학술논문

Comparative study of monolithic platinum and iridium as oxygen-evolving anodes during the electrolytic reduction of uranium oxide in a molten LiCl-Li2O electrolyte.
Document Type
Article
Source
Journal of Applied Electrochemistry. Apr2019, Vol. 49 Issue 4, p379-388. 10p. 1 Color Photograph, 1 Black and White Photograph, 3 Diagrams, 3 Charts, 5 Graphs.
Subject
*ELECTROLYTIC reduction
*FUSED salts
*PLATINUM
*IRIDIUM
*ANODES
Language
ISSN
0021-891X
Abstract
A series of four electrolytic reduction runs was performed in molten salt at bench scale to compare the performance characteristics of monolithic platinum and iridium as oxygen-evolving anodes, while simultaneously reducing uranium oxide to metal. In each run, 25 g of uranium oxide particulate was loaded into a permeable steel basket, which, in turn, was immersed in a pool of LiCl—1 wt% Li2O at 650 °C. Both anodes, each 3 mm in diameter, were suspended vertically in the salt pool, adjacent to the steel cathode basket. The anodes were connected in parallel to separate direct current power supplies with the uranium oxide-loaded basket as the common cathode. A cell voltage (3.1 V) was intermittently applied to the system with both power supplies operating concurrently, effecting the reduction of uranium oxide to uranium metal at the cathode basket and the simultaneous oxidation of oxygen anions in the salt to oxygen gas at each anode. Anode and cathode potentials and currents were recorded to compare the performance of platinum vis-à-vis iridium. After completing the series of runs, both anodes were removed and subjected to dimensional, chemical, and microscopic analyses. Even though the accumulated charges on each anode over the series of four runs were similar, the platinum anode exhibited up to 29% reduction in cross-sectional area compared to < 3% for the iridium anode.Graphical abstract: [ABSTRACT FROM AUTHOR]