Mechanocatalytic Room-Temperature Synthesis of Ammonia from Its Elements Down to Atmospheric Pressure

Angew Chem Int Ed Engl. 2021 Dec 6;60(50):26385-26389. doi: 10.1002/anie.202112095. Epub 2021 Nov 8.

Abstract

Ammonia synthesis via the high-temperature and high-pressure Haber-Bosch process is one of the most important chemical processes in the world. In spite of numerous attempts over the last 100 years, continuous Haber-Bosch type ammonia synthesis at room-temperature had not been possible, yet. We report the development of a mechanocatalytic system operating continuously at room-temperature and at pressures down to 1 bar. With optimized experimental conditions, a cesium-promoted iron catalyst was shown to produce ammonia at concentrations of more than 0.2 vol. % for over 50 hours.

Keywords: ammonia synthesis; catalysis; gas-phase reactions; mechanochemistry; room-temperature.