Electrochemical properties of noble metal anodes for electrolytic reduction of uranium oxide

Abstract

Noble metals (Rh, Pd, Ir, and Au) were investigated as O2-evolving anodes for electrolytic reduction of UO2 in LiCl–Li2O molten salt to replace Pt anodes, which are gradually consumed owing to Li2PtO3 layer formation. Anodic behaviors of these metals were examined by cyclic voltammetry. Au only showed O2 evolution in a moderate potential range without side reactions, suggesting better electrochemical stability relative to Pt anodes. With Au anodes, UO2 was electrochemically reduced to metallic U. No oxide layer was observed on the surface after the reduction. However, local dissolution remains a potential issue from a stability viewpoint.