The growing need to store increasing amounts of renewable energy has recently triggered substantial R&D efforts towards efficient and stable water electrolysis technologies. The oxygen evolution reaction (OER) occurring at the electrolyser anode is central to the development of a clean, reliable and emission-free hydrogen economy. The development of robust and highly active anode materials for OER is therefore a great challenge and has been the main focus of research. Among potential candidates, perovskites have emerged as promising OER electrocatalysts. In this study, by combining a scalable cutting-edge synthesis method with time-resolved X-ray absorption spectroscopy measurements, we were able to capture the dynamic local electronic and geometric structure during realistic operando conditions for highly active OER perovskite nanocatalysts. Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ as nano-powder displays unique features that allow a dynamic self-reconstruction of the material’s surface during OER, that is, the growth of a self-assembled metal oxy(hydroxide) active layer. Therefore, besides showing outstanding performance at both the laboratory and industrial scale, we provide a fundamental understanding of the operando OER mechanism for highly active perovskite catalysts. This understanding significantly differs from design principles based on ex situ characterization techniques.

中文翻译：

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动态表面自我重建是高活性钙钛矿纳米电催化剂用于水分解的关键

存储越来越多的可再生能源的需求不断增长，最近引发了对高效，稳定的水电解技术的大量研发工作。在电解阳极处发生的析氧反应（OER）对于开发清洁，可靠且无排放的氢经济至关重要。因此，开发用于OER的坚固，高活性阳极材料是一个巨大的挑战，并且一直是研究的主要重点。在潜在的候选物中，钙钛矿已经成为有前途的OER电催化剂。在这项研究中，通过将可扩展的尖端合成方法与时间分辨的X射线吸收光谱法测量相结合，我们能够捕获现实操作过程中的动态局部电子和几何结构活性OER钙钛矿纳米催化剂的制备条件。的Ba _0.5锶_0.5钴_0.8铁_0.2 ø _{3- δ}作为纳米粉末显示独特的功能，其允许材料的动态自重建' OER在S表面，即，自组装金属氧的生长（氢氧化物）活动层。因此，除了在实验室和工业规模上均表现出出色的性能外，我们还提供了对高活性钙钛矿催化剂的操作性OER机理的基本了解。这种理解与基于异地表征技术的设计原理有很大不同。