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

Abstract

The morphology and structure of Pt-CNTs/GC electrodes were characterized via Transmission Electron Microscopy (TEM) and selected area electron diffraction. The electro-oxidation behavior of CO and methanol on Pt-CNTs/GC electrodes were studied with cyclic voltommograms or chronoamperometry. Three oxidation peaks were observed for CO absorbed on Pt-CNTs/GC electrodes. Methanol was found to be dissociated spontaneously on the electrode to produce a strong absorbed intermediate CO. Among the three oxidation peaks, peak I was presumed to be due to the bridged CO absorption while peaks II and III were attributed to the split in the linear CO which is absorbed on the Pt-CNTs/GC nanocluster with different particle size and Pt film. The oxidation current of methanol on the Pt-CNTs/GC electrode did not always increase with the increase in 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 a direct-methanol fuel cell is prepared.

Keywords

platinum / carbon nanotube / methanol / carbon monoxide