PdAg alloy nanotubes with porous walls for enhanced electrocatalytic activity towards ethanol electrooxidation in alkaline media

Direct alcohol fuel cells (DAFCs) has been recognized as a green and substantial energy source in the near future. Due to the excellent electrocatalytic activities of palladium-based electrocatalysts for alcohol oxidation in alkaline medium, controllable synthesis of Pd-based bimetallic nanocrystals to maximize its activity while simultaneously decreasing the required amount of Pd is very important for the commercializaiton of DAFCs. Here, a novel PdAg naocrystal with unique structure is synthesized by the galvanic replacement reaction between pre-synthesized Ag nanowires and palladium precursor. X-ray diffraction and high-resolution transmission electron microscopy demonstrate that the obtained PdAg naocrystals display a tubular alloy nanostructure with hollow interiors and porous walls. Moreover, the electrochemical studies indicate that the as-prepared PdAg alloy nanotubes (PdAg-ANTs) exhibit excellent electrocatalytic activity and stability towards ethanol electrooxidation in alkaline media, showing its great potential for use as anode catalysts in alkaline DAFCs. The enhanced electrocatalytic activity of the prepared PdAg-ANTs can be attributed to the formation of alloy between Ag and Pd atoms, structural effect and the unique nanostructure.