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Deactivation study of Fe2O3−CeO2 during redox cycles for CO production from CO2

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Abstract
Deactivation was investigated in Fe2O3-CeO2 oxygen storage materials during repeated H-2-reduction and CO2-reoxidation. In situ XRD, XAS, and TEM were used to identify phases, crystallite sizes, and morphological changes upon cycling operation. The effect of redox cycling was investigated both in Fe-rich (80 wt % Fe2O3-CeO2) and Ce-rich (10 wt %Fe2O3-CeO2) materials. The former consisted of 100 nm Fe2O3 particles decorated with 5-10 nm Ce1-xFexO2-x. The latter presented CeO2 with incorporated Fe, i.e. a solid solution of Ce1-xFexO2-x, as the main oxygen carrier. By modeling the EXAFS Ce-K signal for as-prepared 10 wt %Fe2O3-CeO2, the amount of Fe in CeO2 was determined as 21 mol %, corresponding to 86% of the total iron content. Sintering and solid solid transformations, the latter including both new phase formation and element segregation, were identified as deactivation pathways upon redox cycling. In Ce-rich material, perovskite (CeFeO3) was identified by XRD. This phase remained inert during reduction and reoxidation, resulting in an overall lower oxygen storage capacity. Further, Fe segregated from the solid solution, thereby decreasing its reducibility. In addition, an increase in crystallite size occurred for all phases. In Fe-rich material, sintering is the main deactivation pathway, although Fe segregation from the solid solution and perovskite formation cannot be excluded.
Keywords
OXYGEN STORAGE MATERIAL, CHEMICAL-LOOPING COMBUSTION, IRON-OXIDE MATERIALS, X-RAY-DIFFRACTION, GAS SHIFT PROCESS, HYDROGEN-PRODUCTION, CARRIER, METHANE, REDUCTION, FE

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Chicago
Dharanipragada, Naga Venkata Ranga Aditya, Maria Meledina, Vladimir Galvita, Hilde Poelman, Stuart Turner, Gustaaf Van Tendeloo, Christophe Detavernier, and Guy Marin. 2016. “Deactivation Study of Fe2O3−CeO2 During Redox Cycles for CO Production from CO2.” Industrial & Engineering Chemistry Research 55 (20): 5911–5922.
APA
Dharanipragada, N. V. R. A., Meledina, M., Galvita, V., Poelman, H., Turner, S., Van Tendeloo, G., Detavernier, C., et al. (2016). Deactivation study of Fe2O3−CeO2 during redox cycles for CO production from CO2. INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 55(20), 5911–5922.
Vancouver
1.
Dharanipragada NVRA, Meledina M, Galvita V, Poelman H, Turner S, Van Tendeloo G, et al. Deactivation study of Fe2O3−CeO2 during redox cycles for CO production from CO2. INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH. 2016;55(20):5911–22.
MLA
Dharanipragada, Naga Venkata Ranga Aditya, Maria Meledina, Vladimir Galvita, et al. “Deactivation Study of Fe2O3−CeO2 During Redox Cycles for CO Production from CO2.” INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 55.20 (2016): 5911–5922. Print.
@article{8055035,
  abstract     = {Deactivation was investigated in Fe2O3-CeO2 oxygen storage materials during repeated H-2-reduction and CO2-reoxidation. In situ XRD, XAS, and TEM were used to identify phases, crystallite sizes, and morphological changes upon cycling operation. The effect of redox cycling was investigated both in Fe-rich (80 wt \% Fe2O3-CeO2) and Ce-rich (10 wt \%Fe2O3-CeO2) materials. The former consisted of 100 nm Fe2O3 particles decorated with 5-10 nm Ce1-xFexO2-x. The latter presented CeO2 with incorporated Fe, i.e. a solid solution of Ce1-xFexO2-x, as the main oxygen carrier. By modeling the EXAFS Ce-K signal for as-prepared 10 wt \%Fe2O3-CeO2, the amount of Fe in CeO2 was determined as 21 mol \%, corresponding to 86\% of the total iron content. Sintering and solid solid transformations, the latter including both new phase formation and element segregation, were identified as deactivation pathways upon redox cycling. In Ce-rich material, perovskite (CeFeO3) was identified by XRD. This phase remained inert during reduction and reoxidation, resulting in an overall lower oxygen storage capacity. Further, Fe segregated from the solid solution, thereby decreasing its reducibility. In addition, an increase in crystallite size occurred for all phases. In Fe-rich material, sintering is the main deactivation pathway, although Fe segregation from the solid solution and perovskite formation cannot be excluded.},
  author       = {Dharanipragada, Naga Venkata Ranga Aditya and Meledina, Maria and Galvita, Vladimir and Poelman, Hilde and Turner, Stuart and Van Tendeloo, Gustaaf and Detavernier, Christophe and Marin, Guy},
  issn         = {0888-5885},
  journal      = {INDUSTRIAL \& ENGINEERING CHEMISTRY RESEARCH},
  keyword      = {OXYGEN STORAGE MATERIAL,CHEMICAL-LOOPING COMBUSTION,IRON-OXIDE MATERIALS,X-RAY-DIFFRACTION,GAS SHIFT PROCESS,HYDROGEN-PRODUCTION,CARRIER,METHANE,REDUCTION,FE},
  language     = {eng},
  number       = {20},
  pages        = {5911--5922},
  title        = {Deactivation study of Fe2O3\ensuremath{-}CeO2 during redox cycles for CO production from CO2},
  url          = {http://dx.doi.org/10.1021/acs.iecr.6b00963},
  volume       = {55},
  year         = {2016},
}

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