▎ 摘　　要

The graphene supported precious metal nanocrystal composites have attracted tremendous attention in the field of catalysis/electrocatalysis. In this work, we demonstrate a facile co-chemical reduction approach for the synthesis of the reduced graphene oxide (RGO) supported Pt-Cu alloy nanocrystal (Pt-Cu/RGO) composites. The electrostatic interaction between graphene oxide (GO) and polyallylamine-metal complex plays a critical role in determining the dispersibility of the Pt-Cu nanocrystals on the RGO surface. Various physical characterizations show the bimetallic Pt-Cu nanocrystals are highly alloying, and monodispersed Pt-Cu alloy nanocrystals with 6 nm size are uniformly distributed on the RGO surface. Electrochemical measurements show the as-prepared Pt-Cu/RGO composites have superior electrocatalytic activity and stability towards the ethanol oxidation reaction compared to commercial Pt/C electrocatalyst. (C) 2015 Elsevier Ltd. All rights reserved.