Novel hybrid membranes based on polybenzimidazole and ETS-10 titanosilicate type material for high temperature proton exchange membrane fuel cells: A comprehensive study on dense and porous systems

Novel hybrid membranes based on polybenzimidazole (PBI) and ETS-10 titanosilicate type materials functionalized with sulfonic groups have been developed for high temperature PEMFC applications. In particular, 45% porous ETS-10/PBI electrolyte membranes in porosity have been reported for the first time in this work. A clear conduction outperforming is shown by porous PBI + 3 wt.% SO3H-ETS-10 doped at 50 °C, attaining “in-plane” conductivity values up to 74 mS cm−1 at 180 °C under dry N2 flow. The transport selectivity of the as prepared dense and porous PBI based membranes has been evaluated by comparison of “in-plane” conductivity/methanol permeability values at 50 °C, 100 °C and 150 °C. Accounting from that, dense pure PBI membranes are preferred at 50 °C (4.7 × 106 S·s·bar mol−1); whereas at 150 °C, dense PBI + 3% SO3H-ETS-10 counterparts exhibit the higher conductivity/methanol permeability ratio (2.5 × 108 S·s·bar mol−1).