Investigating electrode flooding in a flowing electrolyte, gas‐fed carbon dioxide electrolyzer

McLain E. Leonard, Lauren E. Clarke, Antoni Forner-Cuenca, Steven M. Brown, Fikile R. Brushett (Corresponding author)

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)
1 Downloads (Pure)

Abstract

Managing the gas–liquid interface within gas-diffusion electrodes (GDEs) is key to maintaining high product selectivities in carbon dioxide electroreduction. By screening silver-catalyzed GDEs over a range of applied current densities, an inverse correlation was observed between carbon monoxide selectivity and the electrochemical double-layer capacitance, a proxy for wetted electrode area. Plotting current-dependent performance as a function of cumulative charge led to data collapse onto a single sigmoidal curve indicating that the passage of faradaic current accelerates flooding. It was hypothesized that high cathode alkalinity, driven by both initial electrolyte conditions and cathode half-reactions, promotes carbonate formation and precipitation which, in turn, facilitates electrolyte permeation. This mechanism was reinforced by the observations that post-test GDEs retain less hydrophobicity than pristine materials and that water-rinsing and drying electrodes temporarily recovers peak selectivity. This knowledge offers an opportunity to design electrodes with greater carbonation tolerance to improve device longevity.

Original languageEnglish
Pages (from-to)400-411
Number of pages12
JournalChemSusChem
Volume13
Issue number2
Early online date17 Nov 2019
DOIs
Publication statusPublished - 19 Jan 2020

    Fingerprint

Keywords

  • carbon dioxide reduction
  • electrochemistry
  • energy conversion
  • gas diffusion electrodes
  • wetting

Cite this