Atomic‐Scale Structural Engineering of Carbon‐Supported Asymmetric Active Sites: Synergistic Enhancement in Electrocatalysis

Abstract In conventional single‐atom catalysts (SACs), active centers with high symmetry (such as the typical M─N 4 configuration) generally exhibit uniform electron distribution. This leads to excessively strong or weak adsorption of key reaction intermediates at active sites, rendering it difficult to achieve optimal activation. As a result, the further enhancement of catalytic efficiency is severely constrained. To address this limitation, disrupting structural symmetry is anticipated to finely tune the electronic structure, thereby optimizing the adsorption of key intermediates, altering the reaction pathway to lower the energy barrier, and improving catalytic activity. Although current research on asymmetric active sites is thriving, most related investigations focus on a single dimension. This review systematically summarizes the research progress of asymmetric active site catalysts from three perspectives: rational design, precise preparation, and application with mechanisms. First, heteroatoms are introduced to break traditional symmetric configurations, thereby constructing single‐atom and dual‐atom asymmetric active sites. Second, strategies such as spatial confinement, atom trapping, and ion recognition for the precise preparation of asymmetric active site catalysts are reviewed. Lastly, their outstanding performance in electrocatalytic applications is analyzed. It shows that asymmetric active sites optimize the intermediate reaction pathway. They reduce the catalytic energy barrier via cascade, auxiliary, and co‐adsorption mechanisms.