Evaluation of the Durability of Polymer Electrolyte Membranes in Fuel Cells Containing Pt/C and Pt-Co/C Catalysts Under Accelerated Testing

摘要

A major degradation source in proton exchange membrane fuel cells results from radical attack of the membrane. Radicals form on the electrodes and at the platinum band in the membrane. Platinum alloys have enhanced durability in fuel cells and it is hypothesized that the higher durability of PtCo/C electrodes will translate into less Pt band formation and therefore higher membrane durability. To investigate the effect of Pt/C vs. PtCo/C on membrane durability, CCMs were prepared with either Pt/C or PtCo/C in their electrodes and accelerated degradation studies were carried out. Use of PtCo/C rather than Pt/C in the electrode resulted in much lower CCM degradation. It is postulated that the use of PtCo/C reduces Pt band formation in the membrane, resulting in decreased membrane degradation. This postulation is supported by the presence of a platinum band in the CCM containing Pt/C, but not in the one containing PtCo/C after testing.