A fuel cell with a membrane electrode assembly (MEA) based on Nafion 212 membrane with our Pt-C anode (Pt loading 5.5-30 µg/cm2) and a commercial state-of-the-art Pt/C cathode (Pt loading 300µg/cm2) generated output power up to 1.0 W/cm2 (Fig 1a), value comparable to MEA with commercial powder anode using much higher Pt loading 200-300 µg/cm2. This result demonstrates significant improvement in platinum utilization for HOR due to high dispersion of Pt provided by the magnetron sputtering deposition method. Similarly, a MEA with the commercial Pt/C cathode and our Pt/C thin film (Pt loading 5.5-30 µg/cm2) as anode yielded stable power up to 0.73W/cm2(Fig 1 b), proving its high efficiency for ORR.
Based on the above findings, a MEA with both magnetron sputtered Pt/C electrodes using total Pt loading 20 µg/cm2 was tested with a 4 cm2 cell operating at 70˚C in H2/O2-feed regime for 24 hours. The platinum content on cathode and anode side was chosen 14.4 µg/cm2 and 5.5 µg/cm2, providing highest efficiency for HOR and ORR, respectively. I-V polarization and power density curves were measured with fresh catalyst as well after a 24-hour duration test without any significant lost of efficiency during this period of time (Fig 1c). The magnetron sputtered Pt-C with fine metal dispersion proved to be a promising catalytic material with high Pt utilization for hydrogen-feed PEMFC applications. An additional significant benefit of the Pt-C composite is its lower requirement with respect to feed humidity.