Investigation of electro-oxidation activity of Pt-CNTs/GC electrodes

The morphology and the structure character of the Pt-CNTs/GC electrode were characterized via Transmission Electron Microscopy (TEM) and the selected area electron diffraction. The electro-oxidation behavior of CO and methanol on Pt-CNTs/GC electrode were studied with cyclic voltammograms or Chrono-amperometry. Three oxidation peaks were observed for CO observed on Pt-CNTs/GC electrode. Methanol were found to be dissociated spontaneously on the electrode to produce a strong adsorbed intermediate CO. Among the three oxidation peaks, peak I is due to the briged CO adsorbing. But peaks II and III were assigned to split of the linear CO which is adsorbed on the Pt-CNTs nanocluster with different particle sizes and Pt film. The oxidation current of methanol on Pt-CNTs/GC electrode was always not increasing with the increasing of the amount of Pt loading. The result indicates that there is an optimal Pt loading for methanol oxidation. It is necessary to select the catalyst with proper pt loading when the anode of direct-methanol fuel cell was prepared.