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Computational Investigation of the Reaction Kinetics between 2-Hydroxyethyl Radical and Nitrogen Dioxide
Qian Zhao1, Chunyu Wang2, Yingjia Zhang2
1Department of Fire Protection Engineering, Southwest Jiaotong University, Chengdu, Sichuan 611756, China.
The Journal of Physical Chemistry. A
|November 7, 2025
Summary
This study details the reaction kinetics between the 2-hydroxyethyl radical and nitrogen dioxide (NO2). New theoretical calculations provide accurate rate coefficients, improving combustion models.
Area of Science:
- Chemical kinetics
- Combustion chemistry
- Theoretical chemistry
Background:
- The 2-hydroxyethyl radical is a key intermediate in hydrocarbon combustion.
- Nitrogen oxides (NOx) influence its reaction pathways.
- Existing kinetic models use unvalidated extrapolated data.
Purpose of the Study:
- To theoretically investigate the reaction kinetics of the 2-hydroxyethyl radical with nitrogen dioxide (NO2).
- To provide accurate temperature- and pressure-dependent rate coefficients for this reaction.
- To assess the impact of these new kinetics on combustion models.
Main Methods:
- High-level theoretical calculations using CCSD(T)/CBS//M06-2X/aug-cc-pVDZ.
- Microcanonical variational transition state theory.
- Rice-Ramsperger-Kassel-Marcus/Master Equation calculations.
Main Results:
- Determined the dominant reaction pathway: radical carbon attack on nitrogen, forming CH2O + CH2NOOH.
- Calculated temperature- and pressure-dependent rate coefficients.
- Incorporating these results showed negligible impact on major species evolution in kinetic models.
Conclusions:
- The theoretical investigation provides crucial kinetic data for the ĊH2CH2OH + NO2 reaction.
- Current combustion models are largely unaffected by these findings for major species.
- Refinement of NO2 + NO2 kinetics is recommended for improved model accuracy.
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