Surface-Morphology-Dependent Electrolyte Effects on Gold-Catalyzed Electrochemical CO2 Reduction

Haeri Kim, Hyun Seo Park, Yun Jeong Hwang, Byoung Koun Min

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The electrocatalytic property of a flat or an oxide-derived nanostructure Au electrode was investigated using surface sensitive analysis methods such as impedance spectroscopy and Kelvin probe force microscopy (KPFM) when electrochemical conversion of carbon dioxide (CO2) to carbon monoxide (CO) was performed with either KHCO3- or NaHCO3-based neutral electrolyte. A strong dependence on the cation of the electrolyte was exhibited on the flat Au electrode surface. CO selectivity and capacitance dispersion are significantly higher with the KHCO3 electrolyte. On the other hand, the nanostructured Au electrodes, having much more improved activity and durability of CO2 reduction, showed much less electrolyte-dependent catalytic activity. The difference in CO selectivity with KHCO3 and NaHCO3 electrolytes can be explained by the difference in hydration level and consequent adsorption strength of the cations on the flat Au metal electrodes, implying that ion-pairing interactions between the metal, cations, CO2, and its intermediate play an important role in the reduction reaction. The local electric field fluctuation caused by the nanostructured rough Au surface can affect the electric double layer near the electrode surface and suppress the electrolyte-dependency of the reduction. Furthermore, according to X-ray spectroscopy analysis of the electrode after electrolysis, the nanostructured Au electrode is less prone to surface cation deposition. These results provide a basic understanding of the role of electrolyte cations in the CO2 reduction reaction.

Original languageEnglish
Pages (from-to)22637-22643
Number of pages7
JournalJournal of Physical Chemistry C
Volume121
Issue number41
DOIs
Publication statusPublished - 2017 Oct 19

Fingerprint

Gold
Electrolytes
Surface morphology
electrolytes
gold
Cations
Electrodes
electrodes
Positive ions
cations
Carbon Monoxide
Carbon monoxide
carbon monoxide
selectivity
Metals
Catalyst selectivity
electrolysis
X ray spectroscopy
durability
Electrolysis

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Cite this

Surface-Morphology-Dependent Electrolyte Effects on Gold-Catalyzed Electrochemical CO2 Reduction. / Kim, Haeri; Park, Hyun Seo; Hwang, Yun Jeong; Min, Byoung Koun.

In: Journal of Physical Chemistry C, Vol. 121, No. 41, 19.10.2017, p. 22637-22643.

Research output: Contribution to journalArticle

Kim, Haeri ; Park, Hyun Seo ; Hwang, Yun Jeong ; Min, Byoung Koun. / Surface-Morphology-Dependent Electrolyte Effects on Gold-Catalyzed Electrochemical CO2 Reduction. In: Journal of Physical Chemistry C. 2017 ; Vol. 121, No. 41. pp. 22637-22643.
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