Collaborative Research:Advancing strategies for in-situ determination and spatial mapping of components within membrane systems for energy conversion

电化学系统，如燃料电池和电解槽，在电动汽车和可再生能源转换系统的发展中起着核心作用，最近对特种化学品合成产生了革命性的影响。在努力提高电化学系统的选择性和能量效率的过程中，长期以来一直寻求在操作条件下直接研究电极反应的技术，以快速诊断极限过程。该项目将推进原位表征方法，以高分辨率描绘膜内化学成分和膜催化剂成分的分布。该项目的成果将有助于设计用于电化学系统的下一代膜。该项目还将吸引各个层次的学生参与研究，并将研究与指导、教育和外展相结合。该项目将加强针对初中和高中女性和代表性不足的少数民族学生的机构外展活动。研究人员将通过在母女计划（TTU和Lubbock美国大学妇女协会）和居里俱乐部（U Utah）中增加同伴指导部分来丰富他们的计划，旨在提高STEM学生的保留率。通过运用他们的专业科学经验，这些pi正在帮助鼓励挽留STEM学生，并影响他们所在地区服务不足的群体。在双极膜的研究中，离子耗竭、水积累和水分裂现象将在施加电压和跨膜pH梯度下进行研究，这对催化反应优化具有实际意义。基于可自旋铸造离子交换聚合物和氘同位素标记的移动离子，将构建一个膜系统，用于中子反射测量，以实现接近1 nm的空间分辨率，以描绘分离阴离子和阳离子交换相的界面。结果将为进一步发展质量传递和动力学模型提供基准，指导提高设备能量转换效率的策略。在另一个涉及生物催化膜应用的项目中，利用氮酶还原N2的多催化级联将通过使用氧化还原聚合物进行组装，从而促进电子转移和“布线”。电极组内的酶。基于悬垂的吩那嗪基团，对膜组成的原位空间测绘将指导修饰，以实现在单独的无酶电极盖层中对氮酶和O2清除的电子传递中介的双重作用。封盖层将减轻氮酶对O2的敏感性，并支持构建能够在空气中运行的常温N2到NH3转化平台的重要目标。所有中子反射测量都将与美国国家标准与技术研究院（NIST）中子研究中心合作进行。该奖项反映了美国国家科学基金会的法定使命，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。

Electrochemical systems, such as fuel cells and electrolyzers, have a central role in the development of electric vehicles and systems for renewable energy conversion, and recent revolutionary impact on specialty chemical synthesis. In striving to improve the selectivity and energy efficiency of electrochemical systems, techniques to directly study the reactions at electrodes under operating conditions have long been sought for the rapid diagnosis of the limiting processes. This project will advance in-situ characterization methods that profile the distribution of chemical components within membranes and membrane-catalyst components at high resolution. The project outcomes will aid the design of next-generation membranes for electrochemical systems. The project will also engage students across all levels in research and integrate research with mentoring, education and outreach. The project will strengthen institutional outreach activities targeting female and underrepresented minority students in middle schools and high schools. The investigators will enrich their programs with the addition of peer-mentoring components to the Mother-Daughter program (TTU and Lubbock American Association of University Women) and the Curie Club (U Utah) that aim to increase retention of students in STEM. By applying their professional scientific experiences, the PIs are helping to encourage retention of STEM students and impact underserved groups in their regions.In the study of bipolar membranes, the phenomena of ion-depletion, water accumulation, and water-splitting will be investigated under the applied voltages and transmembrane pH gradients that are of practical interest for catalytic reaction optimization. A membrane system, based on spin-castable ion-exchange polymers and deuterium isotope labeled mobile ions, will be constructed for neutron reflectometry measurements to enable attainment of spatial resolution approaching 1 nm in profiling the interface separating anion- and cation-exchange phases. Results will provide benchmarks for furthering the mass transport and kinetic models that guide strategies for improving device energy conversion efficiency. In another project example involving biocatalytic membrane applications, a multi-catalytic cascade utilizing nitrogenase enzymes for N2 reduction will be assembled through the use of redox polymers that facilitate electron transfer and ?wiring? of enzymes within the electrode assembly. In-situ spatial mapping of membrane composition will guide modifications, based on pendant phenathiazine moieties, for the dual role of electron transport mediation to nitrogenase and O2 scavenging in a separate, enzyme-free electrode capping layer. The capping layer will mitigate nitrogenase sensitivity toward O2 and support efforts toward the important goal of constructing ambient temperature N2 to NH3 conversion platforms capable of operation in air. All neutron reflectometry measurements will be conducted in collaboration with the National Institute of Standards and Technology (NIST) Center for Neutron Research.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.