Insight into Structural Evolution, Active Sites, and Stability of Heterogeneous Electrocatalysts

Studying structure-activity correlations of electrocatalysts is essential for improving the conversion of electrical to chemical energy. Recently, increasing evidence obtained by operando characterization techniques reveal that the structural evolution of catalysts caused by the interplay with electric fields, electrolytes and reactants/intermediates brings about the formation of real active sites. Hence, it is time to summarize structural evolution related research advances and envisage future developments. In this Minireview, we first introduce the fundamental concepts associated with structural evolution (e.g., catalysts, active sites/centers and stability/lifetime) and their relevance. Then, the multiple triggers of structural evolution and advanced operando characterizations are discussed. Significantly, a brief overview of structural evolution and its reversibility in heterogeneous electrocatalysis is provided, especially for the representative electrocatalytic oxygen evolution reaction (OER) and CO2 reduction reaction (CO2RR) processes. Lastly, key challenges and opportunities in this exciting field are highlighted.

Automated summary

Studying the structure-activity correlations of electrocatalysts is crucial for improving the conversion of electrical to chemical energy. Recent evidence obtained through operando characterization techniques shows that the structural evolution of catalysts, caused by their interaction with electric fields, electrolytes, and reactants/intermediates, leads to the formation of real active sites. It is therefore important to summarize the research advances in structural evolution and envision future developments. In this Minireview, the fundamental concepts associated with structural evolution, the triggers of this evolution, and advanced operando characterizations are discussed. The reversibility of structural evolution in heterogeneous electrocatalysis, with a focus on the oxygen evolution and CO2 reduction reactions, is also highlighted. Finally, the key challenges and opportunities in this exciting field are presented.