Oxygen Storage/Redox Capacity and Related Phenomena on Ceria-Based Catalysts

Descorme, C.; Duprez, Daniel

doi:10.1142/9781860949654_0007

Cited by 32 publications

(18 citation statements)

References 67 publications

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“…A Ce/Pr mixed oxide was deposited over each alumina by incipient wetness impregnation with an aqueous solution of the lanthanide nitrates, being the final composition of the samples: 25% Ce 0. 8 dried and calcined in air at 500 • C. The calcination temperature was high enough to assure the complete removal of nitrates from the impregnation step, as revealed by wide scan photoelectron spectra taken from the calcined samples. OSC was measured by oxygen consumption at 200 • C in a Micromeritics ASAP-2020 volumetric adsorption device.…”

Section: Methodsmentioning

confidence: 99%

“…[4 -7] Generally, the redox behavior of ceria-based materials is evaluated by Oxygen Storage Capacity (OSC) measurements, and its loss is a major cause of deactivation. [8] In alumina-supported mixed oxides, redox deactivation can be attributed to the incorporation of reduced trivalent cations into the structure of alumina. [9,10] This produces the formation of an aluminate with perovskite-like structure.…”

Section: Introductionmentioning

confidence: 99%

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Origin of the redox deactivation phenomena in modified alumina‐supported Ce/Pr mixed oxide

Aboussaïd

Bernal

Blanco

et al. 2008

Surface & Interface Analysis

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However, at 900 • C, there is a decrease of OSC, which is moderate for silica-modified sample, while for lanthana-modified catalyst, the OSC is almost negligible. XPS analysis of the fresh samples shows that the redox state of cerium cations close to the surface is mainly +4, while praseodymium appears always as Pr 3+ . Samples reduced at different temperatures were also investigated by XPS. In the case of silica-modified alumina reduced at 900 • C, significant amounts of Ce 4+ can still be detected, which is in good agreement with the OSC value observed at that temperature. However, lanthana-modified sample reduced at 800 • C shows an important amount of Ce 3+ , being the only oxidation state observed for cerium after reduction at 900 • C. This is in good agreement with the strong drop in OSC observed for this latter sample, which can be thus attributable to the trapping of trivalent cations by the alumina, forming a stable perovskite-like aluminate, LnAlO 3 , as confirmed by X-Ray Diffraction (XRD).

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Origin of the redox deactivation phenomena in modified alumina‐supported Ce/Pr mixed oxide

Aboussaïd

Bernal

Blanco

et al. 2008

Surface & Interface Analysis

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“…Cerium(IV) is a strong one-electron oxidant and its use in areas such as organic synthesis [1][2][3], bioinorganic chemistry [4,5], materials science [6] and industrial catalysts such as automotive catalytic converters [7][8][9][10][11][12][13] is widespread. Soluble cerium(IV) complexes are also important precursors for the preparation of ceria nanoparticles [14] and this has increased the demand for well-characterized precursors for the development of this area.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Cerium(IV) Metallocenes

et al. 2015

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“…OSC measurements are currently carried out by the dynamic technique, in which CO or H 2 pulses are injected over the preoxidized sample at regular time intervals. [32,33] As mentioned above, it is generally accepted that one surface oxygen atom out of four is involved in the redox process shown in Equation (2), which represents a theoretical OSC value of 5.4 mmol O m À2 for a mean surface density of 13.1 mmol O m À2 . [22,33] Reduced ceria is able to dissociate water [34][35][36][37][38] or carbon dioxide [34,36] according to Equation (4) or the reverse of Equation (2) Ceria also possesses versatile acid-base properties, depending on the nature and temperature of the pretreatment.…”

Section: Introductionmentioning

confidence: 99%

Ceria‐Based Solid Catalysts for Organic Chemistry

Vivier¹,

Duprez²

2010

ChemSusChem

Self Cite

357

244

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Ceria has been the subject of thorough investigations, mainly because of its use as an active component of catalytic converters for the treatment of exhaust gases. However, ceria‐based catalysts have also been developed for different applications in organic chemistry. The redox and acid–base properties of ceria, either alone or in the presence of transition metals, are important parameters that allow to activate complex organic molecules and to selectively orient their transformation. Pure ceria is used in several organic reactions, such as the dehydration of alcohols, the alkylation of aromatic compounds, ketone formation, and aldolization, and in redox reactions. Ceria‐supported metal catalysts allow the hydrogenation of many unsaturated compounds. They can also be used for coupling or ring‐opening reactions. Cerium atoms can be added as dopants to catalytic system or impregnated onto zeolites and mesoporous catalyst materials to improve their performances. This Review demonstrates that the exceptional surface (and sometimes bulk) properties of ceria make cerium‐based catalysts very effective for a broad range of organic reactions.

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Oxygen Storage/Redox Capacity and Related Phenomena on Ceria-Based Catalysts

Cited by 32 publications

References 67 publications

Origin of the redox deactivation phenomena in modified alumina‐supported Ce/Pr mixed oxide

Origin of the redox deactivation phenomena in modified alumina‐supported Ce/Pr mixed oxide

Synthesis and Characterization of Cerium(IV) Metallocenes

Ceria‐Based Solid Catalysts for Organic Chemistry

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