Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The Electrodeposition of Al-Cu Alloys from Room-Temperature Chloroaluminate Electrolytes



Gery R. Stafford, V D. Jovic, Thomas P. Moffat


The electrodeposition of Cu-Al alloys, as well as the underpotential deposition (UPD) of Al onto Cu(lll), were investigated in acidic aluminum chloride/1-methyl-3-ethylimidazolium chloride ambient temperature molten salt. It was shown that it is possible to produce Cu-Al alloy deposits at potentials positive of that corresponding to the electrodeposition of bulk Al. The onset of Al codeposition was found to occur at approximately 0.30 V versus the Al(III)/Al couple, and the Cu-Al alloy composition was found to be independent of the Cu(I) concentration, reaching a maximum value of 43% atomic fraction Al at 0 V. Alloy deposition potentials based on free energy calculations are in good agreement with those observed experimentally for Zn-Al, Cu-Al, Co-Al, and Fe-Al deposited at room temperature and Ni-AL deposited at 150 C from an aluminum chloride/sodium chloride melt. Cyclic voltammograms recorded on Cu(111)clearly indicate that UPD of Al commences at about 0.30 V vs. Al and is characterized by two distinct surface processes. In-situ scanning tunneling microscopy (STM) examination indicates that an ordered ad-layer appears on the Cu(111) surface at potentials positive of the first UPD wave. A possible model representing this structure corresponds to a layer of tetrachloroaluminate ions, oxidatively adsorbed on the Cu(111) surface, with the face of the tetrahedra adjacent to the copper surface.
International Symposium on Molten Salts
# 41


Cu-Al alloys, electrodeposition, free energy, room-temperature molten salt, UPD of Al


Stafford, G. , Jovic, V. and Moffat, T. (1999), The Electrodeposition of Al-Cu Alloys from Room-Temperature Chloroaluminate Electrolytes, International Symposium on Molten Salts (Accessed April 22, 2024)
Created October 1, 1999, Updated February 17, 2017