Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489, Berlin, Germany.
Institute of Physics, Humboldt University Berlin, Newton-Straße 15, 12489, Berlin, Germany.
Angew Chem Int Ed Engl. 2023 Jul 3;62(27):e202219188. doi: 10.1002/anie.202219188. Epub 2023 Apr 17.
Metal/nitrogen-doped carbons (M-N-C) are promising candidates as oxygen electrocatalysts due to their low cost, tunable catalytic activity and selectivity, and well-dispersed morphologies. To improve the electrocatalytic performance of such systems, it is critical to gain a detailed understanding of their structure and properties through advanced characterization. In situ X-ray absorption spectroscopy (XAS) serves as a powerful tool to probe both the active sites and structural evolution of catalytic materials under reaction conditions. In this review, we firstly provide an overview of the fundamental concepts of XAS and then comprehensively review the setup and application of in situ XAS, introducing electrochemical XAS cells, experimental methods, as well as primary functions on catalytic applications. The active sites and the structural evolution of M-N-C catalysts caused by the interplay with electric fields, electrolytes and reactants/intermediates during the oxygen evolution reaction and the oxygen reduction reaction are subsequently discussed in detail. Finally, major challenges and future opportunities in this exciting field are highlighted.
金属/氮掺杂碳（M-N-C）作为氧电催化剂具有成本低、催化活性和选择性可调以及形态分散等优点，是很有前途的候选材料。为了提高这类体系的电催化性能，通过先进的表征方法深入了解其结构和性能至关重要。原位 X 射线吸收光谱（XAS）是一种强大的工具，可在反应条件下探测催化材料的活性位点和结构演变。在本综述中，我们首先提供了 XAS 的基本概念概述，然后全面综述了原位 XAS 的设置和应用，介绍了电化学 XAS 电池、实验方法以及在催化应用中的主要功能。随后详细讨论了在析氧反应和氧还原反应过程中，M-N-C 催化剂与电场、电解质和反应物/中间物相互作用引起的活性位点和结构演变。最后，强调了该令人兴奋的领域中的主要挑战和未来机遇。
