Ammonia synthesis roadmap

Abstract

Electrifying ammonia production demands modular systems powered entirely by renewable energy, eliminating dependence on fossil-derived hydrogen. This perspective argues that coupling non-thermal plasma oxidation of air to nitric oxide (NO) with five-electron electrocatalytic NO-to-NH₃ reduction (NORR) is a promising, energy-efficient and cost-realistic pathway. Drawing on lessons from mature electrochemical platforms, we identify the key mechanistic challenges and system-level gaps and translate them into targeted engineering strategies bounded by explicit techno-economic constraints. Our density functional theory analysis reveals a hidden bottleneck in nitrate-based pathways: slow nitrite desorption in an eight-electron/nine-proton deoxygenation and hydrogenation cascade, which NORR circumvents. To achieve industrially relevant rates and selectivity, we quantify the engineered reaction microenvironment, clarify associative versus dissociative pathways, and emphasise the role of gas-fed membrane assemblies and flow-by gas-diffusion electrodes. We also address integration, durability, and electrolyser design compatible with scale-out plasma–electrolyser architectures and set performance targets linked to TRLs. Finally, integrated techno-economic modelling indicates that NORR can reach cost parity with Haber–Bosch supplied by electrolytic hydrogen by ∼2035, with the potential to capture ∼1–5% of the global ammonia market by 2050 via distributed, modular deployment.