Abstract Harnessing renewable electricity to transform abundant environmental resources into fertilizers is central to sustainable development. Electrochemical nitrate‐to‐ammonia conversion provides a promising route, yet its efficiency is constrained by the elusive surface hydrogenation dynamics governing multi‐step *NO x reduction. Here, a cooperative descriptor (Ψ) derived from large‐language‐models‐assisted mining and energetic analysis successfully identifies NiCu single‐atom alloys (SAAs) as optimal catalysts. Pulse electrodeposition delivers atomically dispersed alloys with tunable structures, achieving a maximum Faradaic efficiency (FE) of ∼95% and yield rate (YR) of ∼11.4 mg h −1 cm −2 . In situ surface‐interrogation scanning electrochemical microscopy (SI‐SECM) provides quantitative information on the time‐resolved surface‐active hydrogen (*H) generation‐consumption and *NO x hydrogenation rate constants (NiCu > CoCu ≫ MnCu ≈ FeCu > Cu), directly aligning surface kinetics with selectivity. Theoretical investigations further confirmed that Ni doping lowers the barriers for *H formation and *NO x hydrogenation. A plasma‐electrochemical‐CO 2 capture system demonstrated continuous “air‐to‐fertilizer” conversion with reduced energy consumption and potential net‐negative emissions. These results establish a transferable design rule that bridges theoretical descriptors with operando hydrogenation dynamics, providing a mechanistic foundation and practical pathway toward scalable, zero‐carbon fertilizer production.
Yi et al. (2026) studied this question.