ELECTRODISSOLUTION AND ELECTRODEPOSITION OF LEAD IN AN ACIDIC ROOM-TEMPERATURE CHLOROALUMINATE MOLTEN-SALT

The electrodissolution of a lead rotating disk electrode and the electrodeposition and stripping of lead at a glassy carbon electrode were studied in the 66.7-33.3 mole percent (m/o) aluminum chloride-1-methyl-3-ethylimidazolium chloride molten salt at 40-degrees-C. The electrodissolution of lead to produce lead(II) is a quasireversible process with an anodic transfer coefficient and a formal heterogeneous rate constant of 0.33 +/- 0.04 and (3.8 +/- 0.4) X 10(-9) mol s-1 cm-2, respectively. The electrodeposition of lead on glassy carbon from solutions of PbCl2 exhibits progressive three-dimensional nucleation with diffusion-controlled growth of the nuclei. The stripping of lead from this electrode proceeds with 100% efficiency. The formal potential of the Pb2+/Pb couple is 0.400 +/- 0.004 V, and the diffusion coefficient and Stokes-Einstein product for lead(II) are 9.00 X 10(-7) cm2 s-1 and (2.7 +/- 0.1) X 10(-10) g cm s-2 K-1.