Improved steam-iron process

The use of promoted iron oxide catalysts for the production of pure hydrogen via an reduction-reoxidation cycle has been examined. The use of methane as a reductant and steam as an oxidant over an iron based catalyst promoted by ceria and ceria-zirconia has been studied. Iron oxide reduction by carbon based reductants is prone to coking and formation of iron carbide species. The promoter oxides were expected to promote the gasification of coke. In practise, minimal reduction by methane was observed up to a temperature of ca 750°C - a value at which methane decomposition is known to occur. No carbon deposition over the redox cycle was observed with the promoted catalyst. The higher temperatures favoured sintering, despite the stabilisation offered by the promoters.