High performance of cup-stacked-type carbon nanotubes as a Pt–Ru catalyst support for fuel cell applications

Abstract

The potential of cup-stacked-type carbon nanotubes (CSCNTs) as a catalyst support for the direct methanol fuel cells has been investigated by the electrochemical oxidation of methanol at various temperatures. The CSCNT-supported platinum–ruthenium $\left(\mathrm{Pt}–\mathrm{Ru}\right)$ bimetallic catalyst exhibited twice as high a power density as the $\mathrm{Pt}–\mathrm{Ru}$ catalyst supported on Vulcan XC-72 carbon, which is widely used as a catalyst support for the DMFC electrodes. The microscopic analysis of the CSCNT-supported $\mathrm{Pt}–\mathrm{Ru}$ catalysts revealed that the bimetallic electrocatalysts were well dispersed on the CSCNT supports, and the particle size of the electrocatalysts was $\mathrm{ca.}5\mathrm{nm}$ . The results of this work indicate that the performance of the carbon support materials is largely influenced by their electrical properties, morphology and crystallographic structures.