Performance and stability characteristics of MEAs with carbon-supported Pt and Pt1Ni1 nanoparticles as cathode catalysts in PEM fuel cell

Polarization curves of membrane electrode assemblies (MEAs) containing carbon-supported platinum (Pt/C) and platinum–nickel alloy (Pt1Ni1/C) as cathode catalysts were obtained for durability test as a function of time over 1100 h at constant current. Charge transfer resistance was measured using electrochemical impedance spectroscopy and postmortem analysis such as X-ray diffraction and high-resolution transmission electron microscopy was conducted in order to elucidate the degradation factors of each MEA. Our results demonstrate that the reduced performance of MEAs containing Pt1Ni1/C as a cathode catalyst was due to decreased oxygen reduction reaction caused by the corrosion of Ni, whereas that of MEAs containing Pt/C was because of reduced electrochemical surface area induced by increased Pt particle size.