Abstract
Innovative platinum (Pt) nanostructures were developed in this study for enhancing the catalyst activities and the power density of single cell for proton exchange membrane fuel cell (PEMFC) application. The platinum nanostructures were directly grown on carbon paper by a pulsed electrodeposition technique. The morphology of Pt nanostructures were investigated by SEM, and shown as dendritic structures instead of nanoparticles. The sizes of the dendritic structures were a few nanometers to 3 m in length and 200~450 nm in diameter. A cyclic voltammetry analysis was carried out for characterizing the behavior of methanol oxidation on specimen bearing the Pt dendritic nanostructures in a mixed electrolyte of 1 M methanol and 0.5 M sulfuric acid. It was found that the peak current density of methanol oxidation on the new Pt dendritic nanostructures was as high as 586.5 mA/cm2. The Pt dendritic nanostructures could exhibit a good carbon monoxide tolerance and high efficiency without the incorporation of ruthenium (Ru) catalyst. Based upon the single cell tests, the peak specific power density of PEMFC with the homemade dendritic Pt catalyst was 1140 mW/cm2 and greater than one with the commercial catalysts. The outcome signified a nanostructure catalyst morphology and a significantly improved catalytic activity of the anode or cathode prepared by a pulsed electrodeposition technique.