In this work we investigate the electrooxidation of acetaldehyde in acidic media on platinum-ruthenium-rhodium electrodeposits of several compositions. Combined results of electrochemistry and in situ FfIR spectroscopy show that the Ru/Rh ratio plays a pivotal role on the electrooxidation of acetaldehyde on PtRuRh surfaces. The combination of these metals apparently establishes a delicate balance between the ability of a surface to oxidize adsorbed species and to promote the C-C bond breaking. Overall, by estimating the charges involved in each oxidation pathway we were able to mimic the electrochemical behavior as a function of the composition. The global output suggests that the proper combination of platinum-ruthenium-rhodium can lead to the development of active catalysts towards the oxidation of small organic molecules. (C) 2015 Elsevier B.V. All rights reserved.