Detection and Identification of the Keto-Hydroperoxide (HOOCH 2 OCHO) and Other Intermediates during Low-Temperature Oxidation of Dimethyl Ether

Handle URI:
http://hdl.handle.net/10754/566096
Title:
Detection and Identification of the Keto-Hydroperoxide (HOOCH 2 OCHO) and Other Intermediates during Low-Temperature Oxidation of Dimethyl Ether
Authors:
Moshammer, Kai; Jasper, Ahren W.; Popolan-Vaida, Denisia M.; Lucassen, Arnas; Diévart, Pascal; Selim, Hatem; Eskola, Arkke J.; Taatjes, Craig A.; Leone, Stephen R.; Sarathy, Mani ( 0000-0002-3975-6206 ) ; Ju, Yiguang; Dagaut, Philippe; Kohse-Höinghaus, Katharina; Hansen, Nils
Abstract:
In this paper we report the detection and identification of the keto-hydroperoxide (hydroperoxymethyl formate, HPMF, HOOCH2OCHO) and other partially oxidized intermediate species arising from the low-temperature (540 K) oxidation of dimethyl ether (DME). These observations were made possible by coupling a jet-stirred reactor with molecular-beam sampling capabilities, operated near atmospheric pressure, to a reflectron time-of-flight mass spectrometer that employs single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation. On the basis of experimentally observed ionization thresholds and fragmentation appearance energies, interpreted with the aid of ab initio calculations, we have identified HPMF and its conceivable decomposition products HC(O)O(O)CH (formic acid anhydride), HC(O)OOH (performic acid), and HOC(O)OH (carbonic acid). Other intermediates that were detected and identified include HC(O)OCH3 (methyl formate), cycl-CH2-O-CH2-O- (1,3-dioxetane), CH3OOH (methyl hydroperoxide), HC(O)OH (formic acid), and H2O2 (hydrogen peroxide). We show that the theoretical characterization of multiple conformeric structures of some intermediates is required when interpreting the experimentally observed ionization thresholds, and a simple method is presented for estimating the importance of multiple conformers at the estimated temperature (∼100 K) of the present molecular beam. We also discuss possible formation pathways of the detected species: for example, supported by potential energy surface calculations, we show that performic acid may be a minor channel of the O2 + CH2OCH2OOH reaction, resulting from the decomposition of the HOOCH2OCHOOH intermediate, which predominantly leads to the HPMF. © 2015 American Chemical Society.
KAUST Department:
Chemical Science Program; Clean Combustion Research Center; Chemical and Biological Engineering Program; Physical Sciences and Engineering (PSE) Division
Publisher:
American Chemical Society (ACS)
Journal:
The Journal of Physical Chemistry A
Issue Date:
16-Jul-2015
DOI:
10.1021/acs.jpca.5b00101
Type:
Article
ISSN:
1089-5639; 1520-5215
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; Chemical and Biological Engineering Program; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorMoshammer, Kaien
dc.contributor.authorJasper, Ahren W.en
dc.contributor.authorPopolan-Vaida, Denisia M.en
dc.contributor.authorLucassen, Arnasen
dc.contributor.authorDiévart, Pascalen
dc.contributor.authorSelim, Hatemen
dc.contributor.authorEskola, Arkke J.en
dc.contributor.authorTaatjes, Craig A.en
dc.contributor.authorLeone, Stephen R.en
dc.contributor.authorSarathy, Manien
dc.contributor.authorJu, Yiguangen
dc.contributor.authorDagaut, Philippeen
dc.contributor.authorKohse-Höinghaus, Katharinaen
dc.contributor.authorHansen, Nilsen
dc.date.accessioned2015-08-12T09:28:05Zen
dc.date.available2015-08-12T09:28:05Zen
dc.date.issued2015-07-16en
dc.identifier.issn1089-5639en
dc.identifier.issn1520-5215en
dc.identifier.doi10.1021/acs.jpca.5b00101en
dc.identifier.urihttp://hdl.handle.net/10754/566096en
dc.description.abstractIn this paper we report the detection and identification of the keto-hydroperoxide (hydroperoxymethyl formate, HPMF, HOOCH2OCHO) and other partially oxidized intermediate species arising from the low-temperature (540 K) oxidation of dimethyl ether (DME). These observations were made possible by coupling a jet-stirred reactor with molecular-beam sampling capabilities, operated near atmospheric pressure, to a reflectron time-of-flight mass spectrometer that employs single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation. On the basis of experimentally observed ionization thresholds and fragmentation appearance energies, interpreted with the aid of ab initio calculations, we have identified HPMF and its conceivable decomposition products HC(O)O(O)CH (formic acid anhydride), HC(O)OOH (performic acid), and HOC(O)OH (carbonic acid). Other intermediates that were detected and identified include HC(O)OCH3 (methyl formate), cycl-CH2-O-CH2-O- (1,3-dioxetane), CH3OOH (methyl hydroperoxide), HC(O)OH (formic acid), and H2O2 (hydrogen peroxide). We show that the theoretical characterization of multiple conformeric structures of some intermediates is required when interpreting the experimentally observed ionization thresholds, and a simple method is presented for estimating the importance of multiple conformers at the estimated temperature (∼100 K) of the present molecular beam. We also discuss possible formation pathways of the detected species: for example, supported by potential energy surface calculations, we show that performic acid may be a minor channel of the O2 + CH2OCH2OOH reaction, resulting from the decomposition of the HOOCH2OCHOOH intermediate, which predominantly leads to the HPMF. © 2015 American Chemical Society.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleDetection and Identification of the Keto-Hydroperoxide (HOOCH 2 OCHO) and Other Intermediates during Low-Temperature Oxidation of Dimethyl Etheren
dc.typeArticleen
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentChemical and Biological Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalThe Journal of Physical Chemistry Aen
kaust.authorSelim, Hatemen
kaust.authorSarathy, Manien
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