Electrocatalytic oxidation of methanol at 2-aminophenoxazin-3-one-functionalized multiwalled carbon nanotubes supported PtRu nanoparticles

A new process to prepare well-dispersed PtRu nanoparticles on 2-aminophenoxazin-3-one (APZ)-functionalized multiwalled carbon nanotubes (PtRu/APZ-MWCNTs) was reported. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), UV-vis absorption spectra as well as Raman spectra were used for the catalyst characterization. The Raman spectroscopic results reveal that APZ-functionalized MWCNTs has good integrity and electronic structure than MWCNTs treated with chemical acid. The composite catalyst shows excellent electrocatalytic activity toward methanol oxidation and appears as a promising candidate for use in direct methanol fuel cells. Cyclic voltammetry and chronoamperometry studies indicate that the PtRu/APZ-MWCNTs catalysts exhibited higher electrochemical active surface area, electrocatalytic activity and stability for the electro-oxidation of methanol as compared to that of PtRu electrocatalysts supported on conventional acid-treated MWCNTs and carbon black. (C) 2009 Elsevier Ltd. All rights reserved.