Steam reforming of ethanol over nickel molybdenum carbides for hydrogen production

The steam reforming of ethanol over carburized NiMo catalysts was studied to determine the effects of the Ni content, carburization temperature in 20% CH4/H-2, GHSV, potassium addition and a comparison of the reduced catalyst. The catalysts were characterized by CO adsorption, XRD, X-ray electron spectroscopy (XPS) and temperature-programmed surface reaction after ethanol adsorption. The 798 K-carburized NiMo catalyst gradually increased below 500 min and it exhibited a higher activity than the reduced NiMo catalyst. The addition of potassium promoted more hydrogen selectivity than the nonpotassium-added catalysts. The 798 K-carburized catalyst exhibited the high intensity peaks of MoO2 and small peaks Of beta-Mo2C and Ni metal (or NiMo) were present, while the 823 K-carburized catalyst showed broad and small peaks. The 873 and 848 K-carburized catalysts contained a strong intensity of beta-Mo2C and clear Ni metal (or NiMo). The XPS measurements revealed that the hydrogen production was proportional to Ni-0 of the carburized NiMo catalyst. The addition of potassium significantly increases the Ni-0 ratio, which was stabilized instead of increasing the Mo oxidation during the reaction. (C) 2009 Elsevier B.V. All rights reserved.