Reactant-Induced Dynamic Catalysis in Co Single Atom Catalyst for Efficient Water Remediation

Elucidating the dynamic evolution of single-atom catalytic sites remains a fundamental challenge in advancing single-atom catalysis. While current studies primarily focus on stimulus-responsive structural transformations induced by external perturbations (e.g., electrochemical potential variations), the intrinsic self-adaptive mechanisms of active sites under ambient reaction conditions remain largely unexplored. Here, we report a reactant-induced dynamic coordination evolution in a nitrogen/oxygen dual-coordinated cobalt single-atom catalyst (Co–N 3 O 1 ) during peroxymonosulfate-based advanced oxidation processes (PMS-AOPs). Through operando X-ray absorption spectroscopy (XAS) combined with density functional theory (DFT) calculations, we identify a two-step reversible structural transition from the initial Co–N 3 O cat configuration to an O PMS ═Co–N 3 intermediate upon PMS activation, which subsequently reverts to the original Co–N 3 O cat state during phenol oxidation. This dynamic restructuring arises from a spontaneous d – p orbital rearrangement between Co 3 d orbitals and O 2 p orbitals of coordinating oxygen species, which selectively stabilize high-valent Co(IV)═O species. The optimized catalyst exhibits a 4-fold increase in activity compared to conventional Co–N 4 SACs, along with stable operation exceeding 120 h and effective treatment of real industrial coal chemical wastewater. This work provides atomically resolved evidence of stimulus-free, reactant-induced active-site dynamics and establishes a paradigm for designing adaptive single-atom catalysts with broad applicability in environmental and energy-related applications.