Supported iron based redox systems for hydrogen production and storage from ethanol

Hydrogen production using ethanol and Fe2O3/support in a redox cycle was investigated. The composites were prepared by impregnation of Al2O3 and SiO2 with Fe(NO3)3, with different proportions of iron, i.e. 10, 30 and 50 wt.%, calcinated at 450 deg. C and characterized by Moessbauer spectroscopy, XRD, SEM, BET and TG. The redox cycle to produce and/or store hydrogen is a two step process (1) initially the ethanol is used to reduce the iron oxide to Feo; (2) and when H2 is needed, Feo reacts with H2O to produce CO-free hydrogen, and the iron oxide is reduced again to Feo making this system cyclic. After the reactions it was interesting to observe that ethanol can directly reduce the iron oxide to produce metallic iron, with carbon deposition and iron-carbon as side product. Preliminary results indicate that it is possible to perform multiple redox cycles with the supported iron oxide without deactivation.