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开发中发挥着核心作用，最近对特种化学合成产生了革命性的影响。为了提高电化学系统的选择性和能量效率，长期以来一直在寻求直接研究操作条件下电极处的反应的技术，以快速诊断限制过程。该项目将推进原位表征方法，以高分辨率描绘膜内化学组分和膜催化剂组分的分布。该项目的成果将有助于电化学系统的下一代膜的设计。该项目还将使各级学生参与研究，并将研究与指导，教育和推广相结合。该项目将加强针对初中和高中女生和代表性不足的少数民族学生的机构外联活动。调查人员将丰富他们的计划，在母女计划（TTU和拉伯克美国大学妇女协会）和居里俱乐部（U犹他州）中增加同伴指导成分，旨在提高STEM学生的保留率。通过运用他们的专业科学经验，PI们正在帮助鼓励STEM学生的保留，并影响所在地区的弱势群体。在双极膜的研究中，将研究在施加电压和跨膜pH梯度下的离子耗尽，水积累和水裂解现象，这些现象对催化反应优化具有实际意义。将构建一个基于可旋转浇铸的离子交换聚合物和氘同位素标记的移动的离子的膜系统，用于中子反射测量，以在分析阴离子和阳离子分离界面时实现接近1纳米的空间分辨率交换相。研究结果将为进一步的质量传输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，利用固氮酶进行N2还原的多催化级联将通过使用氧化还原聚合物组装，促进电子转移和？接线？在电极组件内的酶。膜组合物的原位空间映射将指导修改，基于悬垂吩噻嗪部分，用于在单独的无酶电极帽层中对固氮酶和O2清除的电子传递介导的双重作用。覆盖层将减轻固氮酶对O2的敏感性，并支持努力实现构建能够在空气中操作的环境温度N2至NH3转化平台的重要目标。所有的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。

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.