Designing Reactive Bridging O(2–) at the Atomic Cu–O–Fe Site for Selective NH(3) Oxidation

[Image: see text] Surface oxidation chemistry involves the formation and breaking of metal–oxygen (M–O) bonds. Ideally, the M–O bonding strength determines the rate of oxygen absorption and dissociation. Here, we design reactive bridging O(2–) species within the atomic Cu–O–Fe site to accelerate such oxidation chemistry. Using in situ X-ray absorption spectroscopy at the O K-edge and density functional theory calculations, it is found that such bridging O(2–) has a lower antibonding orbital energy and thus weaker Cu–O/Fe–O strength. In selective NH(3) oxidation, the weak Cu–O/Fe–O bond enables fast Cu redox for NH(3) conversion and direct NO adsorption via Cu–O–NO to promote N–N coupling toward N(2). As a result, 99% N(2) selectivity at 100% conversion is achieved at 573 K, exceeding most of the reported results. This result suggests the importance to design, determine, and utilize the unique features of bridging O(2–) in catalysis.