Highly conductive, crosslinked ionomers based on poly(styrene-co-maleic anhydride) for water electrolysis

Hydrogen production through water electrolysis calls for a low-cost non-fluoro membrane to make the process economically viable due to the high cost and environmental concerns of the current fluorinated ionomers. Here, we present such an ionomer with high proton conductivity based on the hybrid of commercially available poly(styrene-co-maleic anhydride) and polyhedral oligomeric silsesquioxane (POSS). The three-dimensional POSS framework, which does not only act as a robust scaffold but also provides binding sites for water, contributes to the amount of bound water, high proton conductivity and good oxidative stability.