Restructuring effects of the chemical environment in metal nanocatalysis and single-atom catalysis

Metal-based heterogeneous catalysts mostly consist of supported nanoparticles of a few nanometers in size, since these objects provide a good compromise between exposed active surface area and structural stability. However, far from being static, heterogeneous catalysts constantly evolve under reaction conditions, thereby creating and removing surface sites in response to their gaseous or liquid reactive environment. Modern ex situ and in situ investigations have shown that nanocatalysts at work can face a number of deep restructuring phenomena, such as morphological change, compound formation, segregation, leaching, as well as redispersion and other metalsupport interaction effects. Recently emerging single-atom catalysts are-like subnanometric clusters-especially sensitive to their chemical environment. Using examples from the recent literature with a particular emphasis on operando characterization studies, this article reviews the main dynamic effects induced by the reaction medium on nanocatalysts (including nanoalloy catalysts) and single-atom catalysts.

Automated summary

Metal-based heterogeneous catalysts are typically composed of supported nanoparticles a few nanometers in size, balancing active surface area with structural stability. These catalysts constantly evolve under reaction conditions, experiencing phenomena such as morphological changes, compound formation, segregation, leaching, and other interaction effects with the support material. Single-atom catalysts, particularly sensitive to their chemical environment, have also emerged as a new area of study in catalysis research.