Experimental insights into anodic oxidation of hexafluoropropylene oxide dimer acid (GenX) on boron-doped diamond anodes

Diwakar Suresh Babu, Johannes M.C. Mol, Josephus G. Buijnsters*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

12 Downloads (Pure)

Abstract

GenX is the trade name of the ammonium salt of hexafluoropropylene oxide dimer acid (HFPO-DA) and is used as a replacement for the banned perfluorooctanoic acid (PFOA). However, recent studies have found GenX to be more toxic than PFOA. This work deals with the electrochemical degradation of HFPO-DA using boron-doped diamond anodes. For the first time, an experimental study was conducted to investigate the influence of sulfate concentration and other operating parameters on HFPO-DA degradation. Results demonstrated that sulfate radicals were ineffective in HFPO-DA degradation due to steric hindrance by –CF3 branch. Direct electron transfer was found as the rate-determining step. By comparing degradation of HFPO-DA with that of PFOA, it was observed that the steric hindrance by –CF3 branch in HFPO-DA decreased the rate of electron transfer from the carboxyl head group even though its defluorination rate was faster. Conclusively, a degradation pathway is proposed in which HFPO-DA mineralizes to CO2 and Fˉ via formation of three intermediates.

Original languageEnglish
Article number132417
Number of pages10
JournalChemosphere
Volume288
DOIs
Publication statusPublished - 2022

Keywords

  • Boron-doped diamond (BDD)
  • Electrochemical oxidation
  • GenX
  • Hexafluoropropylene oxide dimer acid (HFPO-DA)
  • Hydroxyl radicals
  • Perfluorooctanoic acid (PFOA)

Fingerprint

Dive into the research topics of 'Experimental insights into anodic oxidation of hexafluoropropylene oxide dimer acid (GenX) on boron-doped diamond anodes'. Together they form a unique fingerprint.

Cite this