CeO2 modified Fe2O3 for the chemical hydrogen storage and production via cyclic water splitting

The chemical hydrogen storage (hydrogen reduction) and production (water splitting) behaviour of Ce-modified Fe2O3 mixed oxides were investigated. Fe1-xCexO2-delta (x = 0, 0.05, 0.1, 0.2, 0.3, 0.4 and 1) oxides prepared by chemical precipitation were characterized by XRD (X-ray diffraction), H-2-TPR (hydrogen temperature-programmed reduction) and H2O-TPO (steam temperature-programmed oxidation) tests. XRD results showed that two kinds of Fe -Ce-O solid solutions (Ce-based and Fe-based) coexisted in Fe-Ce mixed oxides. H-2-TPR experiment suggested that Ce addition could reduce hydrogen reduction temperature while H2O-TPO experiments over reduced oxides showed that Fe-Ce mixed oxides could split water to produce hydrogen at a lower temperature and complete in a shorter time. Both redox reactions (hydrogen reduction and water splitting) were sensitive to the temperature and active at a high temperature. The successive redox cycles were carried out over the Fe0.7Ce0 3O2-delta mixed oxide at 750 degrees C. It kept a stable production of hydrogen in the successive redox process at the condition of serious agglomeration of the materials. The highest hydrogen storage amount was up to 1.51 wt% for the Fe-Ce sample with a 30% substitution of Ce for Fe. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.