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Kinetic studies of excited singlet oxygen atom O( 1 D) reactions with ethanol
Author(s) -
Zhong Hongtao,
Yan Chao,
Teng Chu C.,
Chen Timothy Y.,
Wysocki Gerard,
Ju Yiguang
Publication year - 2021
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.21474
Subject(s) - chemistry , photodissociation , excited state , reaction rate constant , singlet oxygen , analytical chemistry (journal) , spectroscopy , branching fraction , reaction mechanism , oxygen , photochemistry , kinetics , catalysis , atomic physics , physics , organic chemistry , quantum mechanics , chromatography , biochemistry
The multichannel reaction of excited singlet oxygen atom with ethanol, O( 1 D) + C 2 H 5 OH (1), was studied in a photolysis flow reactor coupled with mid‐infrared Faraday rotation spectroscopy (FRS) and UV‐IR direct absorption spectroscopy (DAS) at 297 K with reactor pressures of 60, 120, and 150 Torr (bath He). The excited singlet oxygen atom was generated through the photolysis of O 3 at 266 nm. The photon flux and O( 1 D) concentrations were determined by in situ actinometry based on O 3 depletion. Temporal profiles of OH and H 2 O were monitored via DAS signals at ca. 3568.62 and 3568.29 cm −1 , while temporal profiles of HO 2 were measured via FRS signals at ca. 1396.90 cm −1 . The branching ratios of the target reaction (1) were determined by fitting temporal profiles to simulations from an in‐house reaction mechanism. Two major reaction channels were identified as CH 3 CHOH + OH and CH 3 O + CH 2 OH, and their branching ratios were determined as 0.46 ± 0.12 and 0.42 ± 0.11, respectively. A specific HO 2 + RO 2 reaction between HO 2 and O 2 CH 2 CH 2 OH (β‐RO 2 ) at the low‐temperature range is estimated in this work as HO 2 + O 2 CH 2 CH 2 OH ⟶ products with a rate constant of 7 × 10 −12 cm 3 molecule −1 s −1 .