LAUSR

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.