Kinetic study of reaction with interest to atmospheric and combustion chemistry by a simultaneous detection of OH and RO2 radicals coupled to laser photolysis

Title and thesis summary

Kinetic study of reactions with interest to atmospheric chemistry by simultaneous detection of OH and RO2 radicals coupled to laser photolysis

After determining the infrared spectrum of OH, HO₂ and CH₃O₂ radicals in the near infrared region and the absorption cross-sections of few selected lines, four systems were studied with the above mentioned techniques: CH₃O₂ + OH, C₂H₅O₂ + OH, C₃H₇O₂ + OH and C₄H₉O₂ + OH. The rate constant and the HO₂ yield of the four reactions were determined. In addition, the rate constants of few secondary reactions such as CH₃O + HO₂, CH₃O ₊ CH₃O or OH + HO₂ have been determined.

Thesis supervisor : Christa Fittschen et Coralie Schoemaecker
Referees : David Rowley et Geoffrey Tyndall
Examiners : Dwayne Heard, Yoshizumi Kajii, Votava Ondrej, Huet Thérèse et Jimenez Elena

Financing : Région Nord-Pas-de-Calais / Labex CaPPA

Publications

i) E. Assaf and C. Fittschen, “Cross Section of OH Radical Overtone Transition near 7028 cm-1 and Measurement of the Rate Constant of the Reaction of OH with HO2 Radicals,” J. Phys. Chem. A, vol. 120, no. 36, pp. 7051–7059, Sep. 2016.
http://pubs.acs.org/doi/abs/10.1021/acs.jpca.6b06477

(ii) E. Assaf, B. Song, A. Tomas, C. Schoemaecker, and C. Fittschen, “Rate Constant of the Reaction between CH3O2 Radicals and OH Radicals Revisited,” J. Phys. Chem. A, vol. 120, no. 45, pp. 8923–8932, Nov. 2016.
http://pubs.acs.org/doi/abs/10.1021/acs.jpca.6b07704

(iii) E. Assaf, L. Sheps, L. Whalley, D. Heard, A. Tomas, C. Schoemaeker, C. Fittschen, “The Reaction between CH3O2 and OH Radicals: Product Yields and Atmospheric Implications,” Environmental Science & Technology, vol. 51, no. 4, pp. 2170–2177, Feb. 2017.
http://pubs.acs.org/doi/abs/10.1021/acs.est.6b06265

(iv)    D. Liu, F. Khaled, B. R. Giri, E. Assaf, C. Fittschen, and A. Farooq, “H-Abstraction by OH from Large Branched Alkanes: Overall Rate Measurements and Site-Specific Tertiary Rate Calculations,” J. Phys. Chem. A, vol. 121, no. 5, pp. 927–937, Feb. 2017.
http://pubsdc3.acs.org/doi/abs/10.1021/acs.jpca.6b10576

(v)      C. Fittschen, E. Assaf, and L. Vereecken, “Experimental and Theoretical Investigation of the Reaction NO + OH + O2→ HO2 + NO2,” J. Phys. Chem. A, vol. 121, no. 24, pp. 4652–4657, Jun. 2017.
http://pubs.acs.org/doi/abs/10.1021/acs.jpca.7b02499

(vi)    E. Assaf, S. Tanaka, Y. Kajii, C. Schoemaecker, and C. Fittschen, “Rate Constants of the Reaction of C2–C4 Peroxy Radicals with OH Radicals,” Chemical Physics Letters, vol. 684, pp. 245–249, Sep. 2017.
http://www.sciencedirect.com/science/article/pii/S000926141730619X

(vii)   E. Assaf, O. Asvany, O. Votava, S. Batut, C. Schoemaecker, and C. Fittschen, “Measurement of line strengths in the à 2A’ ← 2A” transition of HO2 and DO2,” Journal of Quantitative Spectroscopy and Radiative Transfer, vol. 201, pp. 161–170, Nov. 2017.
http://www.sciencedirect.com/science/article/pii/S0022407317303722

Oral and posters presentation

Future

Emmanuel Assaf is currently doing a postdoc at PC2A laboratory,

financed by the regional project Climibio