Stable surface oxygen on nanostructured silver for efficient CO2 electroreduction

Michael Shincheon Jee, Haeri Kim, Hyo Sang Jeon, Keun Hwa Chae, Jinhan Cho, Byoung Koun Min, Yun Jeong Hwang

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We investigated properties involved in the enhancement in electrocatalytic carbon dioxide (CO2) reduction to carbon monoxide (CO) in electrochemically treated Ag surfaces with surface sensitive analysis methods such as Auger spectroscopy, atomic force microscopy (AFM) coupled with Kelvin probe force microscopy (KPFM) techniques, and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The absence of Ag M4,5VV Auger signals for the electrochemically treated Ag indicate the presence of localized surface oxygen (O) which survives on the best performing Ag electrocatalysts even in the reductive environment of the CO2 reduction reaction. Higher work functions were located at the nanostructure boundaries observed by KPFM/AFM implying the higher surface O concentrations in these regions. Furthermore, NEXAFS measured the selective prominence of π* states over σ* in the active Ag surfaces which suggests stronger interaction with intermediates of CO2 reduction while minimizing the -OH interaction contributing to increase CO2 reduction activity and selectivity. These results provide direction in engineering surfaces for efficient electrochemical CO2 conversion.

Original languageEnglish
JournalCatalysis Today
DOIs
Publication statusAccepted/In press - 2016 Jul 18

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Keywords

  • Auger spectroscopy
  • CO electroreduction
  • KPFM
  • NEXAFS
  • Silver
  • Surface oxygen

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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