Polyelectrolyte based on tetra-sulfonated poly(arylene ether)s for direct methanol fuel cell

► We synthesized novel tetra-sulfonated poly(arylene ether ketone)s as PEM materials. ► The membranes exhibited lower water uptake and swelling ratio than Nafion 117. ► Combination of considerable proton conductivity and low methanol permeability. ► The membranes are promising candidate PEM materials for direct methanol fuel cell.