Investigations of the Electrodeposition of Aluminum and Chromium from an Acidic Chloroaluminate Molten Salt

摘要

The electrochemical reduction of chromium (II) in acidic AlCl_3:EMIC (1-ethyl-3-methylimidazolium chloride) room temperature molten salt results in codeposition of aluminum and chromium. Two reduction peaks are observed in staircase cyclic voltammetry, with the first peak significantly smaller than the second. Constant potential deposition in the region of the first reduction peak results in the deposition of chromium rich BCC chromium-aluminum alloys. Constant potential deposition in the region of second peak results in the formation of aluminum rich FCC chromium-aluminum alloys. Evaluation of the chronoamperometric transient behavior on platinum during electrodeposition of the first peak shows that the codeposition of chromium and aluminum proceeds via three-dimensional progressive nucleation with diffusion controlled growth.