Thermo catalytic decomposition of methane over Ni-Mg and Ni-Cu-Mg catalysts Effect of catalyst preparation method

• Published in: Applied catalysis. A, General General, 2007-12, Vol.333 (2), p.229-237
• Main Authors: ECHEGOYEN, Y, SUELVES, I, LAZARO, M. J, SANJUAN, M. L, MOLINER, R
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2007.09.012

Catalytic decomposition of methane is a potential alternative route for the production of hydrogen from natural gas. In the present paper we report the results of hydrogen production in the TCD of methane over Ni-Mg and Ni-Cu-Mg catalysts prepared by co-precipitation, impregnation and fusion methods. The characterization of the catalysts used and the carbon obtained is also presented. Whatever to be the preparation method, all the catalysts show a high and almost constant methane decomposition rate without deactivation after 8h on stream. The presence of copper enhances hydrogen production and the best results were obtained for Ni-Cu-Mg catalysts prepared by the fusion method, reaching a hydrogen production of 80vol.%. For the Ni-Mg catalysts, the nickel crystal size influences on the catalysts performance so that the highest the crystallite size the lowest the hydrogen yields. In contrast, for the Ni-Cu-Mg catalyst the Ni particle size has not a significant influence on the hydrogen yields. All catalysts tested promote formation of filamentous carbon some micrometers long and with a fiber diameter highly dependent on the presence of Cu: Ni-Mg catalysts promote the formation of fibers with homogeneous diameter around 30nm while Ni-Cu-Mg catalysts lead to the formation of fibers of inhomogeneous and bigger diameter.