In situ NMR-guided design of alkaline electrochemical ammonia synthesis.

Abstract

As a low-carbon and decentralized ammonia synthetic method, lithium-mediated electrochemical synthesis has shown promising Faradaic efficiencies and reaction rates. Nevertheless, challenges including low energy efficiency and long-term stability need to be addressed. Here, we develop and apply in situ NMR methodology to reveal a range of reaction mechanisms, including plating of metallic lithium and the concurrent corrosion, nitrogen splitting on lithium metal, protonolysis of lithium nitride, and the formation of lithium ethoxide. Guided by the NMR insights, we demonstrate a biphasic alkaline-organic lithium-mediated electrochemical ammonia synthesis coupled with value-added organic conversion via alcohol and furfural oxidation. This approach provides a strategy to increase the anodic charge utilization and improve the overall energy efficiency of lithium-mediated ammonia synthesis.