Energy-Efficient, Sustainable Nitrogen Fixation in Water via In Situ Electrode-Activated Pulsed Plasma

Abstract

Sustainable nitrogen fixation is essential for advancing agriculture and chemical production. However, existing methods face trade-offs between energy intensity and efficiency. Low-activation-energy approaches fail to dissociate nitrogen effectively due to the strong N₂ bond, while energy-intensive methods face energy loss from product decomposition. Here, we present an in-water plasma-based nitrogen fixation system that integrates metal electrodes (W, Al, and Fe) to achieve in situ activation of pulsed discharging plasma. This design enables efficient nitrogen dissociation and selective product formation of soluble nitrogen species (nitrate, nitrite, and ammonia), while minimizing decomposition through optimized product diffusion. This system achieves an energy consumption of 1.14 MJ mol^–1 and a production rate of 12.9 mmol h^–1 cm^–2 for total soluble nitrogen species, surpassing other water-assisted methods and rivaling the Haber–Bosch process. Operating under ambient conditions, this electricity-driven, carbon-neutral approach offers a sustainable and efficient solution for decentralized application in agriculture and chemical production.