Structural evolution behaviors of oxide-supported metal nanoparticles: a brief review

The development of new heterogeneous catalysts with well-defined nanostructures has been the focus of the chemical industry and academia. Oxide-supported metal nanoparticles (NPs) often undergo dynamic structural evolutions depending upon their preparation and reaction conditions. Clarifying the structural evolution behaviors of these metal NPs is an essential prerequisite for understanding their significant influence on catalytic activities and the rational design of high-performance heterogeneous catalysts. This review aims to delineate the advancements in the last two decades in the structural evolutions of oxide-supported NPs, with a particular focus on establishing the correlation between fundamental energetic descriptors and specific evolution pathways. We discuss how advanced in situ characterization techniques and computational simulations have uncovered the mechanisms by which the temperature, NP size, oxide reducibility, and adsorbates govern the NP stability. Generally, the thermodynamic instability of NPs can give rise to sintering, variations in the metal-oxide interactions can cause encapsulation, and the reactive adsorbates can result in the structural fluctuations of NPs or single-atom (SA) disintegration. Finally, the challenges and opportunities for further in-depth investigations on the structural evolution issues of oxide-supported metal NPs are elucidated.