Collaborative Research: Elucidating the Roles of Electric Fields Within Mixed Ionic and Electronic Conducting Oxides Under Electrochemical Reducing Conditions

非技术描述：高温电化学装置是新型高效能量转换系统所需的关键元件。例如，固体氧化物电解池可以通过蒸汽电解提供氢气。或者，如本工作中所设想的，这种系统还可以从蒸汽和二氧化碳提供合成气（一氧化碳和氢气）。这种复杂的系统以高效率运行，并且可以使用从间歇性电源获得的电力。然而，它们的性能需要适当的优化以避免降级。最近的工作表明，混合离子-电子导电氧化物基阴极表现出有前途的活性和稳定性，这有利于在进料中使用纯二氧化碳。然而，对这些氧化物如何处理二氧化碳的基本理解仍然有限。在这个项目中，PI Nikolla和麦克尤恩将实验和理论相结合，以确定混合离子电子导电陶瓷材料如何与二氧化碳相互作用，以促进其加工。正在开发用于在固体氧化物电解池环境中识别鲁棒（活性和稳定）氧化物阴极的设计标准。PIs Nikolla和麦克尤恩还通过培训研究生和本科生积极参与外联活动，这些学生通常在工业或学术界找到工作。研究团队还通过与丰田研究中心的互动与行业合作。因此，本研究使学生接触到工业研究环境，并使他们能够看到学术界的基础工作和工业应用之间的联系。技术优势：实验和理论技术相结合，以发展对混合离子电子导电（MIEC）氧化物上的CO2电化学还原的基本理解。这种基本的理解，然后使设计标准，用于识别鲁棒（活性和稳定）的氧化物作为固体氧化物电解池（SOEC）阴极被定义。SOEC是高温固态电解槽，其特征在于高效率和独特的可扩展性。在这个项目中，在氧化物层中的异质性，改变其表面的局部电场和SOEC的性能相关，检查和MIEC氧化物的还原性的组合物的效果被阐明。这方面的知识被用来定义强大的MIEC阴极SOEC的设计标准。加强下一代学生教育的活动，包括两组学生之间的夏季研究交流计划，以及与丰田研究中心的合作伙伴关系，使学生接触到工业研究环境，并提供学术界的基础工作和工业应用之间的联系，确保该项目的广泛影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: High temperature electrochemical devices are critical elements needed for new high efficiency energy conversion systems. For example, a solid oxide electrolysis cell can provide hydrogen via steam electrolysis. Alternatively, as envisioned in this work, such a system can also provide syngas (carbon monoxide and hydrogen) from steam and carbon dioxide. Such complex systems operate with high efficiency and can use electricity obtained from intermittent power sources. However, their performance requires proper optimization to avoid degradation. Recent work has shown that mixed ionic-electronic conducting oxide-based cathodes exhibit promising activity and stability, which facilitates the use of pure carbon dioxide in the feed. However, a fundamental understanding of how these oxides work for processing of carbon dioxide is still limited. In this project, PIs Nikolla and McEwen integrate experiments and theory to determine how a mixed ionic-electronic conducting ceramic material interacts with carbon dioxide to facilitate its processing. Design criteria for identification of robust (active and stable) oxide cathodes in a solid oxide electrolysis cell environment are being developed. PIs Nikolla and McEwen are also actively engaged in outreach activities through training graduate and undergraduate students, who typically find employment in industry or academia. The research team also partners with industry by interacting with the Toyota Research Center. As such, this research exposes students to an industrial research environment and enables them to see the link between fundamental work in academia and application in industry.TECHNICAL DETAILS: Experimental and theoretical techniques are combined to develop a fundamental understanding of the electrochemical reduction of CO2 on mixed ionic-electronic conducting (MIEC) oxides. This fundamental understanding then enables design criteria for identification of robust (active and stable) oxides as solid oxide electrolysis cell (SOEC) cathodes to be defined. SOECs are high temperature, solid-state electrolyzers characterized by high efficiencies and unique scalability. In this project, the heterogeneities in an oxide layer, which alter the local electric field at its surface and correlate to the performance of a SOEC, are examined and the effect of the composition on the reducibility of MIEC oxides is elucidated. This knowledge is used to define the design criteria for robust MIEC-cathode SOECs. Activities that enhance the education of the next generation of students, including a summer research exchange program among the two groups for students, and partnerships with the Toyota Research Center that expose students to an industrial research environment and provide a link between the fundamental work in academia and application in industry, ensure the broad impacts of this project.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.