In-situ X-Ray Absorption Near Edge Structure Spectroscopy of a Solid Catalyst using a Laboratory-Based Set-up

Area of Science:

• Materials Science
• Catalysis
• Spectroscopy

Background:

• Solid catalysts are crucial for industrial chemical processes like Fischer-Tropsch Synthesis (FTS).
• Understanding catalyst behavior under reaction conditions is essential for optimizing performance.
• Existing synchrotron-based methods can be limited for long-term in-situ studies.

Purpose of the Study:

• To present a novel laboratory-based X-ray Absorption Near Edge Structure (XANES) Spectroscopy setup.
• To enable long-term in-situ characterization of solid catalysts at relevant reaction conditions (temperature and pressure).
• To demonstrate the setup's utility using a cobalt/titanium dioxide (Co/TiO2) FTS catalyst.

Main Methods:

• Development and implementation of an in-situ laboratory XANES spectroscopy system.
• Performing long-term (200 hours) Fischer-Tropsch Synthesis (FTS) experiments on a Co/TiO2 catalyst.
• Analysis of catalyst speciation and stability under high temperature (523 K) and pressure (5 bar) conditions.

Main Results:

• The Co/TiO2 catalyst primarily consisted of supported cobalt metal nanoparticles.
• A small fraction of inactive cobalt(II) titanate was observed.
• No re-oxidation of cobalt metal nanoparticles was detected during 200 hours of FTS operation.

Conclusions:

• The developed laboratory XANES setup is suitable for long-term in-situ catalyst studies.
• Cobalt metal is confirmed as the stable and active phase for FTS on the studied Co/TiO2 catalyst.
• The catalyst maintained its active metallic cobalt state throughout the extended reaction period.