Hydrogen production from ethanol reforming over nickel catalysts supported on lanthanum loaded Al2O3 substrates was studied. Activity results revealed the enhancement in the reforming stability of the Ni catalysts with the increase in the lanthanum loading on Al2O3 substrates. Catalytic behavior of Ni/La-Al2O3 catalysts in the ethanol steam reforming was found to be the contribution of the activity of the La-Al2O3 supports for the ethanol dehydration reaction and the activity of the nickel metallic phase that catalyzes both dehydrogenation and C-C bond rupture. Physicochemical characterization of catalysts revealed that acidity, nickel dispersion and nickel-support interaction depend on the Laloading on Al2O3. The better reforming stability of catalysts with the increase in La content was explained in terms of the ability of nickel surface and/or La-Ni interactions to prevent the formation of carbon filaments. (c) 2007 Elsevier B.V. All rights reserved.