The use of dispersive single-atom metals anchored on functionalized carbon nanomaterials as electrocatalysts for electrochemical energy conversion reactions represents a burgeoning area of research, due to their unique characteristics of low coordination number, uniform coordination environment, and maximum atomic utilization. Here we highlight the advanced synthetic methods, characterization techniques, and electrochemical applications for carbon-based single-atom metal catalysts, and provide illustrative correlations between molecular/electronic structures and specific catalytic activity for O2 reduction, water splitting, and other emerging reactions including CO2 reduction, H2O2 production, and N2 reduction. We also discuss fundamental principles for the future design of carbon-based single-atom metal catalysts for specific electrochemical reactions. In addition, we explore the challenges and opportunities that lie ahead in further work with carbon-based single-atom metal electrocatalysts.
Keywords: Carbon dioxide reduction; Nitrogen reduction; Oxygen reduction; Single-atom metal catalysts; Water splitting.