Recent advances in carbon-supported non-precious metal single-atom catalysts for energy conversion electrocatalysis

Non-precious metal single-atom catalysts (NPM-SACs) with unique electronic structures and coordination environments have gained much attention in electrocatalysis owing to their low cost, high atomic utilization, and high performance. NPM-SACs on carbon support (NPM-SACs/CS) are promising because of the carbon substrate with a large surface area, excellent electrical conductivity, and high chemical stability. This review provides an overview of recent developments in NPM-SACs/CS for the electrocatalytic field. First, the state-of-the-art synthesis methods and advanced characterization techniques of NPM-SACs/CS are discussed in detail. Then, the structural adjustment strategy of NPM-SACs/CS for optimizing electrocatalytic performance is introduced concisely. Furthermore, we provide a comprehensive summary of recent advances in developing NPM-SACs/CS for important electrochemical reactions, including carbon dioxide reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and nitrogen reduction reaction. In the end, the existing challenges and future opportunities of NPM-SACs/CS in the electrocatalytic field are highlighted.