Dataset of "Effects of Loading and Nafion Content on the Activity and Stability of Iridium Oxygen Evolution Reaction Catalysts"

Proton-exchange-membrane water electrolysis (PEMWE) is a leading technology for scalable, carbon-free hydrogen production, but its widespread adoption is limited by the cost and scarcity of iridium (Ir) oxygen-evolution catalysts. To develop stable, low-loading anodes, standardized testing procedures must be established based on a clear understanding of how each catalyst-layer component, including the catalyst loading and ionomer binder, affects performance and degradation. Here, we systematically investigate how catalyst loading and Nafion ionomer content affect the activity–stability tradeoff in metallic Ir and thermally prepared IrOx. Real-time Ir dissolution is tracked using scanning flow cell coupled with inductively coupled plasma mass spectrometry (SFC-ICP-MS) and benchmarked with rotating-disk electrode (RDE) measurements, while morphology and interfacial properties are analyzed by SEM-EDX, X-ray photoelectron spectroscopy, and contact-angle goniometry. Varying Ir loading has minimal effect on the activity or dissolution of metallic Ir. By contrast, Nafion–catalyst interactions strongly influence both utilization and degradation: weak binding on metallic Ir leads to poor dispersion, coffee-ring effects, and reduced electrochemically active surface area, while strong binding on IrOx improves dispersion and boosts activity at moderate loadings but increases dissolution, likely due to sulfonate interactions or reduced agglomerate size. Across both catalysts, 10 wt.% Nafion provides the best balance between performance and durability. These results demonstrate the critical role of interfacial chemistry in electrocatalyst design and offer practical guidance for developing low-loading, durable PEMWE anodes for renewable hydrogen production.质子交换膜水电解（Proton-exchange-membrane water electrolysis, PEMWE）是规模化无碳制氢的主流技术，但其大规模推广应用受限于铱（iridium, Ir）基析氧催化剂的成本高昂与资源稀缺。为开发稳定的低负载阳极，需在明确认识催化剂层各组分（包括催化剂负载量与离聚物粘合剂）对性能与降解的影响机制的基础上，建立标准化测试流程。本研究系统探究了催化剂负载量与Nafion离聚物含量对金属铱（metallic Ir）及热制备氧化铱（thermally prepared IrOx）的活性-稳定性权衡关系的影响。研究采用扫描流动池-电感耦合等离子体质谱（scanning flow cell coupled with inductively coupled plasma mass spectrometry, SFC-ICP-MS）实时追踪铱的溶出行为，并以旋转圆盘电极（rotating-disk electrode, RDE）测试作为性能基准；同时通过扫描电镜-能谱（SEM-EDX）、X射线光电子能谱（X-ray photoelectron spectroscopy, XPS）与接触角测角仪表征催化剂的形貌与界面性质。研究发现，调控铱负载量对金属铱的催化活性与溶出行为影响极小。与之相反，Nafion与催化剂的界面相互作用对催化剂利用率与降解过程均存在显著调控作用：金属铱表面的弱结合作用会导致催化剂分散性不佳、出现咖啡环效应，并降低电化学活性比表面积；而氧化铱表面的强结合作用可改善催化剂分散性，在中等负载量下提升催化活性，但会因磺酸根基团相互作用或团聚体尺寸减小而加剧铱的溶出。对于两种催化剂体系，10 wt.%的Nafion均可实现催化性能与耐久性的最优平衡。本研究结果证实了界面化学在电催化剂设计中的关键作用，可为开发用于可再生能源制氢的低负载、高耐久性PEMWE阳极提供切实可行的指导。