Sulfated SnO_2 modified multi-walled carbon nanotubes - A mixed proton-electron conducting support for Pt catalysts in direct ethanol fuel cells

摘要

We report on the synthesis of sulfated SnO_2 modified multi-walled carbon nanotubes (MWCNTs) composites as new supports of Pt catalyst (Pt-S-SnO_2/MWCNTs) with the aims to enhance electron and proton conductivity and also catalytic activity for ethanol oxidation. The Pt-S-SnO_2/MWCNTs catalyst is synthesized by a combination of improved sol-gel and pulse-microwave assisted polyol methods. The surface presence, morphology and structure of the Pt-S-SnO_2/MWCNTs catalyst are characterized by Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD), respectively. The electrocatalytic properties of the Pt-S-SnO_2/MWCNTs catalyst for ethanol oxidation reactions are investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that Pt-S-SnO_2/MWCNTs catalyst exhibits higher catalytic activity for ethanol oxidation than Pt supported on non-sulfated SnO_2/MWCNTs composites.