Scientists from the ZIOC developed the concept of 4D catalysis and were able to trace the evolution of specific particles of a metal catalyst during the catalytic process

Catalysis by supported metal nanoparticles is of key importance for modern organic synthesis in science and industry. The properties of these catalysts can be finely tuned by controlling the composition, size, and morphology of the nanoparticles. The most common catalysts of this type are palladium nanoparticles. To study the behavior of catalysts based on nanoparticles, electron microscopy is widely used, which is usually carried out before and after the catalytic reaction. It is generally accepted that it is rather difficult to see the same catalyst microregion before and after the reaction. For this reason, random areas of the catalyst surface are usually examined, as a result of which inaccurate or even wrong conclusions are often drawn.

Scientists from the Laboratory of Metal Complex and Nanoscale Catalysts of the Zelinsky Institute are conducting active research aimed at a detailed study of the mechanisms of catalytic reactions. In one of their latest works, the researchers proposed an approach to the spatially localized characterization of supported catalysts in the course of a reaction, i.e. managed to trace the evolution of specific metal catalyst particles over the reaction time using the example of Mizoroki-Heck and Suzuki-Miyaura cross-couplings. The dynamic behavior of individual palladium atoms and nanoparticles in cross-coupling reactions was recorded with nanometer accuracy due to the exact localization of catalytic sites. It was shown that individual palladium atoms were washed out of the support into the solution under the action of a catalytic system, where they exhibit an extremely high catalytic activity compared to surface metal nanoparticles. The latter changed their shape and could move along the surface of the substrate, which was fixed by processing the images of the array of nanoparticles with a neural network and combining them using automatically determined key points. The study using electron microscopy, supported by machine learning analysis, brings scientists as close as possible to the answer to the question: “How do catalytic reactions actually proceed?”.

The research was carried out in V.P. Ananikov Laboratory and published in the Journal of the American Chemical Society, impact factor = 16.383.

Source:

Alexey S. Galushko, Daniil A. Boiko, Evgeniy O. Pentsak, Dmitry B. Eremin, and Valentine P. Ananikov Time-Resolved Formation and Operation Maps of Pd Catalysts Suggest a Key Role of Single Atom Centers in Cross-Coupling // J. Am. Chem. Soc., 2023, 145, 16, 9092–9103. DOI: 10.1021/jacs.3c00645. https://dx.doi.org/10.1021/jacs.3c00645