Electrochemical reduction of niobium ions in molten LiF-NaF

The mechanism of the electrochemical reduction of niobium ions in molten LiF-NaF (11 mol) has been studied in detail at 750 and 800° C by the use of cyclic voltametry, chronoamperometry and chronopotentiometry. In the solution of niobium ions in LiF-NaF, it is concluded that the mechanism for the electrochemical reduction of fluoroniobate is: Nb^v+eNb^IV Nb^IV+4eNb⁰ at potentials of about –0.06 and –0.17 V, respectively (referred to the reliable Ni/NiF₂ (1 mol%) electrode [1]. The electrochemical reaction Nb^IV+4eNb⁰ is a (quasi)reversible and diffusion-controlled process.The conclusion has also been confirmed by analysis of the cathodic product obtained at constant potential with a scanning electron microscope.