Electrochemistry of Fused Salts.

摘要

The mechanism of electroreduction of chromate ion in LiCl-KCl melts is discussed. The chromium(V) species CrO4(3-), was isolated as its lithium salt which is sparingly soluble in the melt. This compound is regarded as an intermediate in the cathodic reduction of chromate. Its chemical reactions with divalent metal ions can be related to the formation of complex, nonstoichiometric double salts of chromium(III). Traces of moisture in LiCl-KCl melts were found to exert profound influences upon certain electrode processes. Molybdate in the presence of zinc chloride in LiCl-KCl melts gives Li2ZnMo2O8, which can be regarded as a compound of two MoO4(3-) ions packed into a lattice with Li(+) and Zn(2+). Antimony doped tin oxide is a useful anode material in LiCl-KCl melts. Eu(III)/Eu(II) and iron(III)/iron(II) show essentially reversible behavior whereas copper(II)-copper(I) and Pt(IV)/Pt(II) show abnormalities. Zirconia based solid electrolytes of various compositions have been tested as membranes for electrodes specific to oxide ions. Y2O3-stabilized zirconia proved to be the best electrolyte, responding almost in accordance with theory to oxide ion activity.