High performance proton-conducting composite based on vanadium-substituted Dawson-type heteropoly acid for proton exchange membranes

Proton exchange membranes (PEMs) are the key parts in proton exchange membrane fuel cells (PEMFCs). In this work, a proton-conducting composite membrane rGO-P2W16V2@SPEEK was synthesized from vanadium-substituted Dawson-type heteropoly acid (H8P2W16V2O62
- 20H2O, abbreviated as P2W16V2), sulfonated polyether ether ketone (SPEEK) and reduced graphene oxide (rGO). Characterizations proved the integrity of the Dawson-structure heteropoly acids (HPAs) in composites and the uniform inorganic-organic hybrid distribution. The membrane shows excellent proton conductivity of 7.90 × 10−2 S cm−1 at 50 °C and the proton conduction was proved to comply with the Grotthuss mechanism. Up to now, this is the first time that a Dawson-type HPA was reported for the application of PEMs and this work extended the application of polyoxometalate-based materials in the field of fuel cells.