Unraveling the Mechanism of Water-Mediated Sulfur Tolerance via Operando Surface-Enhanced Raman Spectroscopy

Jun Hyuk Kim, Zhao Ying Chern, Seonyoung Yoo, Ben Deglee, Jenghan Wang, Meilin Liu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


While several proton-conducting anode materials have shown excellent tolerance to sulfur poisoning, the mechanism is still unclear due largely to the inability to probe miniscule amounts of sulfur-containing species using conventional surface characterization techniques. Here we present our findings in unraveling the mechanism of water-mediated sulfur tolerance of a proton conductor under operating conditions empowered by surface-sensitive, operando surface-enhanced Raman spectroscopy (SERS) coupled with impedance spectroscopy. Contrary to the conventional view that surface-adsorbed sulfur is removed mainly by oxygen anions, it is found that -SO4 groups on the surface of the proton conductor are converted to SO2 by a water-mediated process, as confirmed by operando SERS analysis and density functional theory (DFT)-based calculations. The combination of operando SERS performed on a model electrode and theoretical computation offers an effective approach to investigate into complex mechanisms of electrode processes in various electrochemical systems, providing information vital to achieve the rational design of better electrode materials.

Original languageEnglish
Pages (from-to)2370-2379
Number of pages10
JournalACS Applied Materials and Interfaces
Issue number2
Publication statusPublished - 2020 Jan 15


  • Raman spectroscopy
  • anode
  • fuel cell
  • solid oxide fuel cell
  • sulfur poisoning

ASJC Scopus subject areas

  • General Materials Science


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