Facile synthesis of PdNi nanowire networks supported on reduced graphene oxide with enhanced catalytic performance for formic acid oxidation

This paper reports a simple method, in which Ni nanoparticles act as seeds for the formation of reduced graphene oxide (RGO) supported PdNi nanowire networks. The as-prepared catalysts were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD) and Xray photoelectron spectroscopy (XPS). Electrochemical measurements proved that the PdNi-NNs/RGO catalyst has superior electrocatalytic activity towards the formic acid oxidation reaction with much larger electrochemically active surface area and mass activity as well as higher long term-stability in comparison with the Pd/RGO and commercial Pd/C catalysts. The optimized ratio of Pd and Ni is 1 : 1, tuned by simply adjusting the feed ratio of the precursors as well. It is proposed that the improvement of the catalytic performance is attributed to the special nanostructure and the synergistic effect between Pd and Ni. These findings highlight the facile synthesis of the PdNi nanowire networks on RGO sheets and their promising application as electrocatalysts for fuel cells.