Ex situ transmission electron microscopy: a fixed-bed reactor approach

Area of Science:

• Materials Science
• Chemical Engineering
• Catalysis Research

Background:

• Heterogeneous catalysis is crucial for many industrial processes.
• Understanding catalyst deactivation and morphology changes is key to improving catalyst performance.
• Current methods often lack the ability to study catalysts under true reaction conditions.

Purpose of the Study:

• To design and construct a novel fixed-bed reactor system for *ex situ* transmission electron microscopy (TEM) studies.
• To enable time-resolved monitoring of catalyst morphology under realistic process conditions.
• To facilitate the investigation of catalyst behavior without requiring specialized TEM modifications.

Main Methods:

• A fixed-bed reactor was designed and built to house a TEM grid at its exit.
• The reactor allows controlled transfer of the TEM grid into and out of the microscope under an inert environment.
• The system was tested using the oxidation of supported copper nanoparticles (20-80 nm).

Main Results:

• The developed facility successfully exposed TEM samples to controlled process conditions.
• Time-resolved observations of catalyst morphology changes were achieved.
• The oxidation of copper particles demonstrated the system's utility for studying catalyst evolution.

Conclusions:

• The independent fixed-bed reactor system provides a versatile platform for *ex situ* TEM studies of heterogeneous catalysts.
• This approach allows for detailed analysis of catalyst structural evolution under industrially relevant conditions.
• The method minimizes disruption to TEM availability and enables long-term catalyst research.