Pt-Ru decorated self-assembled TiO_2-carbon hybrid nanostructure for enhanced methanol electrooxidation

摘要

Porous titanium oxide-carbon hybrid nanostructure (TiO_2-C) with a specific surface area of 350 m~2/g and an average pore-radius of 21-8 A is synthesized via supramolecular self-assembly with an in situ crystallization process. Subsequently, TiO_2-C supported Pt-Ru electro-catalyst (Pt-Ru/TiO_2-C) is obtained and investigated as an anode catalyst for direct methanol fuel cells (DMFCs). X-ray diffraction, Raman spectroscopy and transmission electron microscopy (TEM) have been employed to evaluate the crystalline nature and the structural properties of TiO_2-C. TEM images reveal uniform distribution of Pt-Ru nanoparticles (d_(Pt_Ru) = 1.5-3.5 nm) on TiO_2-C. Methanol oxidation and accelerated durability studies on Pt-Ru/TiO_2-C exhibit enhanced catalytic activity and durability compared to carbon-supported Pt-Ru. DMFC employing Pt-Ru/TiO_2-C as an anode catalyst delivers a peak-power density of 91 mW/cm~2 at 65 °C as compared to the peak-power density of 60 mW/cm2 obtained for the DMFC with carbon-supported Pt-Ru anode catalyst operating under similar conditions.