Recent advances in metal single−atom catalysts for ammonia electrosynthesis

Abstract

Electrochemical ammonia synthesis is a promising alternative to the Haber−Bosch process, offering significant potential for sustainable agricultural production and the development of portable carbon-free energy carriers. The development of electrocatalytic systems mainly is currently dependent on the exploration of contributing electrocatalysts with high activity, selectivity, and stability. Metal single-atom catalysts have become a new attractive frontier for ammonia electrosynthesis owing to their maximized atom utilization, unsaturated atom coordination, and tunable electronic structure. In this study, we focus on different metal sites inside the single-atom catalysts and summarize recent advances in metal single-atom catalysts for ammonia electrosynthesis. First, the properties of nitrogenous raw small molecules (including N2, NO, NO2−, and NO3−) are summarized. In addition, the metal single-atom catalysts for different catalytic systems are reviewed, with a particular focus on the special and common grounds of metal atom sites. Finally, the perspectives and challenges of metal single-atom materials for ammonia electrosynthesis are comprehensively discussed, aspiring to provide insight into the development of electrochemical ammonia electrosynthesis.