Preparation of Fe, Co, Ni-based single atom catalysts and the progress of their application in electrocatalysis

Single-atom catalysts (SACs) have garnered considerable attention owing to their profound potential in promoting the efficient utilization of metal resources and attaining atomic-level economy. Fe, Co, Ni SACs have demonstrated broad application prospects in electrocatalysis due to their tunable composition and structure, as well as their unique electronic properties. Firstly, the various preparation methods for Fe, Co, Ni SACs are outlined in this review, including high-temperature pyrolysis, impregnation, chemical vapor deposition, and atomic layer deposition. These methods not only enhance the utilization efficiency of metal atoms but also ensure the stability of the catalysts. Subsequently, this review summarizes the recent progress in the applications of Fe, Co, Ni SACs for electrocatalysis, with a particular focus on their efficacy in hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, and nitrogen reduction reaction. Despite remarkable advancements, Fe, Co, Ni SACs still face challenges related to large-scale production, stability enhancement, comprehensive characterization, and mechanistic exploration. Finally, this review discusses these challenges and proposes strategies to address them in order to fully realize the potential of Fe, Co, Ni SACs as high-performance catalysts.