Carbon-supported Cu@Ag core-shell nanoparticles are prepared by a successive reduction method in an aqueous solution and are used as an anode electrocatalyst for the direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties of the as-prepared electrocatalysts are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry (CV), chronopotentiometry (CP), and fuel cell tests. In situ Fourier transform infrared (FTIR) spectroscopy is employed in 2 M NaOH/0.1 M NaBH4 to understand the borohydride oxidation reaction (BOR) mechanism by studying the intermediate reactions occurring on the Cu@Ag/C electrode. The TEM images show that the average size of the Cu-1@Ag-1/C particles is approximately 18 nm. Among the as-prepared catalysts, the Cu-2@Ag-1/C catalyst presents the highest catalytic activity. As shown by in situ FTIR, the oxidation reaction mechanism of BH4- is similar to that of Ag/C: BHn(OH)(4-n)(-) + 20H(-) -> BHn-1 (OH)(5-n)(-) + H2O + 2e. At 25 degrees C, the DBHFC with Cu-2@Ag-1/C as the anode electrocatalyst and Pt mesh (1 cm(2)) as the cathode electrode exhibits a maximum anodic power density of 17.27 mW mg(-1) at a discharge current density of 27.8 mA mg(-1). (C) 2015 Elsevier B.V. All rights reserved.