A self-humidifying composite membrane with self-assembled Pt nanoparticles for polymer electrolyte membrane fuel cells

A method for preparing a self-humidifying composite membrane for the polymer electrolyte membrane fuel cells (PEMFCs) is presented. In this method, perfluorosulfonylfluroride resin is impregnated into a PTFE porous support and positively charged poly(diallymethylammonium)-Pt nanoparticles are self-assembled into the composite membrane to form a self-humidifying layer. The self-assembled Pt nanoparticles were dispersed uniformly in the composite membrane and serve as the catalytic center for the combination reaction between the crossover hydrogen and oxygen, effectively self-humidifying the membrane. The self-assembly of Pt nanoparticles has little adverse effect on the proton conductivity of the composite membrane. The composite membrane with self-assembled Pt nanoparticles improves significantly the performance of PEMFCs as compared to that of the composite membrane without self-assembled Pt nanoparticles. The results show that optimum loading of the self-assembled Pt nanoparticle is about 8.87–9.57μg/cm 2
8.87–9.57μg∕cm2 under conditions of the present study.