The Structural Regulation of Electrocatalyst Nanomaterials via Electrochemical Tuning

The global energy crisis has intensified the demand for advanced electrocatalysts to facilitate critical key reactions in emerging energy technologies, such as fuel cells, water electrolysis, and metal-air batteries. Emerging from foundational research in metal-ion batteries, the metal ion electrochemical tuning (MET) methodology demonstrates exceptional precision in regulating reversible intercalation/deintercalation processes, distinguishing itself from other electrocatalyst preparation techniques. This innovative approach overcomes the inherent limitations of conventional methodologies, which primarily implement static compositional modifications while lacking the capability for dynamic performance optimization. This review systematically investigates the mechanistic foundations of MET and categorizes the process into three distinct operational modes based on the interaction between metal ions and the host catalyst material: ion intercalation, deintercalation, and repetitive intercalation/deintercalation. Significantly, these three operational modes modulate the geometric configurations and electronic structure of active sites through controlled induction of phase transitions, lattice strain, coordination environment alterations, and grain boundary engineering. The review subsequently evaluates the recent applications of MET-engineered electrocatalysts in key energy conversion processes. Finally, the review concludes with a critical examination of current challenges and future research directions, highlighting the paradigm-shifting potential of MET in developing the next generation of electrocatalysts for sustainable energy systems.