Electro-synthesis of ammonia from nitrogen at ambient temperature and pressure in ionic liquids

• Published in: Energy & environmental science Vol. 1; no. 12; pp. 2516 - 252
• Main Authors: Zhou, Fengling, Azofra, Luis Miguel, Ali, Muataz, Kar, Mega, Simonov, Alexandr N, McDonnell-Worth, Ciaran, Sun, Chenghua, Zhang, Xinyi, MacFarlane, Douglas R
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2017
• Subjects: Ambient temperature; Ammonia; Carbon dioxide; Carbon dioxide emissions; Chemical synthesis; Electrochemistry; Energy resources; Energy sources; Fertilizers; Fossil fuels; Haber Bosch process; High temperature; Hydrogen-based energy; Ionic liquids; Ions; Nitrogen; Pressure; Renewable energy; Temperature effects
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c7ee02716h

Ammonia as the source of most fertilizers has become one of the most important chemicals globally. It also is being increasingly considered as an easily transported carrier of hydrogen energy that can be generated from "stranded" renewable-energy resources. However, the traditional Haber-Bosch process for the production of ammonia from atmospheric nitrogen and fossil fuels is a high temperature and pressure process that is energy intensive, currently producing more than 1.6% of global CO 2 emissions. An ambient temperature, electrochemical synthesis of ammonia is an attractive alternative approach, but has, to date, not been achieved at high efficiency. We report in this work the use of ionic liquids that have high N 2 solubility as electrolytes to achieve high conversion efficiency of 60% for N 2 electro-reduction to ammonia on a nanostructured iron catalyst under ambient conditions. High faradaic efficiency reduction of N 2 to NH 3 is achieved in ionic liquid media under ambient conditions.