The performance of ethanol electro-oxidation on Pd thin films as a catalyst layer in direct ethanol fuel cells (DEFCs) can be promoted by co-electrodeposited Pd-Ni alloy thin films. The effect of ethanol electro-oxidation through the modulation of different parameters of electrodeposition such as potential and electric charge was investigated by different Pd-Ni composition in this study. In addition, complexing agents such as potassium thiocyanate (KSCN) and triethanolamine (TEA) were used to improve the defects of Pd-Ni alloy thin films compared with those fabricated in the absence of complexing reagents, and to promote further the maximum performance of ethanol electro-oxidation. Pd-Ni films with high Pd amount composition deposited with TEA were found to have the best function of complexity which possessed the best and maximum current density of Jp = 117.3 mA/cm(2) in ethanol electro-oxidation. In the meanwhile, the films produced with complexing agent TEA promote the performance of ethanol electro-oxidation even when the composition of Pd is less than 80%. (C) 2014 The Electrochemical Society. All rights reserved.