Dry reforming of methane over nickel supported on Nd-ceria: enhancement of the catalytic properties and coke resistance
Por:
Lara-Garcia, Hugo A., Araiza, Daniel G., Mendez-Galvan, Melissa, Tehuacanero-Cuapa, Samuel, Gomez-Cortes, Antonio, Diaz, Gabriela
Publicada:
10 sep 2020
Resumen:
Nickel (5 wt%) supported on Nd-doped ceria was studied as catalysts in
the DRM reaction at stoichiometric conditions in the range of 600-800
degrees C. Ce(1-x)Nd(x)O(2-delta)supports with different Nd contents (x=
0, 0.05, 0.1 and 0.2) were successfully synthesized. The role of oxygen
vacancies by the incorporation of Nd(3+)into the ceria lattice was
investigated. These species were quantified by XRD and Raman
spectroscopy, showing a linear dependence as a function of Nd content.
Ni/Nd-ceria catalysts were prepared by wet impregnation. Although
formation of oxygen vacancies, as well as microstructural features of
the support (smaller crystallite sizes, higher surface area, and
developed mesoporous structure) were improved as a function of the Nd
content, no significant differences were observed in the catalytic
properties of Ni/Nd-ceria in the DRM reaction. Despite this, compared to
undoped ceria, all the Nd-doped CeO(2)catalysts present an enhanced
activity and stability, and the best catalytic performance was observed
in the Ni/Ce(0.95)Nd(0.05)O(2-delta)sample. Quantification of carbon
residues in spent catalysts showed, as expected, lower amounts in the
Ni/Nd-ceria samples; nevertheless, among them, the catalyst with the
higher amount of oxygen vacancies, is the one with the higher carbon
residues. Incorporation of Nd in ceria changes the acid/base properties,
diminishing the gasification capacity of the carbonaceous species. These
results emphasize that the activity and stability in the Ni/Nd-ceria
catalysts for the DRM reaction depend on two key factors, the redox and
the acid/base properties of the CeO(2)supports, offering insights about
the necessary and adequate balance between these properties.
Filiaciones:
Lara-Garcia, Hugo A.:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico
Araiza, Daniel G.:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico
Mendez-Galvan, Melissa:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico
Tehuacanero-Cuapa, Samuel:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico
Gomez-Cortes, Antonio:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico
Diaz, Gabriela:
Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico
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