Degradation of selected perfluoroalkyl substances (PFASs) using AlF3 in water

Abstract

The conversion of representative perfluorinated carboxylic acids and perfluorinated sulfonic acids in aqueous solutions into the corresponding perfluoroalkenes is investigated by using electronic structure methods. It is demonstrated that the use of aluminum trifluoride enables such conversions even at room temperature (with the reaction completion time not exceeding 1 minute). The mechanism of the reactions studied involves the withdrawal of F⁻ from either the carboxylic or the sulfonic anion by AlF₃ which leads to the formation of a stable AlF₄⁻ anion and a perfluoroalkene compound (which can be further decomposed to a series of nonfluorinated products) accompanied by CO₂ or SO₃ loss.