Hydrogen production by catalytic decomposition of methane

The large reserves of natural gas could serve as a feedstock for the production of an alternative fuel. Hydrogen can play a decisive role in a future energy system when petroleum becomes scarce, expensive and unsuitable because of ecological reasons. Currently, hydrogen is being used in many industries. Hydrogen is mainly produced from natural gas by steam-reforming of methane which is an energy intensive process and requires further separation of hydrogen from synthesis gas. Hence, it is desirable to develop a simpler and less energy intensive method. The decomposition of methane over catalyst has recently been receiving attention as an alternative route to the production of hydrogen. It produces only H2 and solid carbon, thereby eliminating the necessity for the separation of H2 from COx. For fuelling the fuel cells, it is easier to use such methane-hydrogen containing mixture than to use synthesis gas which inhibits platinum electrodes, due to the CO content. Also, methane is more easily separated from hydrogen than COx. The carbon produced can be used as promising sorbents, catalyst supports, carbonaceous composite materials etc. Therefore, with this process, not only hydrogen is formed at low cost, but the carbon formed can also be a value added product. Furthermore, pure oxygen, which requires expensive cryogenic separation, is no longer required in this process. In this study, methane catalytic decomposition on various Ni-containing catalysts has been investigated as a method for the production of COx-free hydrogen for use in fuel cells. While different types of filamentous carbon form on the various Ni-containing catalysts, attractive nanocarbon tubes were observed on the Ni/Mn based catalyst. This type of carbon, coupled with stable activity of the catalyst and without requiring any pre-treatment of the catalyst before reaction, makes this an interesting conceptual process for hydrogen production for fuel cell applications