Hydrogen and Carbon Monoxide Production by Chemical Looping over Iron‐Aluminium Oxides

H 2 and CO production from H 2 O and CO 2 is investigated experimentally using a two‐step chemical looping process based on the redox cycles of iron‐alumina mixed oxides. The reduction of Fe 3 O 4 in the first endothermic step is followed by the splitting of CO 2 or H 2 O in a second exothermic step. The iron‐aluminum oxides are more reactive with H 2 O than with CO 2 in the range 650–750 °C. In situ XRD shows that deactivation results from different processes: iron oxide sintering and the formation of spinel (FeAl 2 O 4 ) with a lower oxygen‐storage capacity. However, FeAl 2 O 4 assumes the role of Al 2 O 3 and mitigates the iron oxide sintering. Deactivation at 650 °C is governed predominantly by sintering, and the further loss of activity is caused by combined sintering and spinel formation. Spinel formation is more dominant at 750 °C. A mixed oxide of Fe 2 O 3 and Al 2 O 3 with a mass ratio of 70:30 was the most active and stable for H 2 O and CO 2 splitting in chemical looping.