Fully Exposed Cluster Catalyst (FECC): Toward Rich Surface Sites and Full Atom Utilization Efficiency

Increasing attention has been paid to single-atom catalysts (SACs) in heterogeneous catalysis because of their unique electronic properties, maximized atomic utilization efficiency, and potential to serve as a bridge between the heterogeneous and homogeneous catalysis. However, SACs can have limited advantages or even constrained applications for the reactions that require designated metallic states with multiple atoms or surface sites with metal-metal bonds. As a cross-dimensional extension to the concept of SACs, fully exposed cluster catalysts (FECCs) offer diverse surface sites formed by an ensemble of metal atoms, for the adsorption and transformation of reactants/intermediates. More importantly, FECCs have the advantage of maximized atom utilization efficiency. Thus, FECCs provide a novel platform to design effective and efficient catalysts for certain chemical processes. This outlook summarizes recent advances and proposes prospective research directions in the design of catalysts and characterizations of FECCs, together with potential challenges.

Automated summary

Single-atom catalysts have attracted increasing attention in heterogeneous catalysis due to their unique electronic properties, but may have limited advantages for reactions that require multiple atomic metallic states or metal-metal bond surface sites. Fully exposed cluster catalysts, as a cross-dimensional extension to the concept of single-atom catalysts, provide diverse surface sites and offer the advantage of maximized atom utilization efficiency. This outlook summarizes recent advances in the design and characterization of cluster catalysts, along with potential challenges.