Dispersion of Pt/Ru catalyst onto arc-soot and its performance evaluation as DMFC electrode

Abstract

Abstract The arc-soot (AS) nano-carbon was synthesized by using arc discharge apparatuses which were the conventional arc apparatus and the new twin-torch-arc apparatus. AS synthesized with the conventional arc apparatus contained cocoon-like carbon nano-horn (CNH), dahlia-like CNH, and graphite ball. On the other hand, AS which was synthesized using the new twin-torch-arc apparatus contained mainly cocoon-like CNH and dahlia-like CNH, and contained a little graphite ball. The quality of dispersion was characterized and evaluated by the index of dispersion which was based on a diameter and a number density of catalyst particles. The electrocatalystic activity of the Pt/Ru catalysts was evaluated by the methanol-impregnated paper burning method. If the index of dispersion of the AS was high, then the AS burned violently. In the dispersion process, the optimum dispersion temperature obtained was 150 °C. Some MEAs of DMFC cell consisted of each Pt/Ru–AS catalyst which had different characteristics. It was observed that the power density increased with the index of dispersion. It was suggested that the power density of DMFC increased by 500% with a 350% increase in the index of dispersion. Pt/Ru–AS catalyst used AS, which was synthesized using the new twin-torch-arc apparatus, was better than Pt/Ru–AS catalysts using AS which were synthesized with the conventional arc apparatus to apply for the catalyst of DMFC.