Indirect electrosynthesis of ammonia from nitrogen and water by a magnesium chloride cycle at atmospheric pressure

Hu, Yang; Chen, George Z.; Zhuang, Lin; Wang, Zhiyong; Jin, Xianbo

Abstract

Artificial N2 fixation is one of the most important industrial processes for human beings. However, the current Haber-Bosch process based on fossil fuel suffers from unsustainability and a low N2 to NH3 conversion. Here, we report a magnesium chloride cycle for the synthesis of NH3 from N2 and H2O at atmospheric pressure. In this cycle, N2 reacts with Mg to form Mg3N2. Mg and Cl2 are produced by the electrolysis of molten MgCl2. NH4Cl is used to hydrogenolyze Mg3N2 to produce NH3, with anhydrous MgCl2 being regenerated. The cycle is closed via the reverse Deacon reaction to convert Cl2 to HCl, which is captured as NH4Cl with the recyclable NH3. This indirect electrosynthesis produces NH3 at an industry-acceptable rate with zero CO2 emission, a coulombic efficiency >92%, and an energy consumption of ?14.1 kWh/kg-NH3.

Citation

Hu, Y., Chen, G. Z., Zhuang, L., Wang, Z., & Jin, X. (2021). Indirect electrosynthesis of ammonia from nitrogen and water by a magnesium chloride cycle at atmospheric pressure. Cell Reports Physical Science, 2(5), Article 100425. https://doi.org/10.1016/j.xcrp.2021.100425

• Journal Article Type: Article
• Acceptance Date: Apr 14, 2021
• Online Publication Date: May 4, 2021
• Publication Date: May 19, 2021
• Deposit Date: May 6, 2021
• Publicly Available Date: May 6, 2021
• Journal: Cell Reports Physical Science
• Print ISSN: 2666-3864
• Electronic ISSN: 2666-3864
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 2
• Issue: 5
• Article Number: 100425
• DOI: https://doi.org/10.1016/j.xcrp.2021.100425
• Public URL: https://nottingham-repository.worktribe.com/output/5511782
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S2666386421001193?via%3Dihub