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

Abstract

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.