Catalyst-ionomer interactions in electrochemical systems

包括聚合物电解质膜（PEM）燃料电池和水电解器的电化学能量转换系统是通过广泛实施可再生氢来减少全球化石燃料依赖的核心。 在减少高性能所需的昂贵贵金属的量方面已经取得了很大的进步。 然而，通过优化催化剂和称为离聚物的离子传导介质之间的界面，存在进一步改善燃料电池/电解槽性能的显著机会。 该研究利用最先进的仪器，结合一套电化学表征方法，以获得前所未有的洞察力关于催化剂层和离聚物之间的界面相互作用。 由此产生的关于催化剂-离聚物相互作用在一系列催化系统中的基本见解-在模拟设备操作的条件下-将直接转化为耐用，低成本PEM燃料电池和其他水电解槽系统的改进设计。 该研究涉及一系列相互关联的研究和教育目标，旨在扩大电化学设备的知识，确保训练有素的未来劳动力，并强调可再生能源对更广泛公众的重要性。该项目将发展对催化剂-离聚物界面和相互作用的基本理解，确定催化剂和支持化学和形态对这些界面和相互作用的影响，并跟踪持续电化学反应下界面结构和组成的演变。该项目还将建立可应用于其他系统的PEM催化剂层表面研究的最佳实践和协议。在原位条件下的各种X射线光电子能谱实验，结合互补表征，将研究在暴露于三种日益复杂的材料组的相关条件期间催化剂-离聚物相互作用和界面的演变：1）离聚物薄膜，2）催化剂-离聚物复合材料，和3）集成电极。 由此产生的见解将指导未来设计具有优化表面和界面以及改进性能和耐用性的新型催化剂系统和电极的工作。将通过出版物、参加讲习班和会议以及与来自学术界、国家实验室和工业界的科学家密切互动，向广大受众传播从该项目获得的知识。调查员将通过AVS科学教育工作者研讨会（SEW）和调查机构的教师能源教育夏季研讨会（SWEET）计划为STEM教师的教育做出贡献。 该项目还侧重于增加代表性不足的少数群体的参与，并培养能够通过可再生资源转变与清洁能源和气候影响有关的科学认识的未来领导者。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 energy conversion systems including polymer electrolyte membrane (PEM) fuel cells and water electrolyzers are central to reducing global fossil fuel dependence through widespread implementation of renewable hydrogen. Great improvements have been made in reducing the amount of expensive noble metals needed for high-performance. Nevertheless, significant opportunity exists for further improving fuel cell/electrolyzer performance through optimization of the interface between the catalyst and the ion-conducting medium known as the ionomer. The study utilizes state-of-the-art instrumentation, combined with a suite of electrochemical characterization methods, to gain unprecedented insight regarding the interfacial interactions between the catalyst layers and the ionomer. The resulting fundamental insights regarding catalyst-ionomer interactions across a range of catalytic systems – under conditions emulating device operation – will translate directly to improved designs of durable, low-cost PEM fuel cells and other water electrolyzer systems. The study involves a set of interconnected research and educational goals, both aimed at expanding knowledge of electrochemical devices, ensuring a highly trained future workforce, and highlighting the importance of renewable energy to the broader public.The project will develop fundamental understanding of catalyst-ionomer interfaces and interactions, determine the effects of catalyst and support chemistry and morphology on these interfaces and interactions, and track evolution of interfacial structure and composition under sustained electrochemical reaction. The project will also establish best practices and protocols for PEM catalyst layer surface studies that can be applied to other systems. A variety of X-ray photoelectron spectroscopy experiments under in situ conditions, in conjunction with complementary characterization, will investigate the evolution of both catalyst-ionomer interactions and interfaces during exposure to relevant conditions for three material sets of increasing complexity: 1) ionomer thin films, 2) catalyst-ionomer composites, and 3) integrated electrodes. The resulting insights will guide future work in designing novel catalyst systems and electrodes with optimized surfaces and interfaces as well as improved performance and durability. Knowledge obtained from this project will be disseminated to a wide audience through publications, participation in workshops and conferences, and close interactions with scientists from academia, national labs, and industry. The investigator will contribute to the education of STEM teachers through the AVS Science Educators workshop (SEW) and through the Summer Workshop on Energy Education for Teachers (SWEET) program at the investigator’s institution. The project also focuses on increasing participation from underrepresented minority groups and training future leaders capable of transforming scientific understanding related to clean-energy and climate impact via renewable resources.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.