Controlled synthesis of Pt/CS/PW₁₂-GNs composite as an anodic electrocatalyst for direct methanol fuel cells

Controlled assembly in aqueous solution was used to synthesize the well-organized Pt/CS/PW₁₂-GNs composite. By the aid of linear cationic polysaccharide chitosan, 2-D distribution worm-like Pt nanoparticles with their length and width of 15–20 and 3–4 nm, respectively, were formed on the surface of CS/PW₁₂-GNs using HCOOH as a reducing agent at room temperature. The introduction of CS leads to well dispersion of worm-like Pt nanoparticles, the electroactivity of H₃PW₁₂O₄₀ (PW₁₂) alleviates CO poisoning toward Pt particles, and graphene nanosheets (GNs) ensure excellent electrical conductivity of the composites. The combined action among different components results in significantly enhanced catalytic activity of Pt/CS/PW₁₂-GNs toward methanol oxidation and better tolerance of CO. The as-synthesized Pt/CS/PW₁₂-GNs exhibit the forward peak current density of 445 mA mg⁻¹, which is much higher than that (220 mA mg⁻¹) for Pt/C-JM (the commercially available Johnson Matthey Hispec4000 catalyst, simplified as Pt/C-JM) and some recently reported Pt/graphene-based nanomaterials. The construction of 2-D distribution worm-like Pt nanoparticles and facile wet chemical synthesis strategy provide a promising way to develop superior performance electrocatalysts for direct methanol fuel cells applications.