Hydrogen production by ethanol steam reforming over Cu-Ni/SBA-15 supported catalysts prepared by direct synthesis and impregnation

Cu-Ni/SBA- 15 supported catalysts prepared by the incipient wetness impregnation method were tested in the ethanol steam reforming reaction for hydrogen production. The effect of reaction temperature and metal loading was studied in order to maximize the hydrogen selectivity and the CO2/(CO + CO2) molar ratio. The best catalytic performance was achieved at 600 degrees C. Products distribution was the result of the combined effects of metal particles size, metal content and Ni/Cu ratio on the catalyst. In addition, two catalysts were prepared by the method of direct insertion of Ni and Cu in the initial stage of the SBA-15 synthesis. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), N-2-adsorption and inductively coupled plasma atomic emission spectroscopy (ICP-AES) results evidenced that SBA- 15 materials with long range hexagonal ordering were successfully synthesized in the presence of copper and nickel salts with the (Cu + Ni) contents around 4-6 wt.%. However, lower hydrogen selectivity as well as ethanol and water conversions were obtained with catalysts prepared by direct synthesis in comparison with those prepared by incipient wetness impregnation method. Particularly, the best catalytic results were achieved with a sample impregnated with 2 and 7 wt.% of copper and nickel, respectively. (c) 2007 Elsevier B.V. All rights reserved.