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

Abstract

Hydrogen production using ethanol and Fe 2 O 3 /support in a redox cycle was investigated. The composites were prepared by impregnation of Al 2 O 3 and SiO 2 with Fe(NO 3 ) 3 , with different proportions of iron, i.e. 10, 30 and 50 wt.%, calcinated at 450 • C and characterized by Mössbauer 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 Fe • ; (2) and when H 2 is needed, Fe • reacts with H 2 O to produce CO-free hydrogen, and the iron oxide is reduced again to Fe • 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.