CO_x-Free Hydrogen and Carbon Nanofibers Produced from Direct Decomposition of Methane on Nickel-Based Catalysts

摘要

Direct decomposition of methane was carried out using a fixed-bed reactor at 700℃ for the production of CO_x-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO_2 catalysts (where M = AgO, CoO, CuO, FeO, MnO_x and MoO) in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO_2 promoted with CuO give the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al_2O_3, CeO_2, La_2O_3, SiO_2, and TiO_2, shows that the decomposition of methane over NiO-CuO favors SiO_2 support. Furthermore, the optimum ratio of NiO to CuO on SiO_2 support for methane decomposition was determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8:2 (w/w) since the highest yield of hydrogen was obtained over this catalyst.