Surface self-reconstruction of catalysts in electrocatalytic oxygen evolution reaction

In the last few decades, great progress has been made in electrocatalysis and related potential sustainable energy technologies. Particularly, with recent developments of various in situ and operando techniques, it has been widely observed that most earth-abundant transition metal-based oxygen evolution reaction (OER) catalysts undergo a surface self-restructuring process as a result of electro-derived oxidation within a certain range of applied potentials, usually accompanied by the increase of electrocatalytic OER activity. Such surface self-reconstruction of OER catalysts has made it difficult to effectively recognize the true catalytic active sites, thus hindering the in-depth understanding of the true electrocatalytic mechanism. Consequently, a comprehensive understanding of the surface self-reconstruction process plays a critical role in establishing a clear structure-composition-performance interrelation to obtain high-efficiency OER catalysts. In this article, we summarize recent advances in surface self-reconstruction of transition metal-based OER catalysts, with the emphasis on fundamental knowledge, tracking of surface self-reconstruction, structure-performance relationships, and strategies for activating surface self-reconstruction.