The electrochemical oxidation of carbon monoxide adsorbed (CO(ad)) on platinum-on-carbon electrodes was studied via a methodology in which pre-adsorbed CO was partially oxidized by applying potentio-static pulses for certain durations. The residual CO(ad) was analyzed using stripping voltammetry that involved the deconvolution of CO(ad) oxidation peaks of voltammograms to quantify the weakly and strongly bound species of CO(ad). The data obtained for various potentials and temperatures were fit to a model based on a nucleation and growth mechanism. The resulting fit produced potential- and temperature-dependent rate parameters that provided insight into the oxidation mechanism of the two CO(ad) species. Irrespective of the applied potential or temperature, the concentration of weakly bound CO(ad) species decreased exponentially with time. In contrast, the strongly bound CO(ad) species showed a gradual transition of mechanisms, from progressive nucleation at relatively low potentials to exponential decay at high potentials. (C) 2011 Elsevier Ltd. All rights reserved.