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


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


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.