Water-confined CuFe Prussian blue analogues empower Nafion membranes for high-temperature/low-humidity fuel cells.

To combat Nafion dehydration under high-temperature, low-humidity conditions, we engineered a CuFe-PBA/Nafion composite membrane by integrating edge-passivated CuFe Prussian blue analogue nanocubes. The 1.0 wt% composite membrane attains a proton conductivity of 72 mS cm-1 at 80 °C/75% relative humidity (RH) and a peak power density of 908 mW cm-2 at 110 °C/40% RH, while maintaining mechanical and Fenton oxidative stability.