Atomically Precise Coinage Metal Nanoclusters with Exposed Metal Sites: Unlocking Reactivity and Functionality

Abstract Atomically precise coinage metal nanoclusters (Au, Ag, Cu) with exposed metal sites have garnered significant interest due to their exceptional catalytic properties and tunable electronic structures. These nanoclusters (NCs) provide a unique platform for optimizing catalytic reactions, including CO ₂ reduction, hydrogenation, oxidation, and electrochemical water splitting. This review offers an overview of strategies to create and stabilize exposed metal sites in NCs, focusing on ligand engineering, heteroatom doping, and hybrid surface modifications. It is explored how atomic‐level precision enhances catalytic performance, particularly in electrocatalytic CO ₂ reduction, hydrogen evolution reaction (HER), and oxygen evolution reaction (OER). Additionally, the catalytic efficiency of these NCs is highlighted in selective reduction and oxidation reactions, such as hydrogenation and C─O bond formation. The review also discusses the effects of structural design, metal doping, and alloying on catalytic performance, along with the role of NC encapsulation in polyoxometalates (POMs) for improved stability and efficiency. Finally, challenges related to the stability of NCs under harsh conditions are addressed and provide insights into future research aimed at improving scalability, durability, and efficiency for sustainable energy conversion and green catalysis applications.