Coupling of N₂ and O₂ in the Gas Phase to Synthesize Nitric Oxide at Room Temperature: A Zeldovich-Like Strategy

Dinitrogen (N₂) activation and its chemical transformations are some of the most challenging topics in chemistry. Herein, we report that heteronuclear metal anions AuNbBO^- can mediate the direct coupling of N₂ and O₂ to generate NO molecules. N₂ first forms the nondissociative adsorption product AuNbBON₂^- on AuNbBO^-. In the following reactions with two O₂ molecules, two NO molecules are gradually released, with the formation of AuNbBO₂N^- and AuNbBO₃^-. In the reaction with the first O₂, the generated nitrene radical (N^••-) originating from the dissociated N₂, induces the activation of O₂. Subsequently, the second O₂ is anchored and forms a superoxide radical (O₂^•-); this radical attacks the other N atom to form an N-O bond, releasing the second NO. The N^••- and O₂^•- radicals play key roles in the reactions. The mechanism adopted in this direct oxidation of N₂ by O₂ to NO can be labeled as a Zeldovich-like mechanism.