Electrochemical reduction of solutions of ReF6 in fused LiF–NaF–KF eutectic mixture

Electrolyte was prepared by introducing gaseous ReF6 into the molten LiF–NaF–KF eutectic at 600 °C. The electrochemical properties of the solutions were studied by voltammetric techniques. The reduction of ReF82− to Re occurred via a single irreversible step with diffusion controlled mass transfer. The diffusion coefficient of ReF82− was 8 × 10−10 m2 s−1 and the cathodic transfer coefficient was 0.13. Well-crystallized pure rhenium layers, up to 50 μm thick, were obtained on W, Ag, graphite and vitreous carbon substrates and were examined by SEM and X-ray diffraction techniques.