Oxygen Dissociation by Concerted Action of Di-Iron Centers in Metal

The high chemical reactivity of unsaturated metalsites is a key factor for the development of novel devices withapplications in sensor engineering and catalysis. It is also centralin the research for sustainable energy concepts, e.g., the efficientproduction and conversion of chemical fuels. Here, we study theprocess of oxygen dissociation by a surface-supported metal organic network that displays close structural and functionalanalogies with the cofactors of non-heme enzymes. We synthesizea two-dimensional array of chemically active di-iron sites ona Cu(001) surface wheremolecular oxygen readily dissociates atroom temperature. We provide an atomic-level structural and electronic characterization before and after reaction by combiningscanning tunneling microscopy, X-ray absorption spectroscopy, and density functional theory. The latter identifies a novelmechanism for O2 dissociation controlled by the cooperative catalytic action of two Fe2+ ions. The high structural flexibility of theorganic ligands, the mobility of the metal centers, and the hydrogen bonding formation are shown to be essential for the functionalityof these active centers allowing to mimick biologically relevant reactions in a confined environment