Ethylene glycol stabilized NaBH4 reduction for preparation carbon-supported Pt–Co alloy nanoparticles used as oxygen reduction electrocatalysts for microbial fuel cells

摘要

Three carbon-supported Pt–Co alloys with varying Pt to Co atom ratio (Pt_2–Co/C, Pt–Co/C, Pt–Co_2/C) were prepared by NaBH_4 reduction in ethylene glycol at room temperature. As supported by X-ray diffraction, all the prepared Pt–Co nanoparticles have a single-phase face-centered cubic structure. Transmission electron microscopy indicates that all nanoparticles have small particle-size range and are highly dispersed on carbon support. Catalytic properties of the synthesized Pt–Co alloy catalysts were analyzed using cyclic voltammetry and linear sweep voltammetry methods, and the results suggested that Pt–Co/C catalysts exhibit the best Pt mass activity and the highest stability for the oxygen reduction reaction (ORR) when compared with Pt/C catalyst and other Pt–Co alloy catalyst in both acidic and neutral media. Kinetic analysis reveals that the ORR on Pt–Co alloy follows the four-electron pathway leading to water. As the cathode catalyst, the single-chamber microbial fuel cell tests indicated the much better performance of Pt–Co alloy than that of commercial Pt/C.