Catalytic Mechanisms in Metal Clusters

Metal clusters occupy the size regime between single-atom catalysts and larger nanoparticles, exhibiting unique catalytic properties arising from their discrete electronic states, high surface-to-volume ratios and under-coordinated atoms. In heterogeneous catalysis these clusters are often supported on oxides, carbon materials or other substrates that both stabilise specific cluster sizes and modulate electronic structure through interfacial charge transfer. Active sites in clusters can be highly site-specific, with edge and corner atoms differing markedly from those in the core. Dynamic structural changes—such as solid-to-liquid transitions at sub-nanometre scales—further influence reaction energetics, lowering activation barriers in certain pathways. The fine control of cluster nuclearity, composition and support interactions has enabled advances in reactions of global importance, including CO oxidation, selective dehydrogenation, hydrogen evolution and CO₂ hydrogenation to fuels. Understanding these mechanisms paves the way to rational design of catalysts with maximised activity, selectivity and stability under realistic conditions.

Research from Nature Portfolio

Recent studies have advanced scalable synthesis of atomically precise clusters with uniform metal sites. Improved wet-chemistry and cluster-beam methods now yield low-nuclearity clusters reliably deposited on oxide and carbon supports, allowing systematic exploration of how metal–metal bonding and cluster size dictate catalytic properties. Investigations into CO oxidation over mass-selected Pt clusters on non-reducible oxides have shown that under-coordinated Pt atoms at cluster edges become cationic via support interaction, altering oxygen affinity and thereby tuning reaction rates independently of exposed surface area. Computational models combining bond-additivity approaches with support-bond energies now predict activity trends across cluster sizes and supports. Furthermore, ab initio molecular dynamics has revealed that sub-nanometre Au clusters undergo solid-to-liquid phase transitions during reaction turnover, introducing entropic contributions that reduce free-energy barriers. Such dynamic behaviour underscores the importance of coupling structural fluctuations with elementary reaction steps in cluster catalysis.

Catalytic Mechanisms in Metal Clusters publication trend

The graph below shows the total number of articles in catalytic mechanisms in metal clusters across all publications each year (not limited to Nature Index journals).

Technical terms

Metal cluster: An assembly of a few to a few dozen metal atoms whose electronic and geometric structure differs from both single atoms and bulk nanoparticles.

Heterogeneous catalysis: A catalytic process in which the catalyst and reactants exist in different phases, typically solid catalyst and gas or liquid reactants.

Active site: A specific atom or ensemble of atoms on the catalyst surface where reactant molecules adsorb and undergo chemical transformation.

Under‐coordination: A condition in which an atom at a surface or cluster edge has fewer neighbouring atoms than in the bulk, often leading to enhanced reactivity.

Support interaction: Electronic or structural effects arising from contact between a metal cluster and its substrate, influencing cluster stability and catalytic properties.

References

1. Synthetic strategies of supported atomic clusters for heterogeneous catalysis. Nature Communications (2020).
2. CO oxidation activity of non-reducible oxide-supported mass-selected few-atom Pt single-clusters. Nature Communications (2020).
3. Solid-to-liquid phase transitions of sub-nanometer clusters enhance chemical transformation. Nature Communications (2019).
4. Unveiling Inequality of Atoms in Ultrasmall Pt Clusters: Oxygen Adsorption Limited to the Uppermost Atomic Layer. Small Structures (2024).
5. Dynamic Interplay between Copper Tetramers and Iron Oxide Boosting CO2 Conversion to Methanol and Hydrocarbons under Mild Conditions. ACS Sustainable Chemistry & Engineering (2019).