In situ FTIR spectroscopy of highly dispersed FeOx catalysts for NO reduction: Role of Na promoter

Charles A. Roberts, Louisa Savereide, David J. Childers, Torin C. Peck, Justin M. Notestein

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The effect of Na on highly dispersed FeOx impregnated onto CeO2 via the unique precursor Na/Fe-ethylenediaminetetraacetate (NaFeEDTA) was investigated by comparison to a series of well-defined catalysts synthesized by the traditional precursor Fe(NO3)3 both with and without Na addition. Catalysts were evaluated for steady-state NO reduction by CO and activities varied based on synthesis method and Fe:Na ratio. Na contributed a promoter effect when added at a stoichiometric ratio (Fe:Na = 1), providing an explanation for the higher activity of NaFeEDTA/CeO2 for NO reduction by CO. Activity decreased when excess Na was present in Fe(NO3)3 catalysts, but the stoichiometric promoter effect persisted up to ∼4.0 Fe/nm2. In situ Fourier transform infrared (FTIR) spectroscopy during NO adsorption revealed the presence of unique NO adsorption species (1460 cm-1) on the NaFeEDTA/CeO2, suggesting enhanced NO adsorption due to Na. At reaction temperature, FTIR bands of bulk nitrates on CeO2 were quantitatively shown to more rapidly undergo NO reduction catalytic transformations over NaFeEDTA/CeO2. These results increase understanding of mechanistic effects of Na on NO reduction over FeOx/CeO2 catalysts and serve to guide future design of oxide-based emission control catalysts that are free of Pt-group metals.

Original languageEnglish
Pages (from-to)56-64
Number of pages9
JournalCatalysis Today
Volume267
DOIs
Publication statusPublished - Jun 1 2016

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Keywords

  • Carbon monoxide
  • FTIR
  • In situ
  • Iron oxide
  • Nitric oxide
  • Sodium promoter

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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