Chitosan–phosphotungstic acid complex as membranes for low temperature H2–O2 fuel cell

•Freestanding chitosan/H3PW12O40 membranes were made by in situ ionotropic gelation.•Open circuit potential was up to 0.95 V using such membranes in H2–O2 PEMFC at 25 °C.•A maximum power density of 350 mW cm−2 was obtained at 25 °C.•The conductivity of the membrane was up to 18 mS cm−1.

Free-standing Chitosan/phosphotungstic acid polyelectrolyte membranes were prepared by an easy and fast in-situ ionotropic gelation process performed at room temperature. Scanning electron microscopy was employed to study their morphological features and their thickness as a function of the chitosan concentration. The membrane was tested as proton conductor in low temperature H2–O2 fuel cell allowing to get peak power densities up to 350 mW cm−2. Electrochemical impedance measurements allowed to estimate a polyelectrolyte conductivity of 18 mS cm−1.