In chemical looping combustion, iron-based oxygen carriers often experienced serious phase segregation, which reduced the cyclic stability of the oxygen carriers. In this work, Fe₂O₃/Al₂O₃ (FA) was doped with different metals (Sr, La and Ce) to improve the redox performance during cyclic reactions. The mechanism of dopants on FA was explored by experimental research and characterization analysis. The promotion effect of different dopants on the redox performance of FA followed the sequence: Sr > La > Ce. It was shown that the deactivation of Ce-FA and La-FA was obvious in 20 cycles. The results of 100 successive cycles indicated that the surface structure of Sr-FA remained stable and no sintering was observed. The Sr-FA achieved stable oxygen carrying capacity (4%) in 100 redox cycles. The characterization results indicated that the addition of Sr could effectively increase the concentration of oxygen vacancies, thus inhibiting the phase segregation of FA. The enrichment degree of surface Fe of FA, Sr-FA, La-FA and Ce-FA were 135.7%, 43.47%, 128.0% and 140.0%, respectively. The results of this study provide guidance for the preparation of iron-based oxygen carriers with high redox performance.

在化学循环燃烧中，铁基氧载体经常发生严重的相偏析，降低了氧载体的循环稳定性。在这项工作中，Fe ₂ O ₃ /Al ₂ O ₃(FA) 掺杂不同的金属 (Sr、La 和 Ce) 以提高循环反应过程中的氧化还原性能。通过实验研究和表征分析探索了掺杂剂对 FA 的作用机制。不同掺杂剂对FA氧化还原性能的促进作用顺序为：Sr>La>Ce。结果表明，Ce-FA 和 La-FA 在 20 个循环后失活明显。100 个连续循环的结果表明 Sr-FA 的表面结构保持稳定，没有观察到烧结。Sr-FA 在 100 次氧化还原循环中实现了稳定的携氧能力 (4%)。表征结果表明，Sr的加入可以有效增加氧空位的浓度，从而抑制FA的相分离。FA、Sr-FA的表面Fe富集度，La-FA 和 Ce-FA 分别为 135.7%、43.47%、128.0% 和 140.0%。该研究结果为制备具有高氧化还原性能的铁基氧载体提供了指导。