Electrochemical Reduction of Molybdenum(VI) Compounds in Molten Lithium Chloride-Potassium Chloride Eutectic

Author(s)

Branko N. Popov, University of South Carolina - ColumbiaFollow
H. A. Laitinen, University of Illinois at Urbana

Document Type

Article

Subject Area(s)

Chemical Engineering

Abstract

Molybdenum (VI) oxide reacts with molten LiCl-KCl eutectic at 450° to form MoO₂CI₂, which probably is present as an anion MoO₂Cl₄⁼, and pyromolybdate, Mo₂O₇⁼. Both of these species are electrochemically reduced to MoO₂, which can be reoxidized to MoO₂Cl₂ by current reversal. A second reduction step, observed whether MoO₃ or Mo₂O₇²⁻ is added to the melt, can be attributed to the reduction of MoO₄⁻⁻, formed as a secondary reaction product in the first step. The reduction of molybdate proceeds in two steps, the first at −0.85V and the second at −1.75V vs. the 1M Pt(II)/Pt reference electrode. The first step shows an abnormally short transition time, attributable to a slow equilibrium. The second step corresponds to a diffusion-controlled reduction with n = 0.5, yielding a product of the empirical formula Li₅Mo₂O₈.

Publication Info

Journal of the Electrochemical Society, 1973, pages 1346-1350.

Rights

© The Electrochemical Society, Inc. 1973. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in the Journal of the Electrochemical Society.

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DOI: 10.1149/1.2403259