Hydrogen production by redox of bimetal cation-modified iron oxide

Abstract

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 °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 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%.