Redox behaviour of cerium (III) in LiF–CaF2 eutectic melt

Electrochemical redox behaviour of Ce (III) ion in LiF–CaF2 eutectic was studied at 1093 K using tungsten (inert) and nickel (reactive) as working electrodes and platinum as quasi-reference electrode by various electrochemical transient techniques viz. cyclic voltammetry (CV), square-wave voltammetry (SQWV) and chronopotentiometry (CP). It was deduced that reduction of Ce (III) to Ce metal occurs by a single step, three-electron transfer. Diffusion coefficient (DCe(III)) of Ce (III) ion was determined from CV, semi-integral analysis and CP and the values obtained were 2.2 × 10−5, 5.4 × 10−5 and 3.0 × 10−5 cm2 s−1, respectively. Electrochemical studies in the presence of Ni electrode showed the formation of the inter-metallic compounds CeNi5 and Ce2Ni7, which were characterized by powder X-ray diffraction and SEM-EDAX analysis.

► Reduction of Ce (III) to Ce (0) involves single step, three electron transfer.
► Ce (0) was observed on the W electrode.
► Ce–Ni intermetallics were observed on the Ni electrode.
► Deposits were analyzed by electrochemical, SEM-EDAX and XRD methods.