Catalyst-ionomer interactions in electrochemical systems

包括聚合物电解质膜(PEM)燃料电池和水电解槽在内的电化学能量转换系统是通过广泛应用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数量方面取得了很大的改进。然而，通过优化催化剂和离子传导介质(称为离聚体)之间的界面，存在着进一步提高燃料电池/电解槽性能的重大机会。这项研究利用最先进的仪器，结合一套电化学表征方法，对催化层和离聚体之间的界面相互作用获得了前所未有的深入了解。由此产生的关于一系列催化系统中催化剂-离聚体相互作用的基本见解-在模拟设备操作的条件下-将直接转化为耐用、低成本的PEM燃料电池和其他水电解器系统的改进设计。这项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，确保未来训练有素的劳动力，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-离聚体界面和相互作用的基本了解，确定催化剂和载体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催化层表面研究的最佳实践和协议。各种原位条件下的X射线光电子能谱实验，结合互补表征，将研究催化剂-离聚体相互作用和界面在相关条件下的演变，这些材料包括三组日益复杂的材料：1)离聚体薄膜，2)催化剂-离聚体复合材料，3)集成电极。由此得出的见解将指导未来在设计新型催化剂系统和电极方面的工作，这些系统和电极具有优化的表面和界面，以及更好的性能和耐用性。从该项目中获得的知识将通过出版出版物、参加研讨会和会议以及与学术界、国家实验室和工业界的科学家密切互动等方式向广大受众传播。调查员将通过AVS科学教育者讲习班(SEW)和调查员所在机构的教师能源教育暑期讲习班(SMET)计划，为STEM教师的教育做出贡献。该项目还侧重于增加代表不足的少数群体的参与，并培训未来的领导人，能够通过可再生资源改变与清洁能源和气候影响有关的科学理解。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。

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.