A Perspective on Cu-Based Electrocatalysts for Nitrate Reduction for Ammonia Synthesis

Compared to the Haber-Bosch (H-B) process for ammonia synthesis with massive emission of greenhouse CO2 and necessary harsh reaction conditions, the electrocatalytic NO3- reduction (NO3RR) for ammonia synthesis under ambient temperature and pressure driven by renewable electricity has attracted great attention. NO3RR is also a promising route to construct nitrogen cycles utilizing NOx produced from industrial and agricultural operations. Cu-based catalyst is one of the most promising platforms for this reaction. This perspective shows the latest understanding and research advances on the NO3RR by Cu-based electrocatalysts. Through a deep analysis on the rate-limiting step of NO3RR, the strategies of overcoming the deactivation and enhancing the performance of Cu-based catalysts are discussed. The great significance of synergistic NOx and H activation in promoting the key kinetic step of electrocatalytic NO3RR by single-atom, oxide, bimetallic of Cu on the catalytic reaction site construction with tunable adsorption of N-containing intermediate and active H is stressed. Also, future challenges and perspectives toward coupling reaction of nitrate reduction catalyzed by Cu-based catalysts are proposed. This perspective can move forward the future research on electrocatalytic NO3RR to ammonia synthesis over advanced Cu-based electrocatalysts.