In this work, Pt-based nanoparticles with Ni and Co on carbon support were prepared and used as electrocatalysts in the oxidation reactions of ethanol and acetaldehyde in alkaline solution. The nanoparticles were prepared by chemical reduction with sodium borohydride and characterized by means of energy dispersive X-ray spectroscopy, X-ray powder diffraction, and transmission electron microscopy. The catalytic activity was determined from cyclic voltammetry and chronoamperometry measurements. Our results indicate that in our Pt-based catalysts, the presence of Ni promotes the initial steps of the oxidation process, while Co promotes later steps involving acetyl species. The catalytic behavior of the materials can be understood when considering factors as chemical composition and alloy degree in the prepared nanoalloys. (C) 2017 Elsevier Ltd. All rights reserved.