Title
An expanded reaction kinetic model of the CuO surface-mediated formation of PCDD/F from pyrolysis of 2-chlorophenol
Document Type
Article
Publication Date
8-1-2007
Abstract
An expanded reaction kinetic model, including 17 surface reactions, is proposed to explain the yields of PCDD/F obtained in an experimental study of the reaction of 2-chlorophenol over a CuO/silica surface. The mechanism is loosely based on the gas-phase mechanism for PCDD/F formation widely discussed in the literature. The principal differences are the impact of chemisorption of 2-chlorophenols to metal oxides on radical formation and the steric hindrance of oxygen-centered radicals on the surface inhibiting radical-radical reaction pathways that lead to formation of dibenzo-p-dioxin (DD). Gas-phase molecule-surface-bound adsorbate reactions are the preferred route of DD formation, while radical-radical surface reactions are the main channel for dichloro-dibenzofuran (DCDF) formation. These results suggest that the Langmuir-Hinshelwood (LH) mechanism, involving radical-radical surface reactions, and the Eley-Rideal mechanism, involving a gas-phase molecule and surface-bound adsorbate, are responsible for PCDF and PCDD formation on surfaces, respectively. The calculated yields of DCDF and DD are in reasonable agreement with experimental results.
Publication Source (Journal or Book title)
Chemosphere
First Page
1741
Last Page
50
Recommended Citation
Khachatryan, L., Lomnicki, S., & Dellinger, B. (2007). An expanded reaction kinetic model of the CuO surface-mediated formation of PCDD/F from pyrolysis of 2-chlorophenol. Chemosphere, 68 (9), 1741-50. https://doi.org/10.1016/j.chemosphere.2007.03.042