The TPR patterns (Figure ) show two distinct peaks. The catalysts with higher iron loading of 5 wt% and 10 wt% show peaks at about 400 °C and between 630 and 700 °C. The first peak indicates the reduction of Fe2O3 to Fe3O4. Fe3O4 is further reduced to Fe 0 at the second peak. The peak intensities correlate with the hydrogen consumption for each reduction step and the iron loading. For supported catalysts, the interaction between the metal particles and the support at high temperatures is reported. The peak shoulder at about 800 °C indicates the formation of iron aluminates. The peaks are shifted for the catalyst with 1 wt% iron loading. The reduction of Fe2O3