The development of stable and performant oxygen carriers (OC) remains a bottleneck in upscaling of chemical looping processes. Iron oxides are often applied because of their low cost, high mechanical strength and low toxicity. Moreover, they provide a high oxygen storage capacity (1.3 mol CO2/mol Fe) in a wide operating window of temperatures. Fe3O4 as such deactivates quickly, so iron oxides require a supporting material to delay sintering, which originates from FeO formation during reduction. Among possible supports, MgAl2O4 proves interesting as Fe2O3/MgAl2O4 combinations provide high reactivity and limited deactivation. Comparison between lab-scale material and semi-industrially produced OC showed that the synthesis can be upscaled without significant loss in performance. Here, the chemical and mechanical stability of 50 wt% Fe2O3/MgAl2O4 extrudates are investigated during the chemical looping reverse water-gas shift (CL-rWGS) process. X-ray tomography is applied to study the microstructural evolution of Fe-based OCs after redox cycles. Results indicate that redox cycling causes a redistribution of the metal phase and porosity, initiating chemical and mechanical degradation. Secondly, the impact of temperature and active gas concentration on the stability of the OC is determined during CL-rWGS experiments at lab-scale. Elevated active gas concentrations and temperatures lead to increased cumulative specific CO yields, but accelerated deactivation because of Fe inclusion into a FeAl2O4-like spinel and sintering of FeAl2O4 and MgAl2O4 phases. Finally, OCs are applied during pilot-scale experiments, after which characterization is performed for comparison with our newly acquired lab-scale results.