Au-Co alloys supported on Vulcan XC-72R carbon were prepared by the reverse microemulsion method and used as the anode electrocatalyst for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties were investigated by energy dispersive X-ray (EDX), X-ray diffraction (XRD), cyclic voltammetry, chronamperometry and chronopotentiometry. The results show that supported Au-Co alloys catalysts have higher catalytic activity for the direct oxidation of BH(4)(-) than pure nanosized Au catalyst, especially the Au(45)Co(55)/C catalyst presents the highest catalytic activity among all as-prepared Au-Co alloys, and the DBHFC using the Au(45)Co(55)/C as anode electrocatalyst shows as high as 66.5 mW cm(-2) power density at a discharge current density of 85 mA cm(-2) at 25 degrees C. (c) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.