An in situ carbonization-replication method to synthesize mesostructured WO₃/C composite as nonprecious-metal anode catalyst in PEMFC

A meostructured WO₃/C composite with crystalline framework and high electric conductivity has been synthesized by a new in situ carbonization-replication route using the block copolymer (poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)) present in situ in the pore channels of mesoporous silica template as carbon source. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, thermogravimetry differential thermal analysis, and N₂ adsorption techniques were adopted for the structural characterization. Cyclic voltammetry, chronoamperometry, and single-cell test for hydrogen electrochemical oxidation were adopted to characterize the electrochemical activities of the mesoporous WO₃/C composite. The carbon content and consequent electric conductivity of these high-surface-area (108-130 m² g^-1) mesostructured WO₃/C composite materials can be tuned by variation of the duration of heat treatment, and the composites exhibited high and stable electrochemical catalytic activity. The single-cell test results indicated that the mesostructured WO₃/C composites showed clear electrochemical catalytic activity toward hydrogen oxidation at 25 °C, which makes them potential non-precious-metal anode catalysts in proton exchange membrane fuel cell. Holy C/O₃W! Meostructured WO₃/C composites with crystallized framework and high electric conductivity were synthesized by a new in situ carbonization-replication route. The length of the heat treatment governs the carbon content and electric conductivity. The composites show high and stable electrochemical catalytic activity for hydrogen oxidation and are potential non-precious-metal anode catalysts for proton exchange membrane fuel cells.