Journal ArticleDOI
New Pd/CexZr1−xO2/Al2O3 three-way catalysts prepared by microemulsion: Part 1. Characterization and catalytic behavior for CO oxidation
Marcos Fernández-García,Arturo Martínez-Arias,Ana Iglesias-Juez,Ana B. Hungría,James A. Anderson,José C. Conesa,J. Soria +6 more
TLDR
In this article, a series of palladium catalysts supported on ceria and ceria-zirconia/alumina in the calcined state and under a reactive CO+O2 atmosphere has been characterized by a combination of electron transmission microscopy, infrared and electron paramagnetic resonance spectroscopies, and the results obtained used to interpret the catalytic behavior displayed by the samples in the CO oxidation reaction.Abstract:
The state of a series of palladium catalysts supported on ceria–zirconia and ceria–zirconia/alumina in the calcined state and under a reactive CO+O2 atmosphere has been characterized by a combination of electron transmission microscopy, infrared and electron paramagnetic resonance spectroscopies, and the results obtained used to interpret the catalytic behavior displayed by the samples in the CO oxidation reaction. The Ce/Zr promoter enhances the catalytic properties of the noble metal by favoring the formation of the metallic state and through creation of anionic vacancies in the Ce–Zr component even from room temperature. The optimum promoting effect in the CO oxidation is observed for palladium particles in contact with three-dimensional-like Ce–Zr particles due to the appropriate nature and high number of the anion vacancies present at their surface. Compared with classical ceria-based systems, CO oxidation is here maximized for Pd-supported on the bulk material and not on mixed ceria-containing/alumina catalysts. These differences are discussed on the basis of the effect of the ceria and ceria–zirconia promoter particle size on the nature and number of active sites.read more
Citations
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Journal ArticleDOI
Pd/CeO2–TiO2 catalyst for CO oxidation at low temperature: a TPR study with H2 and CO as reducing agents
TL;DR: The results showed that PdO is finely dispersed on the supports with high surface area DRIFTS of CO adsorption further indicated that both Pd 2+ and Pd 0 species coexist in Pd/CeO 2, while only pd 0 is detected in Pdr 0 and Pdr 1 species in C CeO 2 and CeO 0 as mentioned in this paper, which may indicate that the special Pd-Ce-Ti interaction is favorable for the reduction of Pd o 2 and interfacial O 2 species.
Journal ArticleDOI
Preparation of catalysts from microemulsions and their applications in heterogeneous catalysis
TL;DR: The first implementation of water-in-oil (w/o) micro-emulsions for synthesis of nanoparticles was in this article, where they were used for oil recovery.
Journal ArticleDOI
Nanoparticle synthesis in engineered organic nanoscale reactors
TL;DR: In this paper, a review of the recent achievements in the synthesis of inorganic nanomaterials inside the spatially confined volume of individual micro- and submicroreactors (emulsions, micelles, organized thin films, polyelectrolyte capsules, etc.) are presented.
Journal ArticleDOI
Diesel Oxidation Catalysts
April Russell,William S. Epling +1 more
TL;DR: The diesel oxidation catalyst (DOC) has been part of diesel exhaust systems since regulations were introduced to limit the amount of harmful emissions released to the environment from diesel engines as discussed by the authors, while active hydrocarbon oxidation can also be used to generate exotherms required for downstream components.
Journal ArticleDOI
Dynamic in situ observation of rapid size and shape change of supported Pd nanoparticles during CO/NO cycling
TL;DR: A novel, non-oxidative redispersion mechanism is demonstrated, and a model to bridge the structural and reactive functions of supported Pd catalysts is suggested, to improve the behaviour of supported precious-metal catalysts for environmentally and economically important processes.
References
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Journal ArticleDOI
Catalytic Properties of Ceria and CeO2-Containing Materials
TL;DR: A survey of the use of cerium oxide and CeO2-containing materials as oxidation and reduction catalysts is presented in this paper, with a special focus on catalytic interaction with small molecules such as hydrogen, carbon monoxide, oxygen, and nitric oxide.
Journal ArticleDOI
Use of CeO2-based oxides in the three-way catalysis
TL;DR: In this paper, the use of CeO 2 -based materials in the automotive three-way catalysts (TWCs) is considered, and the multiple roles of COO 2 as a TWC promoter and in particular the oxygen storage/release capacity (OSC) are critically discussed.
Book ChapterDOI
Characterization and Reactivity of Molecular Oxygen Species on Oxide Surfaces
M. Che,A.J. Tench +1 more
TL;DR: This chapter discusses the characterization and reactivity of mononuclear oxygen species on oxide surfaces and there is evidence from the examples for some of the species that are stable at much higher temperatures and may play an important role in catalytic reactions.
Journal ArticleDOI
Catalytic converters: state of the art and perspectives
TL;DR: In this paper, the authors give an overview of the advanced technologies currently used for abating emissions from the gasoline and diesel internal combustion engines. And the challenges towards the end of the 20th century into the 21st century are discussed.
Journal ArticleDOI
The application of CeZr oxide solid solution to oxygen storage promoters in automotive catalysts
TL;DR: In this article, the complex oxides in the CeO2ZrO2 system were examined for the improvement of oxygen storage capacity in automotive catalysts, and the formation of CeO 2 Zr oxide solid solution improved the thermal stability and activity of the system.