| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 47054 | Applied Catalysis B: Environmental | 2011 | 7 Pages |
The physical properties of the Ba-loaded Ce–Fe mixed oxide catalysts, which exhibited high activity for NO decomposition to N2, were investigated. The optimum Fe/(Ce + Fe) molar ratio was 0.02. The X-ray absorption near edge structure, electron spin resonance, and diffuse reflectance UV–vis spectra indicated that the optimum catalyst had the highest proportion of isolated tetrahedral Fe3+ ions in all the Fe species. Raman spectra suggested that incorporation of Fe3+ in the fluorite structure of CeO2 caused an increase in the concentration of oxygen vacancies, which play an important role in the NO decomposition activity of the catalysts. Temperature-programmed desorption (TPD) of O2 showed that the addition of the Fe component to BaO/CeO2 enhanced O2 uptakes and facilitated oxygen desorption. NO-TPD profiles showed that NO desorption was associated with the desorption of O2, indicating that these two species are formed by decomposition of surface nitrate species.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► CeO2–Fe2O3 solid solutions with the CeO2 cubic fluorite structure are formed. ► Local structure of iron had a tetrahedral coordination environment. ► Incorporation of Fe3+ in fluorite structure causes the formation of oxygen vacancies. ► Oxygen vacancies play important roles in the NO decomposition activity.
