Electrochemical Reduction of Chromate in the Presence of Nickel Chloride 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

Chronopotentiometry of chromate in the presence of NiCl₂ in molten LiCl-KCl eutectic reveals a diffusion controlled, three electron reduction step. In the presence of excess NiCl₂, chromate is reduced at −0.35V vs. Pt(II)/Pt reference electrode and the electroactive species responsible for the chrono-potentiometric wave is estimated to have a diffusion coefficient of 1.06 · 10⁻⁵ cm² sec⁻¹ at 450°C. The stoichiometry of the reduction product depends mainly on the temperature at which the deposit is formed. At 500°C the deposit approaches the composition LiNi₂CrO₄. X-ray powder diffraction shows the deposit to be a single compound with a face centered cubic lattice. The length of the unit cell edge is estimated to be 4.14Å. At 1400°C a weight loss of the deposit is observed. X-ray powder diffraction shows the presence of two phases, which are identified as NiO and NiCr₂O₄ The weight loss is attributed to volatization of Li₂O.

Publication Info

Journal of the Electrochemical Society, 1970, pages 482-484.

Rights

© The Electrochemical Society, Inc. 1970. 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.

http://www.electrochem.org/

DOI: 10.1149/1.2407546