Reanalysis of Rate Data for the Reaction CH3 + CH3 → C2H6 Using Revised Cross Sections and a Linearized Second-Order...

Area of Science:

• Chemical Kinetics
• Physical Chemistry
• Atmospheric Chemistry

Background:

• The CH3 + CH3 reaction is fundamental in combustion and atmospheric chemistry.
• Previous studies had inaccuracies in absorption coefficients, necessitating re-evaluation.

Purpose of the Study:

• To correct and refine rate coefficients for the CH3 + CH3 reaction.
• To develop and validate a master equation model for accurate kinetic predictions.

Main Methods:

• Developed a detailed model for the CH3 B̃(2)A1' (3s)-X̃(2)A2″ transition.
• Employed a master equation (ME) model with matrix diagonalization and inverse Laplace transformation.
• Utilized the Levenberg-Marquardt algorithm for fitting experimental data.

Main Results:

• Corrected rate coefficients for the CH3 + CH3 reaction from 300-900 K.
• Obtained a high-pressure limit of k∞(T) = 5.76 × 10(-11)(T/298 K)(-0.34) cm(3) molecule(-1) s(-1).
• The model successfully fitted experimental data across a wide temperature range (300-2000 K).

Conclusions:

• The refined rate coefficients and high-pressure limit provide a more accurate understanding of the CH3 + CH3 reaction.
• The developed master equation model is robust for predicting kinetic parameters.
• Results align well with existing theoretical predictions, enhancing confidence in the findings.