▎ 摘　　要

The development of highly active and inexpensive electrode materials is crucial to improve the performance of fuel cells and to boost their commercialisation. In this work, a series of bimetallic palladium alloy nanoparticles assembled on reduced graphene oxide, namely PdFe/rGO, PdAg/rGO and PdAu/rGO, was prepared and tested for oxygen reduction reaction (ORR) and borohydride oxidation reaction (BOR) in alkaline media. The morphology and structure of the as-prepared PdM alloy NPs and PdM/rGO electrocatalysts were characterised by XRD, TEM, XPS and ICP-MS and their electrochemical activity was investigated by cyclic and linear scan voltammetry, chronoamperometry, and rotating disc electrode measurements. Among the tested electrocatalysts, PdAu/rGO demonstrated the best performance by providing high current densities for both ORR and BOR. The number of electrons exchanged during ORR at PdAu/rGO, PdAg/rGO and PdFe/rGO electrocatalysts was calculated to be 4.0, 2.8 and 2.0, whereas Tafel slopes were evaluated to be 0.202, 0.182 and 0.173 V dec(-1), respectively. BOR at PdAu/rGO and PdFe/rGO proceeds with 5.5 and 2 electrons exchanged, respectively, and the reaction order ranged from 0.4 for PdAg/rGO to 1 for PdAu/rGO. Furthermore, effect of temperature was studied and BOR activation energy determined to be 23 kJ mol(-1). (C) 2017 Elsevier B.V. All rights reserved.