Dual Activation of N₂ and CO₂ toward N-O Coupling by Single Copper Ions

Concurrent activation and conversion of N₂ and CO₂ are of significance yet face numerous obstacles due to the large dissociation energies of N≡N and C═O bonds. Utilizing a specifically developed reflectron time-of-flight mass spectrometer, we investigated the dual activation of N₂ and CO₂ mediated by copper and silver ions under ambient conditions. Isotope experiments identified that both N₂ and CO₂ can be effectively activated to generate a N-O coupling product (NO⁺), especially in the presence of copper ions, and the NO⁺ product attains the maximum intensity with an N₂/CO₂ ratio of 1:2, which validates a three-molecule reaction mechanism, namely, N₂ + 2CO₂ → 2NO + 2CO. Through detailed analyses of thermo-dynamics and reaction dynamics, we illustrate the Cu⁺-catalyzed three-molecule reaction mechanism for N-O coupling, validating the dual activation of N₂ and CO₂ simply by plasma-assisted single-ion catalysis.