Electrode reactions of electrochemically generated selenium species in basic AlCl3-NaCl melts

The electrochemical reactions of selenium species in basic AlCl3-NaCl melts were studied using various voltammetric techniques. The electrochemical measurements were carried out in a basic melt containing different oxidation states of selenium, which were prepared by electrochemically oxidizing elemental selenium. The results obtained in this study present a new interpretation for the reaction mechanism of the oxidation of elemental selenium to tetravalent selenium, which proceeds via at least four electrochemical steps involving the following intermediates, Se-8(2+), Se-4(2+), Se-2(2+) and Se2+. It is also confirmed that the reaction sequence is in good agreement with the results obtained by the thermodynamic analysis of emf of a Na/SeCl4 cell in our previous study.