Speaker
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) |
