7–10 Nov 2022
Europe/Berlin timezone

New insights on the ozone formation reaction

Not scheduled
20m

Speaker

Marjan Mirahmadi (Fritz-Haber-Institut der Max-Planck-Gesellschaft)

Description

Absorbing UV radiation, ozone (O$_3$) that exists in the stratosphere protects life on Earth. Moreover, it plays a crucial role in Earth's temperature balance. In contrast, tropospheric ozone is considered an important greenhouse gas and air pollutant. However, despite its importance and decades of research, the reaction leading to ozone formation is not fully understood due to its complexity. Here, we develop a theoretical approach to model the ozone formation through direct (without invoking the existence of an intermediate complex) ternary recombination reactions O + O$_2$ + M $\rightarrow$ O$_3$ + M where M can be Ar, N$_2$ or O$_2$. In particular, we have applied the method to ternary collisions O+O$_2$+Ar due to the extensive availability of experimental data for comparison. Our formalism, based on classical trajectory calculations [1], allows having a fully ab initio and pressure-independent rate for ozone formation. Accordingly, thermally-averaged rates were derived for temperatures $50$-$900$K. As a result, it is found that the majority of O$_3$ molecules formed initially are weakly bound. In addition, accounting for the process of vibrational quenching of the nascent population, a good agreement with available experimental data for temperatures $100$-$900$K is obtained [2].

[1] J. Pérez-Ríos, S. Ragole, J. Wang, and C. H. Greene, J. Chem. Phys. 140, 044307 (2014).

[2] M. Mirahmadi, J. Pérez-Ríos, O. Egorov, V. Tyuterev, and V. Kokoouline, Phys. Rev. Lett. 128, 108501 (2022).

Abstract Number (department-wise) MP 12
Department MP (Meijer)

Primary author

Marjan Mirahmadi (Fritz-Haber-Institut der Max-Planck-Gesellschaft)

Co-authors

Jesus Perez Rios (Department of molecular Physics, Fritz Haber Institute of the Max Planck Society) Oleg Egorov (Quamer Laboratory, Tomsk State University) Vladimir Tyuterev (Groupe de Spectrometrie Mol´eculaire et Atmospherique, University of Reims Champagne-Ardenne) Viatcheslav Kokoouline (Department of Physics, University of Central Florida)

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