It is well known that CO depletion from the hydrogen is compulsory in order to avoid the poisoning of the anode electrocatalyst of the PEM fuel cell. Hydrogen generated by ethanol reforming contains CO and acetaldehyde. The latter can be decomposed on the electrocatalyst generating more CO. The decarbonylation and methanation reactions are proposed by this work in order to eliminate acetaldehyde and CO from the hydrogen stream. Our results show that Ru/Al2O3 is more active than Ni/SiO2 for the methanation reaction. These catalysts also promote the decarbonylation of acetaldehyde generating methane and CO, with Ni/SiO2 being much more active than the Ru. catalyst. The performance of a double-bed reactor in the purification of hydrogen generated by ethanol reforming is described in this contribution. The first layer composed of Ni/SiO2 decomposes acetaldehyde producing methane and CO, which is then eliminated by the methanation reaction employing RU/Al2O3 in the second layer. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.