Investigation of Anodic Reaction of Electrolytic Ammonia Synthesis in Molten Salts Under Atmospheric Pressure

Abstract

The kinetics of a novel ammonia synthesis reaction (N3- + 3/2H2 → NH3 + 3e-) in molten salts were investigated. To evaluate current efficiencies and ammonia synthesis rates, potentiostatic electrolyses were conducted under various electrolysis conditions in molten LiCl-KCl-CsCl containing 0.5 mol % Li3N. The ammonia synthesis rate depended on the hydrogen partial pressure of the feed gas, not on the electrolysis potential. The relationship between ammonia synthesis rate and temperature was described by the Arrhenius equation, and the activation energy of the ammonia synthesis reaction was 69 kj mol-1. From the obtained results, the mechanism of the ammonia synthesis reaction was discussed. © 2005 The Electrochemical Society. All rights reserved.