Optimization of electrode properties for low temperature DMFC applications

The effect of modification of DMFC electrode structures for low temperature operation, under forced convection flow and passive mode operation, was evaluated. Regarding the anode, it was found that a reduction of Nafion content in the catalytic layer produces an increase of performance at low temperatures. Also an enhancement of anode GDL hydrophilicity and increase of pore volume could be favorable for the process. For what concerns the cathode, a high hydrophobicity, useful to counteract the effect of flooding, appears mainly appropriate for operation at low temperatures (<= 30°C). At higher temperatures (e.g. 60°C) an increase of ohmic resistance occurs as a consequence on the increase of hydrophobicity for the cathode layer.