Recent Advances in Electrochemical Nitrogen Reduction Reaction to Ammonia from the Catalyst to the System

As energy-related issues increase significantly, interest in ammonia (NH3) and its potential as a new eco-friendly fuel is increasing substantially. Accordingly, many studies have been conducted on electrochemical nitrogen reduction reaction (ENRR), which can produce ammonia in an environmentally friendly manner using nitrogen molecule (N-2) and water (H2O) in mild conditions. However, research is still at a standstill, showing low performances in faradaic efficiency (FE) and NH3 production rate due to the competitive reaction and insufficient three-phase boundary (TPB) of N-2(g)-catalyst(s)-H2O(l). Therefore, this review comprehensively describes the main challenges related to the ENRR and examines the strategies of catalyst design and TPB engineering that affect performances. Finally, a direction to further develop ENRR through perspective is provided.