Symmetry breaking of single-atom catalysts in heterogeneous electrocatalysis: reactivity and configuration

. Our analysis reveals that such symmetry breaking redistributes electron density around the metal center, lifts orbital degeneracy, and optimizes the d-band center, leading to enhanced intermediate adsorption, accelerated reaction kinetics, and broken scaling relationships. Furthermore, these asymmetrically configured SACs exhibit improved stability through strengthened metal-support interactions. While significant progress has been made, we conclude that future efforts must address the challenges of atomic-level precision, stability under operation, and scalable synthesis to fully realize the potential of symmetry-broken SACs across various electrocatalytic applications, thereby establishing a new paradigm for the rational design of advanced electrocatalytic materials.