Ab initio kinetics of OH-initiated oxidation of naphthalene: A comprehensive revisited study

• Published in: Atmospheric environment (1994) 2024-04, Vol.322, p.120342, Article 120342
• Main Authors: Nguyen, Loc T., Mai, Tam V.-T., Tran, Uyen N.-P., Hoang, Gia-Huy L., Huynh, Lam K.
• Format: Article
• Language: English
• Subjects: Condensed phase; Gas phase; Kinetic mechanism; Naphthalene; Toxicity
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2024.120342

Naphthalene, the most prevalent and smallest member of the Polycyclic Aromatic Hydrocarbons (PAHs) family, has garnered significant scientific attention for its harmful environmental impacts and those of its degradation products. In this work, we comprehensively recharacterized the gas-phase reaction of naphthalene with OH radicals in a wide range of conditions (T = 200–2000 K &P = 0.76–7600 Torr), covering both atmospheric and combustion chemistry. Within the Rice–Ramsperger–Kassel–Marcus (RRKM)-based master equation framework, the detailed kinetic model was constructed on the potential energy surface explored at the ROCBS-QB3//M06–2X/aug-cc-pVTZ level of theory. Our model not only helps to resolve the existing large discrepancy (up to ∼1000 times) among the previously reported rate constants but also reveals mechanistic insights, including time-resolved species profiles and product distribution, for naphthalene transformation. It is shown that although naphthalene cannot be considered a persistent organic compound (POP) due to its rapid reaction with OH radicals, its chemical conversion can generate harmful substances such as O3 and carcinogenic derivatives. Also, the detailed conversion of naphthalene in water was investigated for the first time, revealing that naphthalene and its important degradation products pose a significant danger to aquatic life as hazardous pollutants. [Display omitted]