Underpotential Deposition of Al-Ce Alloys at an Al electrode from LiCl-KCl-CeCl3 Melts

Abstract:

Electrochemical behavior of Ce(III) and underpotential deposition of Al-Ce alloys were investigated at an Al active electrode in LiCl-KCl-CeCl3 melts. Compared with the cyclic voltammetry curves on a Mo electrode, the redox potential of Ce(III)/Ce at an Al electrode was more positive; there were two new plateaus between the deposition plateau of Al and Ce metal by circuit chronopotentiometry, which means forming two kinds of intermetallic compound. These results showed Ce(III) forming intermetallic compound due to underpotential deposition by electrochemical theory. Furthermore, these were confirmed by Al-Ce alloys, which were obtained at Al active electrode in LiCl-KCl-CeCl3 melts after potentiostatic deposition under the same condition. The formation of AlCe and AlCe3 were illuminated by X-ray diffraction (XRD). The analysis of scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) showed that cerium exists at the surface of Al electrode to form a layer, which was about 28?m evenly coated the Al electrode.

Key words:LiCl-KCl melts; Underpotential Deposition; Al electrode; Al-Ce alloy