Transient Catalytic Reaction Analysis Through Signal Defragmentation.

Area of Science:

• Catalysis and Reaction Engineering
• Surface Science
• Analytical Chemistry

Background:

• Temporal Analysis of Products (TAP) pulse response is key for studying catalytic function and kinetics.
• Complex mass spectrometry fragmentation patterns hinder precise quantification of transient gas flux data in TAP experiments.

Purpose of the Study:

• To demonstrate a standard defragmentation method for deconvoluting transient TAP signals.
• To maintain temporal resolution during signal analysis.
• To enable accurate quantification of reactant/product concentrations and reaction rates.

Main Methods:

• Constructing a fragmentation matrix using calibration gas fluxes.
• Applying non-negative least squares regression for defragmentation at each time point.
• Validating the method with virtual data, control experiments, and propane dehydrogenation.

Main Results:

• The defragmentation method effectively deconvolutes complex TAP signals.
• Accurate time-dependent concentrations and rates were determined for propane dehydrogenation.
• The method revealed an induction period with full oxidation, followed by partial reduction, coking, and propylene production.

Conclusions:

• The developed defragmentation technique offers a practical solution for accurate analysis of transient mass spectrometry data.
• This approach enhances the understanding of catalyst-reaction dynamics in various transient experiments.
• It is broadly applicable for detailed kinetic studies of catalytic processes.