▎ 摘　　要

In this study, different core@shell nanoparticles such as Ni@Pt, Ni@Pd and Ni@Ru on reduced graphene oxide (rGO) were synthesized using a two-step successive reduction method with sodium borohydride and ethylene glycol as reducing agents. The obtained electrocatalysts were characterized using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The hydrazine oxidation on Ni@Pt/rGO, Ni@Pd/rGO and Ni@Ru/rGO electrocatalysts was studied in a three electrode set-up. The results showed that the hydrazine oxidation current density on Ni@Pd/rGO (19722 A g(-1)) is 1.31 and 3.21 times higher than those of Ni@Pt/rGO (15030 A g(-1)) and Ni@Ru/rGO (6140 A g(-1)), respectively. The activation energy for hydrazine oxidation on Ni@Pd/rGO (7.1 kJ mol(-1)) is lower than that on Ni@Pt/rGO (14.2 kJ mol(-1)) and Ni@Ru/rGO (28.4 kJ mol(-1)). Also, the influence of Ni@Pt/rGO, Ni@Pd/rGO and Ni@Ru/rGO as an anodic electrocatalyst on the performance of direct hydrazine-hydrogen peroxide fuel cells (DHHPFCs) was investigated. The single fuel cell results showed that Ni@Pd/rGO resulted in an improvement in power density (204.79 mW cm(-2)) equal to 10.03% and 47.32% with respect to Ni@Pt/rGO (186.12 mW cm(-2)) and Ni@Ru/rGO (139.01 mW cm(-2)), respectively.