Pt supported self-assembled nest-like-porous WO3 hierarchical microspheres as electrocatalyst for methanol oxidation

Hexagonal tungsten trioxide (hex-WO3) hierarchical microspheres with nest-like pores are synthesized by a facile hydrothermal method. The nest-like-porous (NLP) WO3 hierarchical microspheres with 5–6 μm in diameters are self-assembled of single-crystal nanowires. The nanowires have lengths of several hundred nanometers and diameters of 5–30 nm; the long axis of nanowire is oriented toward 〈0 0 1〉 direction. The specific surface area of hex-WO3 microspheres is 62 m2 g−1. 20 wt.% Pt nanoparticles with ∼7 nm are loaded onto the WO3 microspheres using a conventional microwave-assisted ethylene glycol (EG) method. The electrocatalytic activity for methanol oxidation of Pt/NLP-WO3 microspheres is investigated by cyclic voltammetry and chronoamperometry. Due to the large tunnels of hexagonal structure and high porous surface morphology, great enhancement of electrochemical performance is achieved. The Pt/NLP-WO3 microspheres are demonstrated to be a promising anode material for direct methanol fuel cells (DMFC).

► Nest-like-porous (NLP) WO3 microspheres are assembled by a hydrothermal method.
► The NLP-WO3 microspheres have a hexagonal structure and high porous surface.
► Great enhancement of electrochemical property is achieved for Pt/NLP-WO3 microspheres.