Structural and catalytic properties of lanthanide (La, Eu, Gd) doped ceria

Journal Article · Tue Nov 15 00:00:00 EST 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.09.018· OSTI ID:21580070

Laguna, O H; Centeno, M A; Odriozola, J A ^[1]

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1. Instituto de Ciencia de Materiales de Sevilla, Centro Mixto Universidad de Sevilla-CSIC, Avda. Americo Vespucio 49, 41092 Seville (Spain)

Ce{sub 0.9}M{sub 0.1}O{sub 2-{delta}} mixed oxides (M=La, Eu and Gd) were synthesized by coprecipitation. Independent of the dopant cation, the obtained solids maintain the F-type crystalline structure, characteristic of CeO{sub 2} (fluorite structure) without phase segregation. The ceria lattice expands depending on the ionic radii of the dopant cation, as indicated by X-ray diffraction studies. This effect also agrees with the observed shift of the F{sub 2g} Raman vibrational mode. The presence of the dopant cations in the ceria lattice increases the concentration of structural oxygen vacancies and the reducibility of the redox pair Ce{sup 4+}/Ce{sup 3+}. All synthesized materials show higher catalytic activity for the CO oxidation reaction than that of bare CeO{sub 2}, being Eu-doped solid the one with the best catalytic performances despite of its lower surface area. - Graphical abstract: In this work, Ce{sub 0.9}M{sub 0.1}O{sub 2-{delta}} mixed oxides (M=La, Eu and Gd) were synthesized by coprecipitation. Independent of the dopant cation, the obtained solids maintain the F-type crystalline structure, characteristic of CeO{sub 2} (fluorite structure) without phase segregation. The ceria lattice expands depending on the ionic radii of the dopant cation, as indicated by X-ray diffraction studies. This effect also agrees with the observed shift of the F{sub 2g} Raman vibrational mode. The presence of the dopant cations in the ceria lattice increases the concentration of structural oxygen vacancies and the reducibility of the redox pair Ce{sup 4+}/Ce{sup 3+}. All synthesized materials show higher catalytic activity for the CO oxidation reaction than that of bare CeO{sub 2}, being Eu-doped solid the one with the best catalytic performances despite of its lower surface area. Highlights: > Lanthanide doped ceria as catalytic supports for CO oxidation reaction. > A higher concentration of oxygen vacancies promotes a higher catalytic activity. > Eu-doped ceria shows improved catalytic properties for the CO oxidation reaction.

• OSTI ID: 21580070
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 11; Other Information: DOI: 10.1016/j.jssc.2011.09.018; PII: S0022-4596(11)00509-3; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ATOMIC RADII
CARBON MONOXIDE
CATIONS
CERIUM IONS
CERIUM OXIDES
COPRECIPITATION
DOPED MATERIALS
FLUORITE
OXIDATION
OXYGEN
RARE EARTHS
SEGREGATION
SOLIDS
SURFACE AREA
VACANCIES
X-RAY DIFFRACTION
CARBON COMPOUNDS
CARBON OXIDES
CERIUM COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DIFFRACTION
ELEMENTS
HALIDE MINERALS
IONS
MATERIALS
METALS
MINERALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
POINT DEFECTS
PRECIPITATION
RARE EARTH COMPOUNDS
SCATTERING
SEPARATION PROCESSES
SURFACE PROPERTIES