The electrocatalytic oxidation of hydrazine was studied over Ni, Cu, Co and Ni-based ternary alloy on graphite electrodes in alkaline solution. The catalysts were prepared by cycling the graphite electrode in solutions containing Ni, Cu and Co ions at cathodic potentials. The synergistic effects and the catalytic activity of the modified electrodes were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). It was found that, in the presence of hydrazine, the modified Ni-based ternary alloy electrode (G/NiCuCo) exhibited a good catalytic activity for the oxidation of hydrazine at a reduced overpotential and it has a significant high response for hydrazine oxidation. During CA regime the reaction follows a Cottrellin behavior and the diffusion coefficient of hydrazine is found to be 628 x 10(-6) cm(2) s(-1). EIS studies were used to investigate the, catalytic oxidation of hydrazine on the surface of the modified electrode. (C) 2015 Elsevier B.V. All rights reserved.