Study of Am electrodeposition from AmCl₃-LiCl-KCl Molten Salt

In this work, the electrodeposition reaction of Am in AmCl 3 -LiCl-KCl molten salt was studied using voltammetry and chronoamperometry. Electrodeposition of Am was shown to proceed via a two <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>−</mml:mo> </mml:math> step reaction scheme, involving the one-electron transfer reduction of Am 3+ to Am 2+ , followed by the two-electron transfer reduction of intermediate Am 2+ to Am 0 . A low Coulombic efficiency of Am deposition was measured despite the Am deposition occurring within the thermodynamic stability window of the supporting LiCl-KCl electrolyte. We hypothesize that the low efficiency is due to out-diffusion of the intermediate Am 2+ species away from the electrode surface. Experimental observations provide evidence of a kinetically <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>−</mml:mo> </mml:math> limited electrodeposition reaction, which allows for the loss of intermediate Am 2+ via diffusion leading to Am deposition inefficiency.