Low-Defect MWNT-Pt Nanocomposite as a High Performance Electrocatalyst for Direct Methanol Fuel Cells

A nanocomposite of low-defect multiwalled carbon nanotubes (MWNTs) and platinum particles was synthesized by an improved soft chemical route, and its electrocatalytic activities for methanol oxidation were investigated. Our approach does not require cumbersome premodification of carbon nanotubes (CNTs) and the reduction by hydrogen at higher temperatures for the nanocomposite. Transmission electron microscopic observation reveals that Pt nanoparticles with diameters ranging from 2 to 5 nm are uniformly dispersed on the CNT surface. Raman spectroscopy confirms that the MWNTs have a low defect density. This low-defect MWNT-Pt nanocomposite exhibits high electric conductivity (the charge transfer resistance is 24.99 Omega) and excellent electrocatalytic activity (the forward anodic peak current density is 47.37 mA/cm(2)) as well as CO-poisoning tolerance (the ratio of the forward anodic peak current to the reverse anodic peak current is 2.94), which demonstrate that the role of low-defect carbon nanotubes is very effective as a support material in the development of an electrocatalyst.