Hydrogen Production By Redox Of Bimetal Cation-modified Iron Oxide

摘要

Pure hydrogen can be stored and supplied directly to polymer electrolyte fuel cell by the redox of iron oxide: Fe_3O_4 + 4H_2 → 3Fe + 4H_2O and 4H_2O + 3Fe → Fe_3O_4 + 4H_2. Four bimetal-modified samples were prepared by impregnation. The hydrogen storage properties of the samples were investigated. The result shows that the Fe_2O_3-Mo-Al sample presented the most excellent catalytic activity and cyclic stability. H_2 forming temperature and H_2 forming rate could be surprisingly decreased and enhanced, respectively. The average H_2 forming temperature at the rate of 250 μmol min~(-1)·Fe-g~(-1) for Fe_2O_3-Mo-Al in the first 4 cycles could be decreased from 469 ℃ before the addition of Mo-Al to 273 ℃ 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 H_2O decomposition due to Mo taking part in the redox reaction. The average storage capacity of Fe_2O_3-Mo-Al was up to 4.68 wt%.