Plasma‐Electrocatalysis Cascade Synthesis of Deuterated Ammonia

Deuterated ammonia (ND 3 ) exhibits growing market demand in the fields of chemical analysis, pharmaceutical industry and semiconductor manufacturing. Currently, industrial production of ND 3 relies on harsh conditions and complex processes, leading to high production cost and security risk. Herein, we propose a sustainable relay strategy to produce ND 3 by using air and deuterium oxide (D 2 O) as raw materials, including plasma‐driven air‐to‐NO x conversion and electrocatalytic NO x – ‐to‐ND 3 conversion. The insufficient supply of reactive deuterium (*D) leads to sluggish kinetics of electrocatalytic deuterium reaction. The well‐designed F modified cobalt (F–Co) catalyst exhibits a remarkable yield of 0.75 mmol h −1 cm −2 and a Faradaic efficiency of 80.43% for ND 3 at 200 mA cm −2 . The combined results of characterizations reveal that fluorine (F) atom can boost D 2 O dissociation and suppress competing deuterium evolution reaction, thereby providing abundant *D for deuteration reaction. Notably, a pilot‐scale demonstration system, consisting of non‐thermal plasma, flow electrolyzer, air stripping and ammonia absorber, is constructed to produce practicable ND 3 solution (2.8 wt%) with ∼21.45 mmol h −1 ND 3 production capability by using air and D 2 O as sources.