Previously, we reported an increase in the rate of deposition of Re when ions of Ni, Fe, or Co were added to the plating bath. The mechanism proposed was that the divalent ions were reduced to the metallic form, and the resulting atoms reduced the ReO4- ion chemically to Re-0. Here, the validity of this mechanism was tested and found applicable by studying the chemical reduction at open circuit of ReO4-by iron-group metal foils or thin films. The coatings formed were studied by X-ray photoelectron spectroscopy, and the reduction of the ReO4- ion was proven. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3489532] All rights reserved.