Novel sample preparation for operando TEM of catalysts

Area of Science:

• Materials Science
• Chemical Engineering
• Catalysis Science

Background:

• Operando transmission electron microscopy (TEM) is crucial for studying gas phase catalysis in real-time.
• Traditional methods face limitations in catalyst loading and in-situ analysis.
• Developing advanced sample preparation techniques is essential for enhanced operando studies.

Purpose of the Study:

• To develop a novel sample preparation method for operando TEM of gas phase catalysis.
• To enable quantitative analysis of gas phase products during in-situ catalytic reactions.
• To overcome challenges in imaging catalyst particles within the TEM environment.

Main Methods:

• Fabrication of a porous Pyrex-fiber pellet TEM sample.
• Utilizing a Gatan furnace-type tantalum heating holder for high catalyst loading.
• Employing electron energy loss spectroscopy (EELS) and residual gas analysis (RGA) for product monitoring.
• Integrating a metal grid for improved imaging of catalyst particles.

Main Results:

• Successful preparation of a TEM sample facilitating operando gas phase catalysis.
• Quantitative determination of gas phase products at elevated temperatures.
• Demonstration of a method to image catalyst particles on a metal grid while analyzing conversion from a catalyst pellet.
• Confirmation of well-mixed gas conditions within the environmental TEM cell.

Conclusions:

• The developed method significantly enhances the capability for in-situ operando TEM studies of gas phase catalysis.
• This approach allows for detailed investigation of catalytic mechanisms and product formation.
• The combined use of a catalyst pellet and imaging grid offers a robust strategy for correlating structure and activity.