Preparation and characterization of core-shell structured catalysts using PtxPdy as active shell and nano-sized Ru as core for potential direct formic acid fuel cell application

Carbon-supported core-shell structured Ru@PtxPdy/C catalysts with PtxPdy as shell and nano-sized Ru as core are prepared by a successive reduction procedure. The catalysts are extensively characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The formic acid oxidation activity of Ru@PtxPdy/C varies with the varying Pt:Pd atomic ratio. The peak oxidation potential on Ru@Pt1Pd2/C shifts negatively for about 200 mV compared with that of Pd/C. The higher electro-catalytic activity toward formic acid oxidation on core-shell structured Ru@PtxPdy/C catalyst than that on PtxPdy/C suggests the high utilization of noble metals. In addition to the enhanced noble metal utilization, Ru@PtxPdy/C catalyst also shows improved stability as evidenced by chronoamperometric evaluations. (C) 2010 Elsevier Ltd. All rights reserved.