The role of low coverage sodium surface species on electrochemical promotion in a Pt/YSZ system

Naimah Ibrahim, Mas Rahayu Jalil, Danai Poulidi, Ian S. Metcalfe*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The effect of sodium-modification on the catalyst and electrocatalytic properties of a platinum catalyst supported on a YSZ solid electrolyte was studied. Increasing the sodium coverage on the catalyst surface appears to block some of the three-phase boundary (tpb) sites and reduces the rate of the charge transfer reaction. The promotion of the platinum surface reaction (ethylene oxidation) seems to a first approximation to be a function of the rate of oxygen supply or removal to or from the surface irrespective of whether this is contaminated by sodium or not (samples with sodium contamination require a higher overpotential to achieve the same current density as a clean sample because of poisoning in the tpb). At high negative polarisations (oxygen removed from the surface) the sodium contaminated samples show a significant increase in rate, possibly due to the decomposition of e.g. sodium hydroxides and carbonates.

Original languageEnglish
Pages (from-to)386-389
Number of pages4
JournalSolid State Ionics
Volume225
DOIs
Publication statusPublished - 04 Oct 2012

Keywords

  • Cyclic voltammetry
  • EPOC
  • Ethylene oxidation
  • Na species
  • Oxygen charge transfer
  • Pt
  • YSZ

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Chemistry(all)

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