Bork Alexander H, Carrillo Alfonso J, Hood Zachary D, Yildiz Bilge, Rupp Jennifer L M
Electrochemical Materials Laboratory, Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Laboratory for Electrochemical Interfaces, Department of Materials Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
ACS Appl Mater Interfaces. 2020 Jul 22;12(29):32622-32632. doi: 10.1021/acsami.0c04276. Epub 2020 Jul 7.
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 LaSrMnO-%CeO, with = 0, 5, 10, 20, 50, and 100, have been experimentally investigated for oxygen exchange and CO splitting 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 LaSrMnO-CeO 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 CO splitting, while it has an adverse effect on the maximum rate of CO evolution. 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.
提高固体氧化物中氧交换的容量和动力学对于改善众多与能源相关材料的性能至关重要，特别是对于太阳能到燃料技术的材料。对LaSrMnO-%CeO（其中= 0、5、10、20、50和100）的双相金属氧化物复合材料进行了氧交换和CO分解热化学氧化还原反应的实验研究。制备的金属氧化物粉末在1000至1400°C的温度范围内，在与太阳能热化学燃料生产相关的等温及两步循环条件下进行了测试。我们揭示了双相复合材料LaSrMnO-CeO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释放速率和CO分解产生的总CO有有益影响，而对CO逸出的最大速率有不利影响。拉曼和XRD分析用于阐明热化学循环过程中的相对氧含量。基于两相中的相对氧含量，我们讨论了可以解释观察到的行为的可能机制。总体而言，所呈现的研究结果突出了双相复合材料在提高用于可再生燃料生产的氧化还原材料的氧交换能力方面的有益作用。
