Gas diffusion electrodes containing ZHP/Nafion for PEMFC operation at 120 °C

Gas diffusion electrodes (GDEs) incorporating zirconium hydrogen phosphate (ZHP) and Nafion ionomer are investigated in order to examine the influence of ZHP on the properties of catalyst layers (CL) for high temperature polymer electrolyte fuel cells (PEMFCs). ZHP/Nafion-GDEs contained 20 wt% ZHP based on Nafion. GDEs were characterized by SEM, TEM, and FT-IR. Fuel cell polarization curves for ZHP/Nafion-GDE cathodes and anodes were evaluated at temperatures ranging from 80 to 120 °C and relative humidities of 100% to 35%. ZHP/Nafion-containing anodes gave similar polarization curves to Nafion-GDEs below 100 °C but provided higher fuel cell performance above 100 °C. Thermal gravimetric analysis indicated that the presence of ZHP marginally increased the water content in the catalyst layer above 100 °C and EIS analysis indicated that ZHP increased protonic conductivity of the catalyst layer. In contrast, no such increase in performance was observed for ZHP/Nafion-GDE cathodes compared to Nafion-GDEs.