MNRAS-2008-Goumans-1158-64.pdf (1.77 MB)
Formation of CO2 on a carbonaceous surface: a quantum chemical study
journal contribution
posted on 2023-06-08, 17:18 authored by T P M Goumans, Madeeha A Uppal, Wendy BrownWendy BrownThe formation of CO2 in the gas phase and on a polyaromatic hydrocarbon surface (coronene) via three possible pathways is investigated with density functional theory. Calculations show that the coronene surface catalyses the formation of CO2 on model grain surfaces. The addition of O-3 to CO is activated by 2530 K in the gas phase. This barrier is lowered by 253 K for the Eley-Rideal mechanism and 952 K for the hot-atom mechanism on the surface of coronene. Alternative pathways for the formation of CO2 are the addition of O-3 to the HCO radical, followed by dissociation of the HCO2 intermediate. The O + HCO addition is barrierless in the gas phase and on the surface and is more than sufficiently exothermic to subsequently cleave the H-C bond. The third mechanism, OH + CO addition followed by H removal from the energized HOCO intermediate, has a gas-phase exit barrier that is 1160 K lower than the entrance barrier. On the coronene surface, however, both barriers are almost equal. Because the HOCO intermediate can also be stabilized by energy dissipation to the surface, it is anticipated that for the surface reaction the adsorbed HOCO could be a long-lived intermediate. In this case, the stabilized HOCO intermediate could react, in a barrierless manner, with a hydrogen atom to form H-2 + CO2, HCO2H, or H2O + CO.
History
Publication status
- Published
File Version
- Published version
Journal
Monthly Notices of the Royal Astronomical SocietyISSN
0035-8711Publisher
Wiley-BlackwellExternal DOI
Issue
3Volume
384Page range
1158 - 1164Department affiliated with
- Chemistry Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2014-07-22First Open Access (FOA) Date
2014-07-22First Compliant Deposit (FCD) Date
2014-07-22Usage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC