Proton transport, water uptake and hydrogen permeability of nanoporous hematite ceramic membranes

► Mesoporous acid-free hematite ceramic membranes have been studied as proton conductors. ► The highest value of proton conductivity (Grotthuss mechanism) was found to be 2.76 × 10−3 S cm−1 at 90 °C and 81% RH. ► The lower cost and higher hydrophilicity of these ceramic membranes make them potential substitutes for perfluorosulfonic polymeric membranes in PEMFCs.