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Updated: Sep 12, 2025
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Performing In Situ Closed-Cell Gas Reactions in the Transmission Electron Microscope
Published on: July 24, 2021
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Using precise gas exposures to resolve surface site filling in diffuse reflectance infrared Fourier transform
Audrey Dannar1, Hadley Nunn1,2, Christopher R O'Connor1
1Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA. christianreece@fas.harvard.edu.
Chemical Communications (Cambridge, England)
|August 8, 2025
Summary
We developed an affordable Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) system for precise pressure control. This system allows detailed study of catalytic reactions, like CO on Pd/Al2O3, under varying pressures.
Area of Science:
- Surface science and catalysis research.
- Development of advanced spectroscopic techniques.
Background:
- Precise control of reaction conditions is crucial for understanding surface chemistry.
- Existing Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) systems can be complex and expensive.
Purpose of the Study:
- To describe the assembly of a cost-effective DRIFTS system.
- To enable precise pressure control in a DRIFTS cell, from high vacuum to atmospheric pressure.
- To demonstrate the system's utility in studying catalytic reactions.
Main Methods:
- Assembly of a custom DRIFTS cell with pressure control capabilities using accessible components.
- Utilizing Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) for in-situ analysis.
- Adsorption and reaction of carbon monoxide (CO) over a palladium on alumina (Pd/Al2O3) catalyst.
Main Results:
- Successfully assembled a DRIFTS system with pressure control from <10^-6 Torr to atmospheric pressure.
- Observed pressure, temperature, and reaction-dependent preferential binding of CO to adsorption sites on the Pd/Al2O3 catalyst.
- Demonstrated the system's capability to provide insights into catalytic mechanisms.
Conclusions:
- The developed DRIFTS system offers a practical and affordable solution for in-situ surface science studies.
- The system facilitates detailed investigation of catalytic processes under a wide range of pressures.
- This work provides a foundation for further studies on heterogeneous catalysis and surface interactions.
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