Abstract
Pt/CeO~2~/CNT catalysts were prepared by adsorbing Pt nanoparticles on the supports of CNTs coated with CeO~2~. The electrocatalytic performances in respect to the electrooxidation of chemisorbed CO were tested using potential step and stripping voltammetry methods under variable sweep rate and temperature conditions. At 10βmVβs^β1^, the CO stripping voltammogram exhibited the peak splitting phenomenon. The oxidation charge and the peak potential of the two voltammetric peaks changed regularly with the number of Pt and CeO~2~ neighbours, the sweep rate, and the temperature. We considered that the low potential peak originated from the reaction of CO~ads~ with hydroxyl groups on CeO~2~ adjacent to Pt sites, while the high potential peak came from the reaction of CO~ads~ with hydroxyl groups produced on pure Pt. Furthermore, the experimental results of the peak potential against the logarithm of the sweep rate and the logarithm of the current maximum time against the step potential were plotted and intersecting lines with different slopes in high and low potential regions in the plot were observed. The lines intersected at lower potentials on the Pt/CeO~2~/CNT electrode than on the Pt/CNT electrode, which was attributed to the contribution of hydroxyl groups on CeO~2~.