Capturing Nanoparticle Transformation Dynamics with the OneView IS Camera

The OneView^® IS camera is the quickest and most high-performance fiber-coupled camera in Gatan’s portfolio. It is capable of displaying and saving 16 MP images to disk at a rate of up to 25 fps, allowing the close observation of dynamic details as part of in-situ transmission electron microscope (TEM) experiments.

Context

The interface between reducible oxide supports and metal catalyst nanoparticles is a key factor in their catalytic functionality. This interface has the potential to encourage specific nanoparticle orientations while limiting sintering and particle coalescence.

The atomic-scale imaging of supported nanoparticles has historically been a rare, challenging achievement in an operational environment. The experiment presented here aims to directly image a nanoparticle structure over time, facilitating the detailed analysis of the sample’s structure and dynamics as it is heated in oxygen.

Materials and Methods

The CeO₂-supported Au nanoparticles investigated here have been prepared using DENSsolutions’ Wildfire heating chip. They were later observed with an image-corrected FEI Titan ETEM operating at 300 kV. The sample was heated to a temperature of 700 °C in 4.5 Pa O₂.

Data was recorded on a continuous basis using a OneView IS camera working at 5 fps. This was recorded for a total of 318 frames, as detailed in the referenced studies.^1,2

 Figure 1. Three frames from a continuously recorded video showing two crystalline orientations and a non-crystalline phase. The nanoparticle is non-crystalline about 32% of the ~1-minute video plus switches from between crystalline and non-crystalline states 16 times. The full video can be watched here: https://www.rsc.org/suppdata/c9/nr/c9nr02731a/c9nr02731a1.gif Image Credit: Gatan Inc.

Summary

A video recording of this Au nanoparticle demonstrated frequent melting and recrystallization. Two well-defined relationships were also noted between the support and the crystalline Au lattice.

These features highlight the dynamic nature of this catalyst as it is heated to near its melting temperature, as well as the support’s role in determining its nanoparticle orientation.

References

1. Liu, P. et al. Nanoscale 11, 11885–11891 (2019). https://doi.org/10.1039/C9NR02731A
2. Liu, P. et al. J. Phys. Mater. 3, 024009 (2020). https://doi.org/10.1088/2515-7639/ab82b4

This information has been sourced, reviewed and adapted from materials provided by Gatan Inc.

For more information on this source, please visit Gatan Inc.