The NO reduction with ethanol was studied on Pd/Al2O3 and Pd-Mo/Al2O3 catalysts. The Pd/Al2O3 catalyst was more active for NO conversion, although the selectivity for N-2 formation was the same on both catalysts. IR and TPD analysis of adsorbed ethanol showed formation of stable acetate species upon dehydrogenation of ethanol to acetaldehyde at reaction temperature. TPSR measurements suggested that NO preferentially adsorbs on Pd while ethanol selectively adsorbs on alumina and/or partially reduced molybdenum oxide (MoOx). The catalytic results further suggested that the reaction mechanism was the same on both catalysts and that the reaction occurred between adsorbed NO and acetate species at the metal/oxide interface. A reaction mechanism was proposed where the limiting step was the dehydrogenation of ethanol to acetaldehyde. (C) 2003 Elsevier Inc. All rights reserved.