Electron beam-induced decomposition of nitrous oxide (N₂O) and the critical role of oxygen

In recent years, nitrous oxide (N₂O) has emerged as a critical target for mitigation owing to its exceptional stability and significant potential to cause global warming. Conventional abatement technologies, including thermal, catalytic, and plasma-based technologies, are currently limited by economic and scalability constraints, hindering their practical deployment. In this study, we developed an electron beam (EB) radiolysis approach to decompose N₂O under ambient conditions. Utilizing an absorbed dose of 50 kGy, we achieved over 90 % decomposition of the 100 ppm N₂O in both N₂ and Ar backgrounds. However, oxygen inhibits radiolytic N₂O decomposition by facilitating the reformation of N₂O through reactions involving N₂- and O₂-derived reactive species. While net N₂O formation was observed from N₂ and O₂ mixtures, the introduction of initial N₂O effectively suppressed this process, demonstrating a distinct kinetic advantage for N₂O decomposition. Therefore, net N₂O decomposition was achieved when N₂O and O₂ concentrations were equivalent. The inhibitory effect of oxygen diminished at higher absorbed doses, indicating that elevated irradiation energies favor direct electron impact decomposition of N₂O over indirect pathways mediated by reactive species. These findings establish EB radiolysis as an efficient and scalable strategy for N₂O conversion. Moreover, they provide a clear scientific basis for addressing the challenges posed by oxygen in practical applications.