Thermochimica Acta, Vol.400, No.1-2, 61-67, 2003
The mechanism of reduction of iron oxide by hydrogen
Precipitated iron oxide samples were characterized using temperature-programmed reduction. H-2 was used as the reduction agents. The two-stage reduction was observed: Fe2O3 was reduced to Fe3O4 and then reduced to metallic Fe. The activation energy for the two reduction steps of iron oxide are 89.13 and 70.412 (kJ mol(-1)), respectively. The simulation by reduction models of the TPR patterns presents well fitting of unimolecular model for Fe2O3 --> Fe3O4 reduction and two-dimensional nucleation according to Avarmi-Erofeev model for Fe3O4 --> Fe.