全氟戊酸降解机理的理论研究

Theoretical Study on Decomposition Mechanism of Perfluoropentanoic Acid

对全氟戊酸(PFPeA)的热降解机理进行理论研究,在CCSD(T)/6-31+G(d,p)//B3LYP/6-31+G(d,p)水平计算得到PFPeA分子4条热降解反应通道及势能面.结果表明,PFPeA→HF+CO+CF3CF2CF2CFO反应通道最具反应优势,需要翻越的反应势垒最低,为151.9kJ/mol.

Perfluorinated carboxylic acids as a kind of persistent organic pollutants have been caused widespread concern because of its widely exists in various environmental media. The thermal degradation mechanism of PFPeA was studied,so as to provide a theoretical basis for experimental degradation meth-od. Four thermal degradation pathways and a potential energy surface were theoretically predicted at the CCSD （T） / 6 - 31 ＋ G （ d, p） //B3 LYP/6 - 31 ＋ G （ d, p） level. The result s show that the lowest energy reac-tion pathway in the four thermal degradation pathways is the molecular elimination of HF to form CF3CF2CF2CFO radical,which the potential barrier energy is 151.9 kJ/mol.