The chemical looping process, which utilizes oxygen carriers to split CO₂, is a promising approach for CO₂ conversion due to the much higher CO₂ conversion efficiency than photocatalytic and electrocatalytic process. Conventional oxygen carriers have to include a large content of inert support, typically Al₂O₃, to avoid sintering, thus leading to a trade-off between the reactivity and stability. Here, we propose the use of ion-conductive Gd-doped CeO₂ (GDC) to prepare the supported oxygen carriers. The resulting Fe₂O₃/GDC materials achieves both high reactivity and stability. Fe₂O₃/Gd_0.3Ce_1.7O_3-δ shows CO productivity of ~10.79 mmol.g^-1 and CO production rate of ~0.77 mmol.g^-1.min^-1 which is two-fold higher than that of Fe₂O₃/Al₂O₃. The performance remains even after 10 cycles. Mechanism study manifests the oxygen-ion diffusion constitutes of the rate-limiting step through the chemical looping reaction and the GDC materials significantly improve the outward oxygen diffusion at the reduction stage and the inward diffusion in the CO₂ splitting stage, which contributes to the enhanced CO₂ conversion behavior. The results in the current work provides a potentially viable way for designing the oxygen carriers by tuning the support properties.

CO2 conversion,Chemical looping,support effect,Oxygen-ion conductivity