Pt Nanoparticles Loaded on W₁₈O₄₉ Nanocables-rGO Nanocomposite as a Highly Active and Durable Catalyst for Methanol...

Highly active and durable electrocatalysts are vital for commercialization of direct methanol fuel cells. In this work, a three-dimensional nanocomposite consisting of platinum nanoparticles, W₁₈O₄₉ nanocables, and reduced graphene oxide composite (Pt/W₁₈O₄₉ NCs-rGO) has been prepared as an electrocatalyst for methanol oxidation reaction (MOR). The catalyst is prepared through a two-step method. The W₁₈O₄₉ nanocables and the reduced graphene oxide composite are prepared by a solvothermal process. Then, Pt nanoparticles are loaded on the W₁₈O₄₉ nanocables and the reduced graphene oxide composite by a hydrogen reduction at ambient condition. The obtained catalyst has a special three-dimensional architecture consisting of two-dimensional nanosheets, assembled one-dimensional nanocables, and the loaded nanoparticles on their surface. The Pt/W₁₈O₄₉ NCs-rGO catalyst shows 1.56 time mass activities than the Pt/C, with the current density of the forward anodic peak reaching 1624 mA/mg_Pt at 0.854 V versus reversible hydrogen electrode potential in 0.1 M HClO₄ and 0.5 M CH₃OH mixed electrolyte. It also shows a strong antipoisoning property toward CO. For the durability testing, the current density of Pt/W₁₈O₄₉ NCs-rGO shows a 37% decay, whereas the current of Pt/C catalyst shows a 41% degradation from 600 to 3600 s at 0.7 V. The high activity toward MOR, good antipoisoning for intermediate products, and excellent stability are ascribed to strong metal-support interaction effects between the Pt nanoparticles and the W₁₈O₄₉ NCs.