Experimental and simulation study of the electrode reaction mechanism of La3+ in LiCl-KCl eutectic molten salt

C. P. Fabian (1) , Vittorio Luca (2) , Pierre Chamelot (3) , Laurent Massot (3) , Concepción Caravaca (4) , Gregory R. Lumpkin (1)

1 Institute of materials engineering (Blackburn, Australia)
2 CNEA - Comisión Nacional de Energía Atómica [ARGENTINA]
3 LGC - Laboratoire de Génie Chimique
4 CIEMAT - Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas

Nuclear energy increasingly represents an important option for generating largely clean CO2-free electricity. The present investigation addressed the electrochemical reduction of La3+, a rare earth element, in LiCl - KCl eutectic molten salt in the temperature range 450-550°C using transient techniques such as cyclic voltammetry (CV) and square-wave voltammetry (SWV). Simulation of the CV data suggested a reaction mechanism in which lanthanum reduction occurred in a single three-electron step (La3+ + 3e− → La°). The rate constant, k° was determined to be 5.7 x 10−3, 14.6 x 10−3 and 31.7 x 10−3 cm/s and the Matsuda et al.1 dimensionless parameter Ʌ was 0.82, 1.52 and 2.89 for temperatures of 450, 500 and 550°C, respectively and therefore it was concluded that the was process quasi reversible.

Mots clés: La3+ ion; Cyclic voltammetry (CV); Square-wave voltammetry (SWV); Electrochemical reduction

Domaines: Génie chimique; Radiochimie; Analyse de données, Statistiques et Probabilités [physics.data-an]

C. P. Fabian, Vittorio Luca, Pierre Chamelot, Laurent Massot, Concepción Caravaca, et al.. Experimental and simulation study of the electrode reaction mechanism of La3+ in LiCl-KCl eutectic molten salt. Journal of The Electrochemical Society, 2012, vol.159, pp. 63-67. ⟨10.1149/2.057204jes⟩. ⟨hal-00861174⟩