Theoretical Mechanistic and Kinetic Studies on Homogeneous Gas-Phase Formation of Polychlorinated Naphthalene from 2-Chlorophenol as Forerunner

International Journal of Molecular Sciences

Fei Xu¹  Ruiming Zhang²  Yunfeng Li²  Qingzhu Zhang²  Wenxing Wang² 

[1] Environment Research Institute, Shandong University, Jinan 250100, China;

关键词: 2-chlorophenol;    reaction mechanism;    rate constants;    formation of polychlorinated naphthalene;    and theoretical mechanistic and kinetic study;   

DOI  :  10.3390/ijms161025641

来源: mdpi

【 摘 要 】

Polychlorinated naphthalenes (PCNs) are dioxins-like compounds and are formed along with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in thermal and combustion procedures. Chlorophenols (CPs) are the most important forerunners of PCNs. A comprehensive comprehension of PCN formation procedure from CPs is a precondition for reducing the discharge of PCNs. Experiments on the formation of PCNs from CPs have been hindered by PCN toxicity and short of precise detection methods for active intermediate radicals. In this work, PCN formation mechanism in gas-phase condition from 2-chlorophenol (2-CP) as forerunner was studied by quantum chemistry calculations. Numbers of energetically advantaged formation routes were proposed. The rate constants of key elementary steps were calculated over 600–1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT) method. This study illustrates formation of PCNs with one chlorine atom loss from 2-CP is preferred over that without chlorine atom loss. In comparison with formation of PCDFs from 2-CP, PCN products are less chlorinated and have lower formation potential.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.