Skip to main content
SearchLoginLogin or Signup

New Insights into Catalytic Chlorine Oxidation of CO in the Venus Mesosphere

Presentation #406.09 in the session Venus (Poster + Lightning Talk)

Published onOct 23, 2023
New Insights into Catalytic Chlorine Oxidation of CO in the Venus Mesosphere

Analogous to the Earth’s atmosphere, catalytic chemistry plays fundamental roles in controlling the atmospheric composition of Venus. The CO2 cycle is the dominant chemical cycle above Venus’ clouds, however we still do not understand the conversion of CO to CO2 in Venus’ atmosphere. In particular, models are unable to reproduce the observed CO:O2 ratios. Currently, models of O2 abundance greatly exceed the observed upper limit. The solution may lie in refining the role of Cl as an effective catalyst that recycles O2 as it converts CO into CO2 through Cl + CO ↔ ClCO, ClCO + O2 → ClC(O)O2, ClC(O)O2 + X → CO2 + Cl + Products, (where X = e.g., ClC(O)O2, Cl, NO, SO). As shown, for every CO/O2 lost, a chlorine atom is recycled, thus requiring much less O2 to oxidize CO into CO2. Despite the long-recognized importance of ClOx reactions in the atmospheric composition on Venus, there is a paucity of chemical kinetic data that is utilized by planetary models. Here, we will present recent laboratory results focused on the gas phase chemical kinetics of the ClCO radical. We have recorded, for the first time, the UV/Vis spectrum of the ClCO radical. Additionally, we have new calculations for the ClCO equilibrium constant and ClCO + O2 reaction, which we will compare to current literature data. The possible implications and impacts for the Venus mesosphere will be discussed.

No comments here