Synthesis and characterization of Nafion-stabilized Pt nanoparticles for polymer electrolyte fuel cells

Platinum nanoparticles are synthesized by alcohol reduction method using Nafion as a stabilizer under various conditions such as the Nafion/Pt molar ratio and reflux temperature. Nafion–Pt nanoparticles are characterized by agglomeration and the particle size is typically in the range of 2–4 nm. The electrocatalytic activity of Nafion–Pt nanoparticles for polymer electrolyte and direct methanol fuel cells (PEFCs and DMFCs) is investigated in comparison to that of unsupported Pt black and carbon-supported Pt/C electrocatalysts. Nafion–Pt nanoparticles prepared with low Nafion/Pt ratios show higher and/or comparable activities towards O2 reduction reaction in the absence and presence of methanol in comparison to that of Pt black and Pt/C electrocatalysts. In contrast, the electrocatalytic activity of the Nafion–Pt nanoparticles for the methanol oxidation reaction is very low. The results indicate that Pt nanoparticles embedded in Nafion polyelectrolyte are potential methanol tolerant electrocatalysts for the O2 reduction reaction in DMFCs.