High Conductivity and Surface Area of Mesoporous Ti0.7W0.3O₂ Materials as Promising Catalyst Support for Pt in Proton-Exchange Membrane Fuel Cells.

Abstract

In this work, mesoporous Ti0.7W0.3O₂ materials with high conductivity and surface area as promising catalyst support for Pt in Proton-Exchange Membrane Fuel Cells (PEMFCs) were synthesized via a single-step solvothermal process at low-temperature without using any surfactants or stabilizers. The characterizations of material are measured via XRD, TEM, SEM-EDS, and BET as well as electronic conductivity measurement. As a result, Ti0.7W0.3O₂ formed a homogenous solid solution with mesoporous anatase-TiO₂ structure and uniformly spherical nanoparticles morphology of about ~10 nm diameter, together with a high electrical conductivity of 0.022 S/cm compared to that of undoped-TiO₂ (1.37×10-7 S/cm), which implied that tungsten (VI) ions was successfully doped into anatase-TiO₂ lattices. The N₂ adsorption/desorption isotherms indicated that Ti0.7W0.3O₂ is being mesoporous structure with high surface area up to ~202 m²/g, which is nearly similar to that of the commercial Vulcan XC72 (~232 m²/g). The Pt nanoparticles was easily anchored onto Ti0.7W0.3O₂ surface by the chemical reduction process using NaBH4 as a reducing agent. The spherical Pt nanoparticles of ~9 nm in diameter were deposited uniformly on the mesoporous support. These results suggested that mesoporous Ti0.7W0.3O₂ materials synthesized are promising catalyst supports to replace carbon-based supports for Proton-exchange membrane fuel cells.