Reduction of N₂ to Ammonia by Phosphate Molten Salt and Li Electrode: Proof of Concept Using Quantum Mechanics
Charles B. Musgrave III, Sergey Morozov, William L. Schinski, William A. Goddard III
Abstract
Electrochemical routes provide an attractive alternative to the Haber–Bosch process for cheaper and more efficient ammonia (NH₃) synthesis from N₂ while avoiding the onerous environmental impact of the Haber–Bosch process. We prototype a strategy based on a eutectic mixture of phosphate molten salt. Using quantum-mechanics (QM)-based reactive molecular dynamics, we demonstrate that lithium nitride (Li₃N) produced from the reduction of nitrogen gas (N₂) by a lithium electrode can react with the phosphate molten salt to form ammonia. We extract reaction kinetics of the various steps from QM to identify conditions with favorable reaction rates for N₂ reduction by a porous lithium electrode to form Li₃N followed by protonation from phosphate molten salt (Li₂HPO₄–LiH₂PO₄ mixture) to selectively form NH₃.
Group Members
III, C. B. M., Morozov, S., Schinski, W. L., & III, W. A. G. (2021). Reduction of N₂ to Ammonia by Phosphate Molten Salt and Li Electrode: Proof of Concept Using Quantum Mechanics. *J. Phys. Chem. Lett.*, *12*(6), 1696-1701. https://doi.org/10.1021/acs.jpclett.0c03467