Figure 7: Single-cell performance.

(a) Polarization and power-density curves for PEMFCs, using a Au–Pd₆CoCu/C cathode catalyst at 25, 60 and 80 °C. (b) Polarization and power-density curves for PEMFCs using a Pd₆CoCu/C cathode catalyst at 25, 60 and 80 °C. (c) Stability evaluation of Au–Pd₆CoCu/C and Pd₆CoCu/C cathodes on polarizing the cell at 0.42 V for 100 h in a single cell at 80 °C. (d) Comparison of the polarization and power densities for PEMFCs using a Au–Pd₆CoCu/C and Pd₆CoCu/C cathode catalyst after life test at 80 °C. Pt/C (Alfa Aesar, 40wt%) was used as the anode catalyst, and the metal loading was 0.5 mg cm⁻² in both the anode and cathode. The current density values given are with respect to geometric electrode area.