Directly Grown Carbon Nanotubes Applied in Direct Methanol Fuel Cell

Abstract

Carbon nanotubes (CNTs) were directly grown on a carbon cloth (DGCNTs), which were employed as the electrocatalyst support in the direct methanol fuel cell (DMFC). The CNTs were prepared by an iron-assisted catalyst grown method using the microwave plasma-enhanced chemical vapor deposition. From the morphological analysis, the as-prepared DGCNT is a multi-walled and bamboo-like structure with a diameter of 10-20 nm. The Pt-Ru electrocatalysts were deposited on the DGCNTs using sputtering process (Pt-Ru/DGCNT), which were acted as an anode in the DMFC. The diameters of Pt-Ru nanoparticles deposited on the DGCNTs are ca. 3.54 nm, which are the high-degree alloy by X-ray diffraction analysis. For fabricating a membrane electrode assembly (MEA), 0.2 mg/cm^2 Pt-Ru/DGCNT and 4.0 mg/cm^2 Pt black deposited on carbon cloth were employed as the anode and cathode, respectively, which the Nafion 117 was sandwiched in between the electrodes by a hot-pressing process. The polarization curve shows that the maximum power density is ca. 1.52 W/Pt-mg feeding 1 M methanol and pure oxygen to the anode and cathode, respectively, operating at 60℃. The low amount of precious metal loaded on DGCNTs applied in a MEA shows a high performance, which is suitable for a DMFC.