Methanol electro-oxidation by nanostructured Pt/Cu bimetallic on poly 3,4 ethylenedioxythiophene (PEDOT)

Abstract

Herein, we report the preparation, characterisation and electrocatalysis of Pt/Cu bimetallic nanostructure formed on Poly 3,4 ethylenedioxythiophene (PEDOT) modified glassy carbon electrode, Pt-Cu-PEDOT/GC. A three-step procedure was adopted for the fabrication of the catalyst. Initially the glassy carbon electrode (GC) was modified by a uniform coating of PEDOT by potential cycling. Copper NPs were then deposited on the PEDOT film by deposition from a 2 mM solution of CuSO4 in 0.1 M NaClO4 at a constant potential of −0.477 V vs. SCE. Pt/Cu-PEDOT/GC catalyst was prepared by substitution of copper by galvanic displacement with various concentrations of H2PtCl6. The electrode thus prepared displayed very good electrocatalytic effect for methanol oxidation characterized by cyclic voltammetry. It was found that the catalyst prepared with 2 mM H2PtCl6 exhibited the highest catalytic activity, with If/Ib values of 1.80 and 1.38 for methanol concentrations of 1 M and 5 M, respectively. At a relatively low Pt loading of 5.48 × 10−6/cm2, the Pt/Cu-PEDOT/GC should be a cost-effective alternative anode catalyst for DMFC.