In this study the AuCu/GR catalysts with different Au:Cu molar ratios were prepared by microwave heating of Au(III) and Cu(II) salts in ethylene glycol (EG) solutions at 150 degrees C for 30 min. It has been determined that the composition of AuCu/GR depends on pH of the reaction mixture. When the reaction mixture pH was 7.0, 10.1 and 12.2, the AuCu/GR catalysts with the Au: Cu molar ratios equal to 37: 1, 1: 13 and 1: 32, respectively, were synthesized. The structure and composition of the prepared catalysts were examined by XRD and ICP-OES. The shape and size of catalyst particles were determined by TEM. It has been found that the graphene supported AuCu catalysts with the Au: Cu molar ratios equal to 1: 13 and 1: 32 show an enhanced electrocatalytic activity toward the oxidation of BH4- ions compared with those of the bare Au/GR and Cu/GR catalysts. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem. org. All rights reserved.