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Ethanol steam reforming was studied over Ni/MgAl 2 O 4 -CeO 2 catalysts. The catalysts were prepared using different impregnation media (ethanol or water) and Ni precursors (nitrate or acetate). The use of an alcoholic solution did not affect the specific surface area, but promoted the NiO formation reducible at lower temperature affecting the Ni-support interactions and the Ce 3+ /Ce 4+ initial ratios. All catalysts were highly active in the reforming reaction of ethanol with a high initial conversion of ethanol under more severe conditions than those commonly used in literature. The best catalytic behavior was found over the catalyst prepared from an ethanolic solution of Ni(NO 3 ) 2 . This sample showed a high Ce 3+ /Ce 4+ ratio, an adequate interaction Ni-support and an average Ni diameter around 28 nm. This catalyst was stable under the reforming conditions used in this work: initial ethanol concentration: 9.4%, reaction temperature: 650 °C, W/F = 49 g min mol −1 C 2 H 5 OH and reaction time: 40 h. The ethanol conversion was almost complete with H 2 selectivity around 78%.

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MgAl 2 O 4 spinel employed as support of reforming catalysts was doped by CeO 2 . The samples were prepared by wet impregnation from aqueous solutions of cerium nitrate, with and without chelating agents. The chelating agents used were ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA) and citric acid (CA) at different pH of impregnation. The solids were characterized by TG, XRD, S BET , TPR, SEM-EDX and CO 2 −TPD. Nanoparticles of CeO 2 between 5 and 6.8 nm were obtained by the thermal decomposition in air at 600 °C. The surface cerium reduction occurred in a wide temperature range of 450° to 670 °C. The use of citric acid at pH= 8 led to the lowest crystallite size of CeO 2 and the lowest interaction with the spinel. The H 2 consumption and extent of CeO 2 -support interaction did not show a clear dependence with the CeO 2 crystallite sizes. The use of chelating agents in the impregnation step did not modify the total basicity. Slight changes in the strength of weak basic sites were observed.