Multi-walled carbon nanotubes modified by sulfated TiO2 – A promising support for Pt catalyst in a direct ethanol fuel cell

We report the synthesis of multi-walled carbon nanotubes coated with sulfated TiO2 (S–TiO2/MWCNTs) as a promising support for Pt catalyst in a direct ethanol fuel cell. Highly dispersed Pt nanoparticles were supported on the S–TiO2/MWCNT composites by NaBH4 reduction procedure (Pt–S–TiO2/MWCNTs). The presence and nature of the catalyst were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy. The size of the sulfated TiO2 product was about 8 nm, and that of the Pt nanoparticle on the S–TiO2/MWCNT composites was about 5 nm. The Pt–S–TiO2/MWCNTs were used to study the electrochemical ethanol oxidation reaction using cyclic voltammetry, chronoamperometry and impedance spectroscopy. The results show that Pt–S–TiO2/MWCNT catalysts show higher catalytic activity for ethanol oxidation compared with Pt supported on non-sulfated TiO2/MWCNT composites and commercial Pt/C catalysts.