Iron Oxide Cycle

The iron oxide cycle is the original two-step thermochemical cycle proposed for hydrogen production, based on the reduction and subsequent oxidation of iron ions, particularly the reduction and oxidation between the Fe3+ and Fe2+ states of iron oxide, or Fe3O4/FeO. The iron oxide, or ferrite, begins in the form of a spinel crystal structure, and depending on the reaction conditions and any dopant metals or support material used, it forms either wustite or a different spinel structure as the cycle proceeds.