Sulfated SnO2 modified multi-walled carbon nanotubes – A mixed proton–electron conducting support for Pt catalysts in direct ethanol fuel cells

Abstract

We report on the synthesis of sulfated SnO2 modified multi-walled carbon nanotubes (MWCNTs) composites as new supports of Pt catalyst (Pt–S-SnO2/MWCNTs) with the aims to enhance electron and proton conductivity and also catalytic activity for ethanol oxidation. The Pt–S-SnO2/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-SnO2/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-SnO2/MWCNTs catalyst for ethanol oxidation reactions are investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that Pt–S-SnO2/MWCNTs catalyst exhibits higher catalytic activity for ethanol oxidation than Pt supported on non-sulfated SnO2/MWCNTs composites.