Dynamic Coordinated Geminal-atom Catalyst for Highly Efficient Photo-Fenton Reactions

Abstract Understanding and leveraging non-reactive species in natural environments to modulate the active centers of geminal-atom catalysts (GACs) is crucial for enhancing their catalytic performance. In this study, we present a two-coordinated geminal Cu atomic catalyst and, for the first time, uncover the mechanism by which dynamic metal second coordination shell and non-reactive species boost its photo-Fenton activity. This breakthrough enables the efficient removal of pollutants such as marine microorganisms, oils, and microplastics. Through experimental studies, operando X-ray absorption spectroscopy, and theoretical analyses, we demonstrate that the dynamic coordination environment promotes synergistic dual-atom interactions, and the second coordination shell influences the significant orbital overlap between the central metal and the delocalized ligand orbitals, enabling direct electron transfer. Additionally, the dynamic coordination of GACs induces a local spin transition, which lowers the reaction barrier through spin-crossover at the active site. This, in turn, reduces the spin-flip barrier for forming the singlet-state *OOH and OH-, thereby accelerating spin non-conservation reactions. The interactions between CO32- ions and adjacent Cu sites significantly alter the electronic structure of the catalytic centers. These modifications enhance charge transfer kinetics, leading to a remarkable 17-fold increase in hydroxyl radical production. This innovative approach—utilizing non-reactive species to amplify the photo-Fenton activity of Cu GACs—offers a constructive solution for environmental remediation in complex matrices and provides valuable guidance for designing high-performance catalysts tailored to challenging environmental conditions.