Recent trends and prospects in electrochemical nitrate reduction to ammonia with an emphasis on cobalt catalysts

Ammonia is gaining recognition as a promising energy carrier due to its high energy density, ease of liquefaction, and existing robust production and distribution infrastructure, particularly within the agricultural sector. The electrochemical nitrate reduction reaction (NO 3 RR), conducted under ambient conditions, offers a sustainable alternative to the energy-intensive Haber–Bosch (H B) process, addressing both environmental and energy challenges. Recent advancements in understanding catalytic mechanisms, optimizing catalytic systems, and designing advanced catalysts have substantially enhanced the efficiency of nitrate-to-ammonia conversion. Among these, cobalt (Co)-based electrocatalysts have emerged as a cost-effective and efficient alternative to noble metals, owing to their earth abundance, low cost, and favorable catalytic properties. This review provides a comprehensive overview of recent progress in NO 3 RR, emphasizing Co-based electrocatalysts. It delves into NO 3 RR mechanism analysis, critical considerations for system optimization, and innovative Co-based catalyst design strategies. Additionally, we explore current challenges and propose future directions for improving Co-based electrocatalyst performance, aiming to advance the rational design of efficient catalysts for sustainable ammonia synthesis. • Advances in understanding nitrate reduction mechanisms are discussed. • Critical catalytic system parameters factors affecting ammonia production efficiency are analyzed. • Cobalt-based catalyst design strategies are comprehensively presented. • Challenges and prospects for advancing cobalt-based catalysts and nitrate reduction system are addressed.