The potential use of uranium oxides and uranium–bismuth mixed oxides in catalysis

Collette, H.; Deremince-Mathieu, V.; Gabélica, Z.; Nagy, J.B.; Derouane, Éric G.; Verbist, J.

doi:10.1039/f29878301263

Cited by 29 publications

(12 citation statements)

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“…The combination of above mentioned characteristics, i.e., formation of multiple phases in a wide range of O/U ratio from 2 to 3, the prevalence of microstructural defects because of oxygen non-stoichiometry, resistance to sintering, and low reduction/oxidation potentials make the oxides of uranium as efficient catalysts for various dedicated oxidation reactions, where the facile adsorption and storage of oxygen in bulk structure may play an important role [6,7]. It is therefore not surprising that a variety of applications have been reported in the literature where the oxides of uranium have been employed as active heterogeneous catalysts, as promoters and also as support of other catalysts.…”

Section: Preamblementioning

confidence: 99%

An overview of studies on the highly dispersed uranium oxide species occluded within mesoporous MCM-41 and MCM-48 host materials

Kumar

Gupta

2005

Catal Surv Asia

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Section: Preamblementioning

confidence: 99%

An overview of studies on the highly dispersed uranium oxide species occluded within mesoporous MCM-41 and MCM-48 host materials

Kumar

Gupta

2005

Catal Surv Asia

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“…The formation of highly defective (oxygen deficient) phases, crucial for the attainment of effective redox couples in such systems, is emphasized by the behavior of Bi 2 UO 6 in the oxidative demethylation of toluene . A high selectivity for this reaction is only achieved in the absence of gaseous oxygen; indeed this material can lose 50% of its lattice oxygen without substantial structural modification …”

Section: Introductionmentioning

confidence: 99%

“…4 A high selectivity for this reaction is only achieved in the absence of gaseous oxygen; indeed this material can lose 50% of its lattice oxygen without substantial structural modification. 5 The use of both bulk and supported uranium oxides in total oxidation reactions for pollution control has gathered interest, particularly in light of the work of Hutchings et al 6 who showed that U 3 O 8 is an extremely effective catalyst for the complete oxidation of a range of chlorinated organic compounds to carbon oxides, HCl, and water.…”

Section: Introductionmentioning

confidence: 99%

Effects of Precursor and Support Variation in the Genesis of Uranium Oxide Catalysts for CO Oxidation and Selective Reduction of NO: Synthesis and Characterization

et al. 2005

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A range of uranium oxide-based catalysts, derived from UO2(NO3)2.6H2O and UCl4 precursors, and supported on gamma-Al2O3, SiO2 and mesoporous H1SiO2, have been synthesized and then characterized using the following methods: isothermal nitrogen adsorption/desorption measurements, diffuse reflectance infrared spectroscopy (DRIFTS), gas titration of surface hydroxyl groups using Grignard reagents, U L(III) extended X-ray absorption fine structure (EXAFS), powder X-ray diffraction (PXRD), and thermogravimetric and differential thermal analysis. Brij76-templated H1SiO2 mesoporous silicas are found to be essentially stable under flowing oxygen after 16 h at 1073 K. At temperatures above this, however, extensive structural collapse, together with extensive dehydroxylation, ensues. Titration of the accessible hydroxyl group concentrations shows that in these materials the density of OH groups is considerably lower than in their amorphous counterparts. The adsorption of uranyl nitrate onto these dispersants results in a supported, and partially dehydrated, phase of the parent molecule with little obvious structural distortion; however, the adsorption of UCl4 leads to a complex adstructure which may best be described as U(O)2Cl2. The subsequent formation of the uranium oxide phase, nominally active for the oxidation of CO and selective reduction of NO (generally accepted to be U3O8), is found to be a considerable function of both the precursor and support system employed. Calcination of such systems to 1073 K results in extensive extrusion of the supported uranium phase from mesoporous supports, resulting in the formation of very large orthorhombic U3O8 domains. PXRD, however, shows that on amorphous SiO2 and gamma-Al2O3 similar treatment results in the formation of a hexagonal phase of U3O8. The formation of U3O8 is found to be promoted in mesoporous systems and by the presence of Cl in the catalyst make up. Some evidence is also found that suggests that a persistence of Cl limits the growth of U3O8 domains.

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“…The potential of uranium oxides as catalytic materials has been reviewed by Collette et al 2 Uranium is an actinide element and, with six valence electrons, is similar to chromium, molybdenum and tungsten. The ability to attain high coordination numbers makes for a promising catalytic material and indeed uranium has been used in applications such as Fischer-Tropsch synthesis, dehydrogenation and oxidation (ref.…”

mentioning

confidence: 99%

Novel supported uranium oxide catalysts for NOx abatement

Pollington¹,

Lee²,

Overton³

et al. 1999

Chem. Commun.

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The potential use of uranium oxides and uranium–bismuth mixed oxides in catalysis

Cited by 29 publications

References 1 publication

An overview of studies on the highly dispersed uranium oxide species occluded within mesoporous MCM-41 and MCM-48 host materials

An overview of studies on the highly dispersed uranium oxide species occluded within mesoporous MCM-41 and MCM-48 host materials

Effects of Precursor and Support Variation in the Genesis of Uranium Oxide Catalysts for CO Oxidation and Selective Reduction of NO: Synthesis and Characterization

Novel supported uranium oxide catalysts for NOx abatement

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