Single-Atom Catalysts: Synthetic Strategies and Electrochemical Applications

The performance and the cost of electrocatalysts play the two most vital roles in the development and application of energy conversion technologies. Single-atom catalysts (SACs) are recently emerging as a new frontier in catalysis science. With maximum atom-utilization efficiency and unique properties, SACs exhibit great potential for enabling reasonable use of metal resources and achieving atomic economy. However, fabricating SACs and maintaining the metal centers as atomically dispersed sites under synthesis and catalysis conditions are challenging. Here, we highlight and summarize recent advances in wet-chemistry synthetic methods for SACs with special emphasis on how to achieve the stabilization of single metal atoms against migration and agglomeration. Moreover, we summarize and discuss the electrochemical applications of SACs with a focus on the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and CO₂ reduction reaction (CO₂RR). At last, the current issues and the prospects for the development of this field are discussed.