A high-performance direct methanolfuel cell with a polymer fiber membrane and RuO2/CNTs as a cathode catalyst

Abstract

An innovative direct methanol fuel cell (DMFC) has been developed by the introduction of a polymer fiber membrane (PFM) as a substitute for the polymer electrolyte membrane (PEM). The PFM is, however, penetrable to all ions in the electrolyte and acts as an insulator between the electrodes. The new structured cell requires the cathode catalyst to be tolerant to methanol fuel and to reduce O₂ simultaneously. A catalyst system, RuO₂/CNTs, has been found to satisfy the requirements. The RuO₂/CNTs exhibits good oxygen reduction reaction (ORR) activity, methanol-tolerance and stability. A maximum power density of 136.9 mW cm⁻² has been achieved at 70 °C in 5 M CH₃OH + 6 M KOH electrolyte, which is almost three times higher than that achieved when employing the Nafion-117 membrane.