Insight into CO2 Dissociation in Plasmas from Numerical Solution of a Vibrational Diffusion Equation

TitleInsight into CO2 Dissociation in Plasmas from Numerical Solution of a Vibrational Diffusion Equation
Publication TypeJournal Article
Year of Publication2017
AuthorsP. Diomede, M.CM van de Sanden, S. Longo
JournalJournal of Physical Chemistry C, The

The dissociation of CO2 molecules in plasmas is a subject of enormous importance for fundamental studies and in view of the recent interest in carbon capture and carbon-neutral fuels. The vibrational excitation of the CO2 molecule plays an important role in the process. The complexity of the present state-to-state (STS) models makes it difficult to find out the key parameters. In this paper we propose as an alternative a numerical method based on the diffusion formalism developed in the past for analytical studies. The non-linear Fokker-Planck equation is solved by the time-dependent diffusion Monte Carlo method. Transport quantities are calculated from STS rate coefficients. The asymmetric stretching mode of CO2 is used as a test case. We show that the method reproduces the STS results or a Treanor distribution depending on the choice of the boundary conditions. A positive drift, whose energy onset is determined by the vibrational to translational temperature ratio, brings molecules from mid-energy range to dissociation. Vibrational-translational energy transfers have negligible effect at the gas temperature considered in this study. The possibility of describing the dissociation kinetics as a transport process provides insight towards the goal of achieving efficient CO2 conversion.





Alternate TitleJ. Phys. Chem. C

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