Recent Progress of Carbon-Supported Single-Atom Catalysts for Energy Conversion and Storage

Single-atom catalysts (SACs) have the advantages of both homogeneous and heterogeneous catalysts, which show promising application potentials in many renewable energy-conversion technologies and critical industrial processes. In particular, carbon-supported SACs (CS-SACs) are of great interest because of their maximal atom utilization (∼100%), unique physicochemical structure, and beneficial synergistic effects between active catalytic sites and carbon substrates. In this review, we offer a critical overview of the unique advantages of CS-SACs related to their material designs, catalytic activities, and potential application areas. The state-of-the-art design and synthesis of CS-SACs are described under the framework of bottom-up and top-down approaches. We also comprehensively summarize recent advances in developing CS-SACs for important electrochemical reactions, i.e., oxygen reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, CO2 reduction reaction, nitrogen reduction reaction, serving as bi-/multi-functional electrocatalysts, and usages in supercapacitors and batteries. Lastly, the critical challenges and future opportunities in this emerging field are highlighted.