Activity Trends and Mechanisms in Peroxymonosulfate‐Assisted Catalytic Production of Singlet Oxygen over Atomic Metal‐N‐C Catalysts

Abstract We synthesized a series of carbon‐supported atomic metal‐N‐C catalysts (M‐SACs: M=Mn, Fe, Co, Ni, Cu) with similar structural and physicochemical properties to uncover their catalytic activity trends and mechanisms. The peroxymonosulfate (PMS) catalytic activity trends are Fe‐SAC>Co‐SAC>Mn‐SAC>Ni‐SAC>Cu‐SAC, and Fe‐SAC displays the best single‐site kinetic value (1.65×10 5 min −1 mol −1 ) compared to the other metal‐N‐C species. First‐principles calculations indicate that the most reasonable reaction pathway for 1 O 2 production is PMS→OH*→O*→ 1 O 2 ; M‐SACs that exhibit moderate and near‐average Gibbs free energies in each reaction step have a better catalytic activity, which is the key for the outstanding performance of Fe‐SACs. This study gives the atomic‐scale understanding of fundamental catalytic trends and mechanisms of PMS‐assisted reactive oxygen species production via M‐SACs, thus providing guidance for developing M‐SACs for catalytic organic pollutant degradation.