A carbon nanotubes (CNTs) supported composite catalyst consisting of Pd and Ni (Pd-Ni/CNT) is synthesized by a chemical method. The electrocatalytic activities of Pd/CNT, Ni/CNT and Pd-Ni/CNT toward the hydrazine oxidation reaction (HOR) are evaluated by linear sweep voltammetry, electrochemical impedance spectroscopy and polarization measurement. The composite catalyst demonstrates higher electrocatalytic activity than its single-constituent catalysts due the synergy between Ni and Pd. The Pd addition in the composite catalyst prevents oxidation of Ni so that the Pd-Ni/CNT electrode exhibits smaller reaction resistance to the HOR than the Ni/CNT and Pd/CNT electrodes. (C) 2010 Elsevier B.V. All rights reserved.