Electronic Synergy in Anti-Sandwich Dual-Atom Catalysts on BC3 for Efficient Hydrogen Evolution.

The development of efficient electrocatalysts for hydrogen generation is crucial for advancing clean and renewable energy technologies, yet the cooperative behavior governing dual-atom catalytic sites remains poorly clarified. In this study, an anti-sandwich dual-atom architecture supported on a BC3 monolayer is examined through comprehensive first-principles modeling. By jointly assessing hydrogen adsorption thermodynamics, metal anchoring strength, and dynamic stability under elevated-temperature ab initio molecular dynamics conditions, two structurally resilient configurations with nearly ideal hydrogen binding characteristics are identified. Detailed orbital-resolved electronic analyses, incorporating projected electronic states, bonding population evaluation, and charge redistribution visualization, indicate that hydrogen adsorption and reaction activity are predominantly controlled by interatomic electronic coupling and orbital hybridization within the dual-atom centers. These insights reveal the electronic essence of dual-atom synergy and establish a transferable design principle for developing high-efficiency anti-sandwich catalysts for hydrogen evolution.