Keeping atoms apart in advances catalysts


Catalysis is becoming increasingly relevant in a wide range of applications, including green energy, automotive emissions, chemical refining, and more. The catalyst is a substance capable of accelerating chemical reactions, and among its more relevant parameters are efficiency and duration. In this regard, single-atom catalysts have remarkable advantages, and experimental techniques and practical approaches have been developed to optimise the catalyst utilisation to improve the understanding of nanoparticle dynamic changes throughout the catalyst lifetime. A common problem in this sense is to prevent the aggregation of metal atoms to metal nanoparticles which will result in a loss of efficiency.

Figure 1: Reversible changes of Pt morphology on CeO2(111) single-atom catalyst substrate as a function of the reaction atmosphere. At reducing conditions, Pt nanoparticles are formed (a). At oxidizing conditions, Pt nanoparticles disintegrate into to Pt single-atoms at ceria step-edges (b). STM micrographs, 30 x 30 nm2. (c, d): theoretical model of the process. Adapted with permission from M. Farnesi Camellone et al., ACS Catal. 12, 4859 (2022). Copyright 2022 American Chemical Society.

Dr. Stefano Fabris (CNR-IOM), Dr. Josef Mysliveček (Charles University), and colleagues performed dedicated surface science experiments and calculations revealing the dynamic character of platinum (Pt) load on a cerium oxide (CeO2) support. With such work, the authors aimed to identify general conditions under which metal nanoparticle catalysts on single-atom catalyst substrates can be optimised and operated stably. The experiments were performed at the Materials Science Beamline available at the Czech CERIC Partner Facility at the Elettra synchrotron in Trieste.

The authors demonstrated that for long-term activity in catalytic applications, single-atom catalyst substrates allow efficient redispersion of the supported metal nanoparticles. This possibility is particularly appealing for applications such as automotive catalysts allowing for the abatement of pollutants’ emissions such as carbon monoxide (CO) and nitrogen oxides (NOX).


Adatom and Nanoparticle Dynamics on Single-Atom Catalyst Substrates. Farnesi Camellone M., Dvořák F., Vorokhta M., Tovt A., Khalakhan I., Johánek V., Skála T., Matolínová I., Fabris S., Mysliveček J., ACS Catal. 12 (9), 2022


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