关键词: 基于铁的电催化剂, 原位/操作分析, 墨斯鲍尔谱学, 氧还原反应, 结构-活性关系

Abstract: Exploring cost-effective and efficient catalysts for the oxygen reduction reaction (ORR) poses a significant challenge, especially in the pursuit of alternatives to precious metals like platinum. Significant advancements have driven electrochemists to develop efficient ORR catalysts using abundant materials, particularly iron (Fe)-based, known for their exceptional performance in the ORR. While the crucial function of Fe in boosting ORR catalytic activity is recognized, the connection between material attributes and catalytic performance remains enigmatic. Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts. Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of Fe species in catalysis, facilitating the identification of active sites and the clarification of catalytic mechanisms. By showcasing noteworthy case studies within this review, we demonstrate the application of in-situ/operando ⁵⁷Fe Mössbauer spectroscopy across diverse Fe-involved materials in ORR catalysis. This sheds light on various aspects of ORR catalysis, such as identifying active sites, assessing stability, and understanding the reaction mechanism. Our inquiry drives towards the opportunities and hurdles allied with Mössbauer spectroscopy, unveiling potential breakthroughs and avenues for enhancement within this pivotal research realm.

Key words: Iron-based electrocatalysts, In-situ/operando analysis, Mossbauer spectroscopy, Oxygen reduction reaction, Structure-activity relationships