Chemical and Nanostructural Aspects of the Preparation and Characterisation of Ceria and Ceria-Based Mixed Oxide-Supported Metal Catalysts

Bernal, S.; Calvino, José J.; Gatica, José M.; López-Cartés, C.; Pintado, José

doi:10.1142/9781860949654_0004

Cited by 37 publications

(25 citation statements)

References 200 publications

(600 reference statements)

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“…The interpretation of the CO uptake data is difficult because ceria is known to adsorb large amounts of CO 11 and noble metals can adsorb more than one CO atom per noble metal, a phenomenon dependent on the exposed crystal faces in the catalyst. 12 The purpose of this study was to evaluate the possibility of using CO chemisorption as a qualitative activityscreening tool for the WGS reaction.…”

Section: Resultsmentioning

confidence: 99%

Water gas shift activity of noble metals supported on ceria‐zirconia oxides

Radhakrishnan¹,

Willigan²,

Dardas³

et al. 2006

AIChE Journal

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Section: Resultsmentioning

confidence: 99%

Water gas shift activity of noble metals supported on ceria‐zirconia oxides

Radhakrishnan¹,

Willigan²,

Dardas³

et al. 2006

AIChE Journal

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“…11, curve 3). In general, promoting effect of supported Pt group metals on the oxides reduction by hydrogen is a well-documented phenomenon explained by the efficient activation of H 2 molecules on the metal particles and spill-over of atomic hydrogen onto the oxide surface, thus easily removing reactive oxygen forms (Bernal et al, 2002). Downward shift of H 2 TPR peak is observed for any mechanism of the solid oxide reduction, either topochemical (such as NiO reduction) or diffusion-controlled (reduction of ceria-zirconia solid oxide solution).…”

Section: H 2 Tprmentioning

confidence: 99%

Nanocomposite Catalysts for Steam Reforming of Methane and Biofuels: Design and Performance

Садыков¹,

Mezentseva²,

Alikina³

et al. 2011

Advances in Nanocomposites - Synthesis, Characterization and Industrial Applications

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“…This alumina was used as support to prepare a 25% wt supported Ce 1−x Pr x O 2−y mixed oxide by co-impregnation with an aqueous solution of Ce and Pr nitrates from Rhodia, using incipient wetness impregnation technique. [3,6] Deposition of the Ce/Pr mixed phase was done in one impregnation cycle. The sample was dried overnight at 120 • C, and finally calcined in air at 500 • C for 6 h. The final Rh catalyst was prepared by impregnation of the alumina-supported cerium-praseodymium mixed oxide with an aqueous solution of Rh(NO 3 ) 3 (pH = 2) provided by Alfa Aesar.…”

Section: Methodsmentioning

confidence: 99%

“…[2 -5] Typically, incipient wetness impregnation has been used to incorporate the noble metal to the Ce/Pr mixed oxide. [3,6] In this method, the support is put in contact with an aqueous solution of a salt of the noble metal. As the oxidation state of the noble metal is usually high (+3 for rhodium), the solutions used for impregnation are strongly acidic.…”

Section: Introductionmentioning

confidence: 99%

Actual constitution of the mixed oxide promoter in a Rh/Ce_1−xPr_xO_2−y/Al₂O₃ catalyst. Evolution throughout the preparation steps

Aboussaïd¹,

Bernal²,

Blanco³

et al. 2008

Surface & Interface Analysis

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The evolution of the ceria-praseodymia mixed oxide promoter throughout the successive steps involved in the preparation of a 3% Rh/25% Ce 0.8 Pr 0.2 O 2−x /Al 2 O 3 -3.5% SiO 2 catalyst is studied with the help of X-ray diffraction (XRD), spatially resolved electron energy loss spectroscopy (EELS), XPS, and thermal programed desorption (TPD) techniques. Incipient wetness impregnation has been used to obtain the appropriate loading of this promoter. As revealed by XRD, EELS, and XPS data, the alumina-supported CeO 2 -PrO 2−x mixed oxide sample consisted of a bimodal distribution of the particles of the promoter. XRD shows two fluorite-like phases: cerium-rich particles with a mean crystallite size greater than 6 nm and smaller praseodymium-rich crystals, about 3.5 nm size. Surface Ce/Pr ratio obtained by XPS was consistent with a higher dispersion of the praseodymium-rich oxide particles. The final Rh catalyst was prepared in a second step, by impregnation of the CePrO x /Al 2 O 3 system with an acidic solution of Rh(NO 3 ) 3 . The low pH of this solution is responsible for further modifications of the lanthanide oxides distribution. Thus, there is a redispersion of the praseodymium-rich phase, which is evidenced by EELS and XPS data. Likewise, CO 2 desorption from samples exposed to the atmosphere is consistent with an enhanced basicity of the sample due to the increase of Pr 3+ content at the surface of the catalyst. The observed changes on the nanostructure of the mixed oxide promoter can be attributable to a partial dissolution of the oxide, selectively leaching Pr 3+ cations from the lattice, which are finally deposited as small particles after the drying steps of the preparation.

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Chemical and Nanostructural Aspects of the Preparation and Characterisation of Ceria and Ceria-Based Mixed Oxide-Supported Metal Catalysts

Cited by 37 publications

References 200 publications

Water gas shift activity of noble metals supported on ceria‐zirconia oxides

Water gas shift activity of noble metals supported on ceria‐zirconia oxides

Nanocomposite Catalysts for Steam Reforming of Methane and Biofuels: Design and Performance

Actual constitution of the mixed oxide promoter in a Rh/Ce_1−xPr_xO_2−y/Al₂O₃ catalyst. Evolution throughout the preparation steps

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Chemical and Nanostructural Aspects of the Preparation and Characterisation of Ceria and Ceria-Based Mixed Oxide-Supported Metal Catalysts

Cited by 37 publications

References 200 publications

Water gas shift activity of noble metals supported on ceria‐zirconia oxides

Water gas shift activity of noble metals supported on ceria‐zirconia oxides

Nanocomposite Catalysts for Steam Reforming of Methane and Biofuels: Design and Performance

Actual constitution of the mixed oxide promoter in a Rh/Ce1−xPrxO2−y/Al2O3 catalyst. Evolution throughout the preparation steps

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Product

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Actual constitution of the mixed oxide promoter in a Rh/Ce_1−xPr_xO_2−y/Al₂O₃ catalyst. Evolution throughout the preparation steps