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https://doi.org/10.5194/egusphere-2023-2254
https://doi.org/10.5194/egusphere-2023-2254
13 Oct 2023
 | 13 Oct 2023

Quantum Yields of CHDO above 300 nm

Ernst-Peter Röth and Luc Vereecken

Abstract. The photolysis of mono-deuterated formaldehyde, CHDO, is a critical process in the deuterium-enrichment of stratospheric hydrogen formed from methane. A consistent description of the quantum yields of the molecular and radical channels of the CHDO photolysis is deduced from literature data. The fluorescence measurements of Miller and Lee (1978) provided a first data set to deduce the product quantum yields. An alternative analysis is provided by the measured quantum yield spectrum for the radical channel of the CD2O photolysis by McQuigg and Calvert (1969), which is corrected for wavelength dependency and combined with the CH2O quantum yield spectrum to provide an approximation for CHDO. Both approaches provide consistent results. Finally, the findings of Troe (1984, 2007) enable the specification of the pressure dependence of the quantum yield for CH2O and CD2O and, hence, for CHDO. We find that the radical channel does not show a  pressure dependence, whereas the molecular channel is dominated by tunneling and quenching processes. For modeling purposes, simplified representations are given, and as an example for their application, the altitude dependence of the ratio of J(CHDO HD+CO) and J(CH2O H2+CO) is provided.

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Journal article(s) based on this preprint

28 Feb 2024
Quantum yields of CHDO above 300 nm
Ernst-Peter Röth and Luc Vereecken
Atmos. Chem. Phys., 24, 2625–2638, https://doi.org/10.5194/acp-24-2625-2024,https://doi.org/10.5194/acp-24-2625-2024, 2024
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

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The paper presents the radical and molecular product quantum yields in the photolysis reaction...
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