Facile synthesis of carboxylated-graphene nanosheets supported PtRu catalysts and their electrocatalytic oxidation of methanol

In this paper, we prove an efficient and facile synthesis method for preparing PtRu nanoparticles (NPs)/graphene nanosheets (GNS) catalysts for methanol electrooxidation. Our approach employed carboxylated-graphene nanosheets (C-GNS) as the support which prepared by the Friedel-Crafts reaction between succinic anhydride and GNS. The reaction conditions are mild without cumbersome pretreatment of GNS. The morphology and component of PtRu NPs/C-GNS catalysts were characterized by transmission electron microscopy (TEM) and inductively coupled plasma-atom emission spectroscopy (ICP-AES), respectively. The TEM observation reveals that PtRu NPs with an average diameter of ca. 4.0 +/- 0.5 nm uniformly distributed on the edges and wrinkles of C-GNS. The further electrochemical characterizations including cyclic voltammograms (CV) and chronoamperometry (CA) methods show that PtRu NPs/C-GNS catalysts have significantly higher electrocatalytic activity and stability toward methanol electrooxidation compared to the PtRu catalysts supported on the unmodified GNS. This provides an easy approach to synthesize GNS-based electrode materials for high-performance energy conversion devices in the future.