ANODIC PROCESSES OCCURRING DURING PALLADIUM DISSOLUTION IN NACL-KCL-CSCL EUTECTIC MELTS

The anodic processes occurring during palladium dissolution in NaCl-KC l-CsCl eutectic melts at 500-700-degrees-C were investigated galvanost atically. The anodic current yields are close to 100% up to 13 A/cm2 w hen calculated with the assumption of a two-electron reaction. The pol arization curves for palladium anodes in the base melt exhibit a wave at low current densities which precedes palladium dissolution and is d ue to the electrooxidation of oxy compounds present as impurities. Dur ing electrochemical oxidation of palladium-ion-containing melts at a g lassy-carbon anode, the polarization curves exhibit a wave at potentia ls of -0. 7 to -0.6 V which is due to the dissolution of metallic pall adium formed by a reaction between palladium ions and the oxy compound s present as impurities when the glassy carbon is kept in the melt al open circuit. For the oxygen ion concentration in the melts, values of about 10.2 mol% were estimated.