Platinum decorated on partially exfoliated multiwalled carbon nanotubes as high performance cathode catalyst for PEMFC

Abstract

We report a significant increase in the performance of a hybrid carbon structure of one dimensional (1D) multi-walled carbon nanotubes (MWNTs) and 2D graphene sheets as the catalyst support material for proton exchange membrane fuel cells. A few upper layers of multiwalled carbon nanotubes were cut open in the longitudinal direction to achieve a hybrid structure of opened up MWNTs as graphene “wings” attached to the unaffected inner tubes by modifying the chemical oxidation method followed by hydrogen induced reduction technique. These partially exfoliated nanotubes (PENTs) were used as the support material for Pt deposition using chemical reduction with ethylene glycol. These PENTs supported Pt catalysts were used for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). An enhanced performance of 1000 mW/cm2 compared to a cell with a commercial Pt/C (418 mW/cm2) was achieved which was attributed to the specific structure of the support material giving an improved effectual surface area as well as higher conductivity.