.8 x 10-4cm2 s-l, Do5 = 4.4 x 10-6cm2s-' and 00:~ = 6.6 x 10-6cm2s-L, respectively.