Chronovoltamperometry at the platinum in the KF–NaF–AlF3–Al2O3 melt

A.V. Suzdaltsev, A.P. Khramov, O.V. Limanovskaya, V.N. Nekrasov, Yu.P. Zaikov

KEYWORDS:

oxide-fluoride melt, platinum, chronovoltammetry, electrochemical and chemical stages.

ABSTRACT:

Some peculiarities of the mechanism and kinetics of non steady anode process at the platinum in the KF–NaF–AlF3–Al2O3 melt in dependence on temperature (750,780°C), potential sweep rate (0.01-10V/s), and atmosphere (argon, oxygen) in closed experimental cell were investigated using chronovoltammetry technique. A wave corresponding to evolution of molecular oxygen and a peak preceding it, possibly, of the electrochemical oxidation of platinum with formation of PtxO were specified in the volt-amper dependences. The system of algebraic equations, describing the volt-amper dependence of quazistationary   (0.01 V/sec) discharge of oxide-fluoride anions at the platinum anode, considering electrochemical formation and chemical decomposition of platinum oxide compound PtxO . The comparative analysis of experimental and calculated volt-amper dependences was carried out.