Porous Co3O4 nanowire array has been in-situ grown on the La0.8Sr0.2MnO3-delta (LSM) electrode by a facile hydrothermal process aiming at enhancing the electrochemical performance of LSM anode for steam electrolysis in intermediate temperature proton-conducting solid oxide electrolyzer. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques have been employed to characterize phase structure, morphology and composition of the obtained hybrid. The high activity of the Co3O4 nanoarray improves the oxygen reduction performance of LSM at intermediate temperature. Significant improvement has been obtained in terms of catalytic activity of the hybrid electrode compared with bare LSM electrode in air. The maximum current efficiency of the hybrid electrode reaches 71.64% for steam electrolysis in a proton-conducting solid oxide electrolyzer at 700 degrees C, which is approximately 1.3 times higher than that for the bare LSM electrode. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.