Simultaneously Engineering the Coordination Environment and Pore Architecture of Metal–Organic Framework‐Derived Single‐Atomic Iron Catalysts for Ultraefficient Oxygen Reduction
Feng Liu, Lei Shi, Shaofeng Song, Kai Ge, Xiaopeng Zhang, Yingchun Guo, Dong Liu
Abstract
Abstract Designing highly efficient and durable electrocatalysts that accelerate sluggish oxygen reduction reaction kinetics for fuel cells and metal–air batteries are highly desirable but challenging. Herein, a facile yet robust strategy is reported to rationally design single iron active centers synergized with local S atoms in metal–organic frameworks derived from hierarchically porous carbon nanorods (Fe/N,S‐HC). The cooperative trithiocyanuric acid‐based coating not only introduces S atoms that regulate the coordination environment of the active centers, but also facilitates the formation of a hierarchically porous structure. Benefiting from electronic modulation and architectural functionality, Fe/N,S‐HC catalyst shows markedly enhanced ORR performance with a half‐wave potential ( E 1/2 ) of 0.912 V and satisfactory long‐term durability in alkaline medium, outperforming those of commercial Pt/C. Impressively, Fe/N,S‐HC‐based Zn–air battery also presents outstanding battery performance and long‐term stability. Both electrochemical experimental and density functional theoretical (DFT) calculated results suggest that the FeN 4 sites tailored with local S atoms are favorable for the adsorption/desorption of oxygen intermediate, resulting in lower activation energy barrier and ultraefficient oxygen reduction catalytic activity. This work provides an atomic‐level combined with porous morphological‐level insights into oxygen reduction catalytic property, promoting rational design and development of novel highly efficient single‐atom catalysts for the renewable energy applications.