| Proton exchange membrane fuel cell (PEMFC) is one of the most promising cells used for transportation and portable power sources for it has prominent merits such as high efficiency, cleanness and et al. However, the intolerable cost and poor catalysis of the catalyst Pt currently used in PEMFC, together with other technical problems, block PEMFC from commercialization.At present, most of work has been devoted to increase the utilization of platinum (Pt) catalysts and thus to lower the catalyst usage. CNTs as a new form of carbon, have received researchers'attention due to their unique structural, electronic and mechanical properties. The use of CNTs as alternative supports for preparation of catalysts for low-temperature fuel cells has naturally stimulated significant interest among researchers. In recent years there has been a progress in the understanding of that the catalyst-support interaction plays a fundamental role in the performance of catalyst.In this paper, CNTs were functionalized by mix-acid oxidation. The oxygen-containing functional groups would be introduced on the CNT defect sites. The Pt/FMCNTs were prepared by spontaneous reduction of PtCl62- ion on functionalized CNTs defect sites from H2PtCl6 aqueous solution. XRD analysis and SEM images show that Pt nanoparticles are highly dispersed on the surface of chemically and electrochemically functionlized CNTs electrode, with Pt particle size of 4 nm. The electrochemical surface area and the Pt utilization are enhanced in Pt/FMCNTs electrode, and the electrocatalytic activity for oxygen reduction is visibly higher than the commercial Johnson matthey 40wt% Pt/C electrode,which was attributed to the specific structure of Pt/FMCNTs electrode, in which almost the main Pt nanoparticles are highly dispersed on the electrochemically active sites. The highest Pt utilization obtained in this work is 75.6% for an electrode with 0.12mg/cm2 of Pt loadings.
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