A Pre‐Coordinated Strategy Precisely Tailors the Coordination Structure of Single‐Atom Sites Toward Efficient Catalysis

Abstract Coordination structure engineering represents a promising approach for optimizing the catalytic properties of single‐atom catalysts (SACs). However, the precise tailoring of single‐atom sites remains challenging. Herein, a pre‐coordination strategy is proposed to design SACs with tunable local coordination environments on 2D honeycomb‐like carbon nanofoams. By pre‐coordinating the metal precursor with customized functional groups on a layered Mg(OH) ₂ template through strong d‐p orbital hybridization, SACs featuring Co─N ₄ (Co ₁ /NC), Co─C ₄ (Co ₁ /CC), and Co─C ₂ S ₂ (Co ₁ /CSC) configurations are fabricated. The lamellar honeycomb‐like architecture facilitates active site exposure, reactant enrichment, and mass transfer during the reaction process. Consequently, the Co ₁ /NC catalyst, despite its extremely low Co loading of 0.12 wt.%, demonstrates exceptional catalytic activity and stability for nitroaromatics reduction, achieving an impressive overall turnover frequency (TOF) of 73668 h ⁻¹ for the conversion of 4‐nitrophenol to 4‐nitroaniline, surpassing most reported catalysts. Theoretical calculations indicate the Co─N ₄ configuration possesses moderate Fermi electronic states compared to Co─C ₄ and Co─C ₂ S ₂ , significantly promoting the formation and utilization of reactive H ^* species and accelerating the reaction kinetics for aromatic nitroreduction. This work establishes a novel avenue for the meticulous manipulation of coordination structures in SACs, paving the way for the advancement of sophisticated catalytic materials for chemical transformations.