Development of catalyst technologies for hydrogen production from
natural gas

@Hydrogen is expected to be used as an energy source for on-site fuel cells such as proton-exchange membrane (PEM) type, as well as a large-scale chemical industry. At present, hydrogen is typically produced via steam reforming (SR) and/or partial oxidations of hydrocarbons or alcohols and their combinations. In these cases, however, not only C0₂ but also CO is a co-product. Therefore, the fuel cells require complete elimination of CO (<1 ppm) in order to prevent poisoning of the Pt catalyst of the cells. An alternative route is to directly transform the hydrocarbons into hydrogen, benzene and carbon. In this case, no COx is formed and the need for subsequent reactions, such as water-gas shift and CO oxidation, is eliminated, although there is required an alternative removal processes of carbon product such as 1) a combustion of carbon by some oxidants (H₂0, C0₂ etc.), 2) a separation by centrifuge. We have already reported that carbon- and Ni/Ca/Carbon-based catalysts were effective for methane/ethane decomposition to form hydrogen over the range of 600- 1300 K. This article reviews, first, outline of steam-reforming and C0₂ reforming of methane over various solid oxide catalysts and, second, novel forthcoming processes of 1) transformation of methane into hydrogen, benzene, and 2) decomposition of methane to form hydrogen and carbon. And third further works for all these research subjects to be solved will be discussed.