Advances of atomically dispersed catalysts from single-atom to clusters in energy storage and conversion applications

Owing to the special structural characteristics and maximized efficiency, atomically dispersed catalysts (ADCs) with different atom sizes ranged from the single atom to clusters can bridge the gap between heterogeneous and homogeneous catalysis. Tremendous progress has been made in ADCs including developing advanced synthesis strategies, promoting electrochemical performance and unraveling the underlying fundamental mechanisms. Herein, the recent progress of ADCs ranged from single-atom to clusters has been systematically reviewed with emphasis on key issues of synthesis methods, stabilization strategies, performance evaluation, mechanistic understanding, integrated experimental and theoretical studies in typical applications of energy storage and conversion, including oxygen reduction reaction in fuel cell and metal-air battery, oxygen evolution and hydrogen evolution reactions in water splitting, hydrogen oxidation reactions, carbon dioxide reduction and nitrogen reduction reaction. Centering on the topics, the most up-to-date results are present, along with the perspectives and challenges for the future development of ADCs.