Flash photolysis study of the CH sub 3 O sub 2 + HO sub 2 reaction between 248 and 573 K

Journal Article · Thu Jan 25 04:00:00 EST 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100365a036· OSTI ID:6646460

Lightfoot, P D; Veyret, B; Lesclaux, R ^[1]

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1. Universite de Bordeaux I, Talence (France)

The kinetics of the reaction CH{sub 3}O{sub 2} + HO{sub 2} {yields} products (1) has been investigated between 248 and 573 K, using the flash photolysis-UV absorption technique. The rate constant, k{sub 1}, was found to be independent of the presence of up to 12.8 Torr of water vapor at 298 K and of pressure between 210 and 760 Torr and can be represented by the Arrhenius expression k{sub 1}/cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} = (4.4 {plus minus} 0.7) {times} 10{sup {minus}13} exp((780 {plus minus} 55)/T). Absolute uncertainties, including experimental scatter and uncertainties in the analysis parameters used to derive k{sub 1}, are estimated to be 32% at 248 K, falling to 26% at 573 K. New results on the HO{sub 2} + HO{sub 2} {yields} H{sub 2}O{sub 2} + O{sub 2} (11) reaction, obtained between 248 and 573 K and 100 and 760 Torr total pressure, are presented, with k{sub 11}/cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} = (3.8 {plus minus} 0.4) {times} 10{sup {minus}13}exp ((580 {plus minus} 32)/T) + (1.2 {plus minus} 0.4) {times} 10{sup {minus}33}(M) exp((1,150 {plus minus} 97)/T). The UV absorption cross sections for HO{sub 2} and CH{sub 3}O{sub 2} are critically reviewed. The rate constant for the reaction of atomic chlorine with methanol, Cl + CH{sub 3}OH {yields} HCl + CH{sub 2}OH (6), was obtained relative to that with methane, Cl + CH{sub 4} {yields} HCl + CH{sub 3} (8). k{sub 6} was independent of temperature, within experimental error, from 248 to 573 K, with k{sub 6}/cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} = (5.3 {plus minus} 1.2) {times} 10{sup {minus}11}. Errors are 1{sigma}.

• OSTI ID: 6646460
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:2; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

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