Direct methanol fuel cells (DMFC) have several advantages for a broad spectrum of energy-demanding applications, ranging from portable devices to stationary backup power. DMFCs deliver power at high efficiencies and use methanol as fuel, with a high energy density; therefore, fuel storage volume requirements are reduced. However, DMFCs face several technical obstacles, such as methanol crossover through the Nafion® membrane and slow methanol oxidation reaction (MOR) kinetics at the anode that impedes its performance. Therefore, we placed a methanol oxidation scavenger layer within the proton conducting membrane to reduce methanol crossover to the cathode. The layer was made using commercial PtRu/C catalyst particles embedded within a perfluorosulfonic acid (PFSA) ionomer matrix. We experimented with various catalyst ink formulations and fabrication techniques. We found that the overall performance of the DMFC, including the mass activity of the cathode, was significantly improved due to the reduction of methanol crossover while maintaining a reasonable proton conductivity.

This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Fuel Cell Technologies Office (FCTO) under Award Number DE-EE0008440.