Visualisation of single atom dynamics and their role in nanocatalysts under controlled reaction environments

TL;DR

This paper presents real-time visualization of individual atom dynamics in gold and platinum nanocatalysts under controlled environments, revealing their roles in catalysis and deactivation processes.

Contribution

It introduces novel environmental STEM techniques to observe single atom behavior in situ, providing new insights into catalytic mechanisms at the atomic level.

Findings

Nanoparticles act as reservoirs of ad-atoms or clusters.

Single atom dynamics influence catalytic activity and deactivation.

Real-time in situ observations reveal atom migration and behavior.

Abstract

Direct real time studies of reacting individual atoms in technologically important gold and platinum nanocatalysts in controlled reducing and oxidising gas environments and operating temperatures using novel environmental scanning transmission electron microscopy (ESTEM) with single atom sensitivity are presented. The direct in situ observations provide new insights into the dynamic behaviour of single atoms which may be important as catalytic active sites as well as migrating as part of deactivation mechanisms. The single atom dynamics reveal that the primary role of nanoparticles in the catalysts is to act as reservoir of ad-atoms or clusters. Possible reaction mechanisms are described briefly