Enhancement of sintering resistance is key to the application of iron-based oxygen carriers in chemical looping CO₂ conversion processes. This drives research to seek the origin of iron oxide sintering during redox cycling. Herein, we explored it by using a Fe₂O₃ material on a stable ZrO₂ support, based on a thermodynamic analysis and time-resolved in-situ X-ray diffraction characterization. Sintering of iron oxide particles originates from the formation of FeO as intermediate during reduction. A prolonged FeO presence leads to more severe sintering. Although quite counter-intuitive, increasing the reaction temperature can mitigate sintering as it shortens the transition time between FeO and Fe phases. These findings provide important insight for the rational design of iron-based oxygen carriers, as well as for the optimization of operating conditions to resist sintering in chemical looping processes.

增强耐烧结性是铁基氧载体在化学回路CO ₂转化过程中应用的关键。这推动了研究寻找氧化还原循环中氧化铁烧结的起源。在这里，我们通过在稳定的ZrO ₂上使用Fe ₂ O ₃材料来探索它。支持，基于热力学分析和时间分辨的原位X射线衍射表征。氧化铁颗粒的烧结源自还原过程中作为中间体的FeO的形成。长时间的FeO存在会导致更严重的烧结。尽管非常违反直觉，但是提高反应温度可以减轻烧结，因为它缩短了FeO和Fe相之间的转变时间。这些发现为合理设计铁基氧气载体以及优化操作条件以抵抗化学循环过程中的烧结提供了重要的见识。