Plasma-enabled urea roadmap

Abstract

Conventional Haber–Bosch/Bosch–Meiser routes link global urea production to fossil fuel-based ammonia, accounting for ≈2% of the world’s energy use and ≈1.5% of CO₂ emissions. A modular, fully electrified alternative is charted that cleaves the problem at its natural fault line: a non-thermal plasma first upgrades air to nitrate, then a CO₂/NO₃⁻ co-electrolyzer stitches the two C─N bonds of urea at ambient conditions. The lens is deliberately cross-disciplinary: every bottleneck is probed with the question, “Has a cognate field already cracked this?” If so, how can the solution be mirrored here? Plasma physics contributes to vibrational pumping, power modulated reactors, and in water quenching; CO₂ and nitrate electro-reduction supply relay-site catalyst design, vacancy tuning, and pulsed-bias choreography; flow-battery engineering guides carbonate-resilient gas-diffusion electrodes (GDEs) and zero-gap membrane-electrode assemblies (MEAs); and analytical chemistry adds two-probe assays that unmask false-positive amine/amide signals. Stitching these advances together, techno-economic modeling shows that sub-megajoule plasmas, ≥70% urea-selective in the electrolyzer, and renewable electricity (RE) at ≤3.5¢ kWh⁻¹ can push green urea below the fossil-based benchmark.