Iron-based materials are extensively employed as oxygen carriers in chemical looping processes, but their long-term performance is often inhibited by sintering and agglomeration. Here, we developed a yolk–shell structured FeO@YO oxygen carrier, with each unit consisting of a YO shell encapsulating a nano-sized FeO core. The YO shell could protect the redox-active cores from sintering, and the void between the yolk and the shell is capable of tolerating cyclic volume and phase changes. During the simulated chemical looping cycles at 600 °C, the FeO@YO oxygen carriers exhibit a consistent oxygen carrying capacity of 3 wt% over 50 cycles, without any distinguishable structural deterioration. With rational structure optimization, the FeO@YO oxygen carriers with porous shell could enhance the mass transfer across the shell and enable higher reaction rates. The satisfactory sintering resistance of the FeO@YO nanostructure demonstrates the feasibility of employing well defined yolk–shell structured oxygen carriers for chemical looping applications.

中文翻译：

---

作为化学链氧载体的均匀 Fe2O3@Y2O3 蛋黄壳纳米反应器的合成

铁基材料广泛用作化学循环过程中的氧载体，但其长期性能常常受到烧结和团聚的抑制。在这里，我们开发了一种蛋黄壳结构的 Fe3O@YO 氧载体，每个单元都由包裹着纳米尺寸 Fe3O 核的 YO2 壳组成。 YO壳可以保护氧化还原活性核免于烧结，蛋黄和壳之间的空隙能够承受循环体积和相变。在 600 °C 的模拟化学循环循环中，FeO@YO 氧载体在 50 个循环中表现出 3 wt% 的一致载氧能力，没有任何明显的结构恶化。通过合理的结构优化，具有多孔壳的FeO@YO氧载体可以增强穿过壳的传质并实现更高的反应速率。 FeO@YO纳米结构令人满意的耐烧结性证明了采用明确的蛋黄壳结构氧载体进行化学循环应用的可行性。