Electrochemical ammonia synthesis through N2 and H2O under ambient conditions: Theory, practices, and challenges for catalysts and electrolytes

Abstract Due to its high energy density, carbon-free character, and the convenience for storage and transportation, ammonia (NH3) is considered as an energy vector, capable of being used for energy storage and directly as a fuel. Increasing demands for ammonia have necessitated the development of alternative synthesis approaches as the backup technology to the energy-intensive Haber-Bosch process. Among others, the electrosynthesis of ammonia (ESA) technology offers a promising approach to produce NH3 via a cathodic nitrogen reduction reaction (NRR). However, current ESA technologies desperately suffer from insufficient production rates (