• • The proposed selectivity descriptors ΔΔG and ΔU provide a quantitative benchmark: ΔΔG (ΔG_N2 − ΔG_H) identifies the potential range where N2 adsorption dominates over H adsorption, while ΔU (U_cross – U_eNRR) specifies the potential range to trigger direct eNRR, enabling rational catalyst design to overcome HER competition.
• • Confined dual-atom configurations with optimized interatomic distances achieve simultaneous overwhelming N2 adsorption and sufficient activation, enabling ammonia synthesis with industrially relevant production rates and current density even at elevated potentials, directly addressing the premature decay in NH3 yield observed across reported catalysts.
• • The study employs constant-potential and solvation models within DFT (e.g., RPBE functional, DFT-D3 dispersion correction, and implicit solvation) to accurately capture potential-dependent competition, providing mechanistic insights into the root causes of eNRR performance limitations.
• • The work establishes a rational design framework for high-performance catalysts across a broad range of electrochemical transformations, moving beyond trial-and-error approaches by linking electronic structure descriptors to macroscopic performance metrics.