Increasing the capacity and kinetics of oxygen exchange in solid oxides is important to improve the performance of numerous energy-related materials, especially those for the solar-to-fuel technology. Dual-phase metal oxide composites of La_0.65Sr_0.35MnO₃–x%CeO₂, with x = 0, 5, 10, 20, 50, and 100, have been experimentally investigated for oxygen exchange and CO₂ splitting via thermochemical redox reactions. The prepared metal oxide powders were tested in a temperature range from 1000 to 1400 °C under isothermal and two-step cycling conditions relevant for solar thermochemical fuel production. We reveal synergetic oxygen exchange of the dual-phase composite La_0.65Sr_0.35MnO₃–CeO₂ compared to its individual components. The enhanced oxygen exchange in the composite has a beneficial effect on the rate of oxygen release and the total CO produced by CO₂ splitting, while it has an adverse effect on the maximum rate of CO evolution. Ex situ Raman and XRD analyses are used to shed light on the relative oxygen content during thermochemical cycling. Based on the relative oxygen content in both phases, we discuss possible mechanisms that can explain the observed behavior. Overall, the presented findings highlight the beneficial effects of dual-phase composites in enhancing the oxygen exchange capacity of redox materials for renewable fuel production.

中文翻译：

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用于太阳能热化学燃料生产的La0.65Sr0.35MnO3-CeO2双相复合材料中的氧交换。

提高固体氧化物中氧交换的容量和动力学对于提高许多与能源有关的材料的性能非常重要，特别是对于太阳能燃料技术而言。通过实验研究了La = _0.65 Sr _0.35 MnO ₃ – x％CeO ₂的双相金属氧化物复合物通过x = 0、5、10、20、50和100进行氧交换和CO ₂分解的过程。热化学氧化还原反应。在与太阳能热化学燃料生产相关的等温和两步循环条件下，在1000至1400°C的温度范围内对制得的金属氧化物粉末进行测试。我们揭示了双相复合La _0.65 Sr _0.35 MnO ₃ -CeO ₂与其单个组分相比的协同氧交换。复合材料中增强的氧交换对氧气释放速率和由CO ₂分解产生的总CO产生有利影响，而对最大CO释放速率则具有不利影响。异地拉曼和XRD分析用于阐明热化学循环过程中的相对氧含量。基于两个阶段的相对氧含量，我们讨论了可以解释观察到的行为的可能机理。总体而言，提出的发现突出了双相复合材料在增强氧化还原材料用于可再生燃料生产的氧交换能力方面的有益作用。