Hydrogen production by redox of bimetal cation-modified iron oxide

Pure hydrogen can be stored and supplied directly to polymer electrolyte fuel cell by the redox of iron oxide: Fe3O4 + 4H2 → 3Fe + 4H2O and 4H2O + 3Fe → Fe3O4 + 4H2. Four bimetal-modified samples were prepared by impregnation. The hydrogen storage properties of the samples were investigated. The result shows that the Fe2O3-Mo-Al sample presented the most excellent catalytic activity and cyclic stability. H2 forming temperature and H2 forming rate could be surprisingly decreased and enhanced, respectively. The average H2 forming temperature at the rate of 250 μmol min−1·Fe-g−1 for Fe2O3-Mo-Al in the first 4 cycles could be decreased from 469 °C before the addition of Mo-Al to 273 °C after the addition of Mo-Al. The reason for it may be that the Mo-Al additive in the sample can prevent from the sintering of the particles and accelerate the H2O decomposition due to Mo taking part in the redox reaction. The average storage capacity of Fe2O3-Mo-Al was up to 4.68 wt%.