▎ 摘　　要

Hollow hemisphere-shaped macroporous graphene/tungsten carbide/platinum (HMG/WC/Pt) nano composite has been synthesized as an efficient electrocatalyst for the oxygen reduction reaction (ORR). The HMG/WC/Pt sample has been systematically characterized by the X-ray diffraction (XRD), Scanning electron microscope (SEM) and Transmission electron microscopy (TEM). The analysis results indicate that the sample has an interesting three-dimensional hollow hemisphere-shaped macroporous architecture. The results also demonstrate the successful integration of WC and Pt nanoparticles on the HMG, in which the WC nanoparticles are in size of about 10 nm and the Pt nanoparticles are in size of about 3 nm. The as-prepared HMG/WC/Pt electrode displays excellent electrocatalytic performances for the ORR in 0.1 mol L-1 HCIO4 electrolyte. The mass activity (i(m) at 0.9 V) of HMG/WC/Pt is 206 mA mg(-1) Pt, which is about 85% higher than that of Pt/C (112 mAmg(-1)Pt). It also displayed a very high activity retention of 84.5% after 2000 cyclic voltammetry cycles for the HMG/WC/pt, while that of the Pt/C is only 70.5%. The HMG/WC/Pt nanocomposite would be a promising electrocatalytic material for the ORR in Fuel cell applications. (C) 2016 Elsevier Ltd. All rights reserved.