Single‐Atom Fe Catalysts for Fenton‐Like Reactions: Roles of Different N Species

Abstract Recognizing and controlling the structure–activity relationships of single‐atom catalysts (SACs) is vital for manipulating their catalytic properties for various practical applications. Herein, Fe SACs supported on nitrogen‐doped carbon (SA‐Fe/CN) are reported, which show high catalytic reactivity (97% degradation of bisphenol A in only 5 min), high stability (80% of reactivity maintained after five runs), and wide pH suitability (working pH range 3–11) toward Fenton‐like reactions. The roles of different N species in these reactions are further explored, both experimentally and theoretically. It is discovered that graphitic N is an adsorptive site for the target molecule, pyrrolic N coordinates with Fe(III) and plays a dominant role in the reaction, and pyridinic N, coordinated with Fe(II), is only a minor contributor to the reactivity of SA‐Fe/CN. Density functional theory (DFT) calculations reveal that a lower d‐band center location of pyrrolic‐type Fe sites leads to the easy generation of Fe‐oxo intermediates, and thus, excellent catalytic properties.