Direct measurement of fluorocarbon radicals in the thermal destruction of perfluorohexanoic acid using photoionization mass spectrometry
Year: 2025
Type: article
Abstract: Thermal destruction is a critical cornerstone of addressing the rampant contamination of natural resources with per- and polyfluoroalkyl substances (PFAS). However, grave concerns associated with stack emissions from incineration exist because mechanistic studies have thus far relied on ex situ analyses of end products and theoretical calculations. Here, we used synchrotron-based vacuum ultraviolet photoionization mass spectrometry to study the pyrolysis of a representative PFAS—perfluorohexanoic acid—and provide direct evidence of fluorocarbon radicals and intermediates. A key reaction pathway from perfluorocarboxylic acids to ketenes via acyl fluorides is proposed. We furthermore propose CF 2 /CF 3 radical–centered pyrolysis mechanisms and explain their roles in the formation of other products that may form in full-scale incinerators. These results have not only unveiled the role of radicals and intermediates in thermal PFAS decomposition and recombination mechanisms but also provide unique insight into improving the safety and viability of industrial PFAS incineration.
Source: Science Advances
Institutions: University of Science and Technology of China, National Synchrotron Radiation Laboratory, Colorado State University, University of Newcastle Australia, Environmental Protection Agency, Oak Ridge Institute for Science and Education, Veolia (Australia), Monash University, Lawrence Berkeley National Laboratory, Commonwealth Scientific and Industrial Research Organisation, CSIRO Environment
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,500
OpenAlex ID: W4408030099