Ethanol partial oxidation was studied on Co3O4/gamma-Al2O3/cordierite honeycomb structured catalyst. Honeycomb structure consists of parallel channels that favor the gas phase reactions, which in some temperature and flow rate conditions could be limited by mass transfer effects in gas phase. The catalytic activity and products selectivity were evaluated at different temperatures and O-2:ethanol ratios. Also, it evaluated the effect of space velocity (h(-1)) and presence of H2O in the feed. Overall, the results showed that the partial oxidation reaction occurs in a way that the ethanol is first decomposed in gas phase and then formed in the presence of oxygen radicals that decomposed on the catalyst surface. The CO2:CO low ratio observed in most experiments indicates that shift reaction occurs in gas phase and its equilibrium limits the hydrogen formation. Although this catalyst has not presented any significant deactivation, some carbon formation was observed after 30 h on reaction. (c) 2010 Elsevier B.V. All rights reserved.