Hydrogen production by ethanol reforming over NiZnAl catalysts -: Influence of Ce addition on carbon deposition

Catalytic systems based on Ni supported on ZnAl2O4 spinel phase modified by CeO2 were prepared by a sol-gel method and characterized by different techniques such as thermal gravimetry (TG), BET, temperature-programmed reduction (TPR), NH3 DTP, X-ray diffraction (XRD), SEM, TPO and Raman spectroscopy. The ethanol steam reforming reaction was studied at atmospheric pressure in the temperature range 400-700 degrees C. The coke deposition depended strongly on the reaction temperature and the Ce/Ni ratio. The catalyst with 10% ceria exhibited interesting catalytic properties regarding carbon deposition. At 500 degrees C the presence of Ce slightly modified the product distribution but inhibited the filament formation. When the reaction temperature was high (700 degrees C) the catalytic performance was similar in catalysts with and without Cc and hydrogen selectivity was about 90%. (C) 2008 Elsevier B.V. All rights reserved.