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

非技术描述：高温电化学设备是新的高效能量转换系统所需的关键元件。例如，固体氧化物电解槽可以通过蒸汽电解提供氢气。或者，正如这项工作所设想的那样，这样的系统也可以从蒸汽和二氧化碳中提供合成气(一氧化碳和氢气)。这种复杂的系统运行效率很高，可以使用从间歇电源获得的电力。然而，它们的性能需要适当的优化，以避免降级。最近的研究表明，离子-电子混合导电氧化物基阴极具有良好的活性和稳定性，有利于在原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了解仍然有限。在这个项目中，PI Nikolla和McEwen结合实验和理论来确定混合离子-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。正在制定在固体氧化物电解槽环境中识别坚固(活性和稳定)氧化物阴极的设计标准。PiS Nikolla和McEwen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业界合作。因此，这项研究使学生接触到工业研究环境，并使他们能够看到学术基础工作和工业应用之间的联系。技术细节：实验和理论技术相结合，以加深对混合离子-电子导电(MIEC)氧化物上二氧化碳电化学还原的基本理解。这一基本认识使我们能够确定用于确定作为固体氧化物电解槽(SOEC)阴极的坚固(活性和稳定)氧化物的设计标准。SOEC是一种高温固态电解槽，具有高效率和独特的可扩展性。在这个项目中，研究了氧化层中的异质性，它改变了氧化层表面的局部电场，并与SOEC的性能相关，并阐明了组成对MIEC氧化物还原能力的影响。这些知识被用来定义坚固的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暑期研究交流计划，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，并在学术基础工作和工业应用之间提供联系，确保了该项目的广泛影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.