Oxidation of Nickel in AlCl3-1-Butylpyridinium Chloride at Ambient Temperature

We have studied in detail the electrochemical reaction of nickel in several kinds of molar ratio-controlled molten salts consisting of AlCl3 and 1-butylpyridinium chloride (BPC) at 40 degrees C. We observed NiCl2 as an oxidation product from nickel on the surface of the electrode in slightly acidic AlCl3/BPC salts with molar ratios of 1.05/1.0 and 1.1/1.0. However, in strongly acidic salt with the ratio of 1.5/1.0, NiCl2 deposits on the electrode less than when in the above salts, and no NiCl2 is observed in basic and neutral salts with the ratio of 1.0/1.0 or less AlCl3 content. This suggests that [NiCl4](2-) ions form as the oxidation of nickel in such neutral and basic AlCl3/BPC salts. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.