Self-Assembly of PDDA-Pt Nanoparticle∕Nafion Membranes for Direct Methanol Fuel Cells

The development of direct methanol fuel cells (DMFC) based on perfluorosulfonic polymers such as Nafion has been retarded by the significant methanol crossover. Here we report a methanol blocking technique based on the electrostatic self-assembly of positively charged poly(diallyldimethylammonium chloride) (PDDA)-Pt nanoparticles to the negatively charged sulfonic acid groups, , present at the Nafion membrane surface. The methanol crossover current is reduced from for pure Nafion 1135 membrane to for the Nafion 1135 membrane modified by the self-assembly of PDDA-Pt nanoparticles at , a reduction in methanol permeability by 46%. The maximum power density of the cell based on the self-assembled PDDA-Pt nanoparticles∕Nafion 1135 membrane is , which is 32% higher than for the cell based on the unmodified Nafion 1135. The self-assembly technique shows a great potential for the development of Nafion membranes with low methanol crossover for DMFC.