• A comprehensive discussion of monitoring the structure evolutions of catalysts during ORR via multiple in-situ techniques to identify the active sites is presented.

• The extensive applications of in-situ techniques in elucidating the oxygen reduction reaction (ORR) mechanisms/pathways are reviewed.

• The challenges and recommendations of current in-situ techniques for monitoring the various dynamic evolutions in ORR are pointed out.

中文翻译：

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原位探测电催化氧还原反应活性位点和机理的技术综述

• 全面讨论了通过多种原位技术监测 ORR 过程中催化剂的结构演变以识别活性位点。

• 综述了原位技术在阐明氧还原反应（ORR）机制/途径中的广泛应用。

• 指出了当前监测 ORR 各种动态演化的原位技术面临的挑战和建议。