K. Bouzek et I. Rousar, CURRENT EFFICIENCY DURING ANODIC-DISSOLUTION OF IRON TO FERRATE(VI) IN CONCENTRATED ALKALI HYDROXIDE SOLUTIONS, Journal of Applied Electrochemistry, 23(12), 1993, pp. 1317-1322
The dependence of the current efficiency for oxidation of an iron anod
e to ferrate(VI) ions in 14 M NaOH was measured in the region of free
convection. The highest current yield of 40% was obtained at a current
density of 2.1 mA cm-2 and temperature of 30-degrees-C. The iron anod
e was activated by cathodic prepolarization. The iron concentration in
low oxidation states in solution was determined as 0.13 +/- 0.1 and 0
.29 +/- 0.25 g Fe dm-3 at 20 and 30-degrees-C, respectively. The stead
y state anodic polarization curves of iron in the transpassive potenti
al region are shifted to lower potential values with increasing NaOH c
oncentration from 11 to 17 m. At 40-degrees-C all the curves show a li
miting current density around 660 mV vs Hg/HgO. namely 9 and 23 mA cm-
2 at NaOH concentrations of 11 and 17 M, respectively.