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Degradation of Perfluorooctanoic Acid on Aluminum Oxide Surfaces: New Mechanisms from Ab Initio Molecular Dynamics Simulations.
Biswas, Sohag; Wong, Bryan M.
Afiliación
  • Biswas S; Materials Science & Engineering Program, Department of Chemistry, and Department of Physics & Astronomy, University of California─Riverside, Riverside, California 92521, United States.
  • Wong BM; Materials Science & Engineering Program, Department of Chemistry, and Department of Physics & Astronomy, University of California─Riverside, Riverside, California 92521, United States.
Environ Sci Technol ; 57(16): 6695-6702, 2023 04 25.
Article en En | MEDLINE | ID: mdl-37018510
Perfluorooctanoic acid (PFOA) is a part of a large group of anthropogenic, persistent, and bioaccumulative contaminants known as per- and polyfluoroalkyl substances (PFAS) that can be harmful to human health. In this work, we present the first ab initio molecular dynamics (AIMD) study of temperature-dependent degradation dynamics of PFOA on (100) and (110) surfaces of γ-Al2O3. Our results show that PFOA degradation does not occur on the pristine (100) surface, even when carried out at high temperatures. However, introducing an oxygen vacancy on the (100) surface facilitates an ultrafast (<100 fs) defluorination of C-F bonds in PFOA. We also examined degradation dynamics on the (110) surface and found that PFOA interacts strongly with Al(III) centers on the surface of γ-Al2O3, resulting in a stepwise breaking of C-F, C-C, and C-COO bonds. Most importantly, at the end of the degradation process, strong Al-F bonds are formed on the mineralized γ-Al2O3 surface, which prevents further dissociation of fluorine into the surrounding environment. Taken together, our AIMD simulations provide critical reaction mechanisms at a quantum level of detail and highlight the importance of temperature effects, defects, and surface facets for PFOA degradation on reactive surfaces, which have not been systematically explored or analyzed.
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Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Simulación de Dinámica Molecular / Fluorocarburos Límite: Humans Idioma: En Revista: Environ Sci Technol Año: 2023 Tipo del documento: Article País de afiliación: Estados Unidos

Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Simulación de Dinámica Molecular / Fluorocarburos Límite: Humans Idioma: En Revista: Environ Sci Technol Año: 2023 Tipo del documento: Article País de afiliación: Estados Unidos