Electrochemical characterization of platinum-based anode catalysts for membraneless fuel cells

摘要

In the present work, carbon-supported Pt-Sn, Pt-Ru, and Pt-Sn-Ru electrocatalysts with different atomic ratios were prepared by alcohol-reduction method to study the electro-oxidation of ethanol in membraneless fuel cells. The synthesized electrocatalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses. The prepared catalysts had similar particle morphology, and their particle sizes were 2-5 nm. The electrocatalytic activities were characterized by cyclic voltammetry (CV) and chronoamperometry (CA). The electrochemical results obtained at room temperature showed that the addition of Sn and Ru to the pure Pt electrocatalyst significantly improved its performance in ethanol electro-oxidation. The onset potential for ethanol electro-oxidation was 0.2 V vs. Ag/AgCl, in the case of the ternary Pt-Sn-Ru/C catalysts, which was lower than that obtained for the pure Pt catalyst (0.4 V vs. Ag/AgCl). During the experiments performed on single membraneless fuel cells, Pt-Sn-Ru/C (70:10:20) performed better among all the catalysts prepared with power density of 36 mW/cm(2). The better performance of ternary Pt-Sn-Ru/C catalysts may be due to the formation of a ternary alloy and the smaller particle size.