Activated carbon nanotubes-supported catalyst in fuel cells

The electrochemical property of platinum loaded on activated carbon nanotubes (Pt/ACNTs) was investigated by cyclic voltammograms (CVs) recorded in H2SO4 and H2SO4/CH3OH aqueous solutions, respectively. Compared to 0.0046 A/cm2 of Pt-loaded on pristine carbon nanotubes (Pt/CNTs) with a SBET of 164 m2/g and 0.0042 A/cm2 of conventional carbon black (Pt/C, Vulcan XC-72) with a SBET of ∼250 m2/g, a better electrochemical activity (a high current density of 0.0070 A/cm2 for weak-H2 adsorption/desorption) of the Pt/ACNTs with high specific surface area (SBET) of 830–960 m2/g was obtained. Furthermore, the highest current density of 0.079 A/cm2 at 0.65 V in anodic sweep was observed during the methanol oxidation. On the basis of Pt size, utility ratio, and electro-active specific surface area (EAS), the Pt/ACNTs with a high Pt-loading of 50 wt.% exhibited the best electrochemical activity. The present ACNTs may be an excellent support material for electrochemical catalyst in proton exchange membrane and direct methanol fuel cells.