Electrocatalysts with atomic-level site for nitrate reduction to ammonia

Ammonia (NH3) is an important raw material for modern agriculture and industry, being widely demanded to sustain the sustainable development of modern society. Currently, the industrial production methods of NH3, such as the traditional Haber-Bosch process, have drawbacks including high energy consumption and significant carbon dioxide emissions. In recent years, the electrocatalytic nitrate reduction reaction (NO3RR) powered by intermittent renewable energy sources has gradually become a multidisciplinary research hotspot, as it allows for the efficient synthesis of NH3 under mild conditions. In this review, we focus on the research of electrocatalysts with atomic-level site, which have attracted attention due to their extremely high atomic utilization efficiency and unique structural characteristics in the field of NO3RR. Firstly, we introduce the mechanism of nitrate reduction for ammonia synthesis and discuss the in-situ characterization techniques related to the mechanism study. Secondly, we review the progress of the electrocatalysts with atomic-level site for nitrate reduction and explore the structure-activity relationship to guide the rational design of efficient catalysts. Lastly, the conclusions of this review and the challenges and prospective of this promising field are presented.