Underpotential deposition (UPD) of Cd on polycrystalline Au, Au(poly), has been found to catalyze the reduction of selenate in 0.1 M HClO4 to yield, following stripping of the Cd-UPD layer, elemental Se. Under certain conditions, the rates of this process, as measured by the charge under the peak associated with Se oxidation, were found to be nearly constant, with values which increased with the applied overpotential. (C) The Author(s) 2019. Published by ECS.