Development of a Robust Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) Cell for Elucidating...

Area of Science:

• Catalysis
• Spectroscopy
• Plasma Science

Background:

• Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is crucial for understanding plasma catalysis.
• Conventional DRIFTS cells struggle with unstable discharges and do not mimic practical reactors like dielectric barrier discharge (DBD) systems.

Purpose of the Study:

• To develop a novel dome-type DRIFTS flow cell for stable and accurate plasma catalysis analysis.
• To investigate the reaction mechanisms of plasma catalytic CO2 methanation using the new cell.

Main Methods:

• Design and implementation of a dome-type DRIFTS flow cell.
• Operando DRIFTS studies of CO2 methanation over a Ni/MgAlOx catalyst under pulsed plasma excitation.
• Analysis of plasma characteristics and IR signals for stability and fidelity.

Main Results:

• The dome cell demonstrated stable operation (>1 h) and accurately emulated DBD reactor conditions.
• Operando DRIFTS revealed formate hydrogenation as the rate-determining step in CO2 methanation via the Langmuir-Hinshelwood mechanism.
• A minor contribution from Eley-Rideal/Langmuir-Rideal mechanisms was observed under plasma conditions.

Conclusions:

• The developed dome-type DRIFTS cell is a robust platform for in situ/operando diagnostics in plasma catalysis.
• Mechanistic insights into CO2 methanation provide a foundation for catalyst and system optimization in electrified technologies.