Mechanistic and selectivity challenges in Li-mediated electrochemical nitrogen reduction

Lithium-mediated electrochemical nitrogen reduction (Li-mediated e-NRR) presents a promising pathway for sustainable ammonia synthesis, offering a potential alternative to the energy-intensive Haber–Bosch process. Despite notable advances, several critical challenges remain in realizing its practical application. Chief among these is the sluggish kinetics of nitrogen activation and reduction, which are strongly influenced by catalyst design, electrolyte composition, interfacial dynamics, and competing side reactions, such as hydrogen evolution. Recent computational and experimental studies have highlighted the vital role of Li-based intermediates, particularly Li₃N and LiNH₂, as well as the importance of catalyst morphology, defect engineering, and heterostructure formation in promoting N₂ activation and improving selectivity. However, the complexity of reaction pathways and the difficulty in identifying transient intermediates hinder mechanistic understanding. Key challenges also include limited knowledge of the functional role of Li in the reaction cycle, the lack of robust operando analytical tools, and the need for predictive modeling under realistic reaction conditions. Furthermore, scaling up Li-mediated systems requires innovation in flow cell architecture, durable materials, and safer electrolyte strategies, alongside considerations of lithium availability and environmental impact. Ongoing collaboration across disciplines is crucial to overcome the mechanistic, technological, and sustainability hurdles, paving the way for the development of advanced electrochemical systems capable of producing ammonia efficiently and scalable basis.