In Situ Laser Raman Determination of Electrochemical Reactions of Y2O3-Stabilized ZrO2 and Molten Na2SO4

When used as components of advanced energy conversion systems, oxide ion conductors and molten electrolytes may react or decompose according to various mechanisms. Understanding these mechanisms is important in improving system performance. In situ laser Raman spectroscopy was used successfully to study the reactions between an oxide ion conductor and a molten salt. Changes in the Raman spectrum of molten Na₂SO₄ were observed near Y₂O₃-stabilized ZrO₂ electrodes when they were polarized anodically in the molten salt. These changes were interpreted to indicate the formation of yttrium sulfate complexes.