Dissolution Behavior of Ammonia Electrosynthesized in Molten LiCl–KCl–CsCl System

The dissolution behavior of ammonia (NH 3 ) in a molten LiCl-KCl-CsCl system was studied in order to determine the feasibility of low-energy NH 3 production via electrochemical synthesis in a high temperature molten salt system. In the presence of nitride ion (N 3− ), a portion of NH 3 chemically dissolved in the melt as imide (NH 2− ) and amide (NH 2 − ) anions formed by the reaction between N 3− and NH 3 . Although the dissolved NH 2 − anion thermally decomposed to form NH 3 and NH 2− anion, this phenomena may lower the yield of electrochemical NH 3 production. The dissolved NH 3 can be recovered by supplying hydrogen or water vapor to the melt. The anodic reaction between N 3− and H 2 to form NH 3 at a hydrogen gas-diffusion electrode was also examined and the NH 3 yield was estimated. Although the competing N 2 evolution reaction occurred at potentials more positive than 1.2 V vs. Li(I)/Li, the conversion of Li 3 N approached 70%, following the recovery processes.