Preparation and characterization of uranium-bismuth mixed oxide catalysts

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

doi:10.1016/0304-5102(87)85035-6

Cited by 5 publications

(2 citation statements)

References 12 publications

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“…In fact, liquid bismuth has been used in a wide range of applications in the pyroprocessing of used nuclear fuels and the partitioning of minor actinides and long-lived fission products arising out of the backend of nuclear fuel cycles [27]. Uranium-based mixed oxides (as bismuth uranate) have promising properties as heterogeneous catalysts [30][31][32]. The crystal structures and properties of intermetallic phases in the U-Bi system have also been reported [33].…”

Section: Introductionmentioning

confidence: 99%

Uranosphaerite: Crystal structure, hydrogen bonding, mechanics, infrared and Raman spectroscopy and thermodynamics

Colmenero

Plášil

Němec

2020

Journal of Physics and Chemistry of Solids

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Section: Introductionmentioning

confidence: 99%

Uranosphaerite: Crystal structure, hydrogen bonding, mechanics, infrared and Raman spectroscopy and thermodynamics

Colmenero

Plášil

Němec

2020

Journal of Physics and Chemistry of Solids

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“…Bismuth(III) monouranate, Bi 2 U VI O 6 , is the only compound well characterized from a crystallographic point of view and has been prepared by several high-and lowtemperature procedures. [3][4][5][6][7] It was reported to exist in two closely related crystalline modifications. The room temperature form, α-Bi 2 UO 6 (space group C2) 8 undergoes a phase transition above 600 °C into the β-form (P3 ˉspace group).…”

Section: Introductionmentioning

confidence: 99%

Further insights into the chemistry of the Bi–U–O system

et al. 2016

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Cubic fluorite-type phases have been reported in the U(IV)O2-Bi2O3 system for the entire compositional range, but an unusual non-linear variation of the lattice parameter with uranium substitution has been observed. In the current extensive investigation of the uranium(iv) oxide-bismuth(iii) oxide system, this behaviour of the lattice parameter evolution with composition has been confirmed and its origin identified. Even under inert atmosphere at 800 °C, U(IV) oxidises to U(V)/U(VI) as a function of the substitution degree. Thus, using a combination of three methods (XRD, XANES and Raman) we have identified the formation of the BiU(V)O4 and Bi2U(VI)O6 compounds, within this series. Moreover, we present here the Rietveld refinement of BiU(V)O4 at room temperature and we report the thermal expansion of both BiU(V)O4 and Bi2U(VI)O6 compounds.

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XANES study on novel mixed valent A₂U₄O₁₂(A = K, Rb or Tl) uranates

Misra¹,

Lahiri²,

Mudher³

et al. 2008

X-Ray Spectrometry

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Alkali metal (Na, K, Rb, and Cs) uranates are likely to form in operating or transient reactor conditions by interaction of coolant/fission products with uranium oxide fuel. The valency of uranium in uranates formed in reactor operating conditions plays an important role in migration of fission products as well as in uranium diffusion in the fuel and thus determines fuel behavior during reactor operation. X-ray absorption near edge structure (XANES) measurements on uranates K 2 U 4 O 12 , Rb 2 U 4 O 12 , and Tl 2 U 4 O 12 have been made to determine the valency of uranium in these compounds. XANES analysis reveals that uranium is present in mixed valence state in these compounds, as U(V) and U(VI). The ratio of uranium (V) to (VI) states (determined from XANES analysis), in all the compounds, does not conform to 1 : 1 as required by their chemical formula. The reason for this mismatch may be the instability of U(V) state during sample preparation in these compounds as well as reference compounds.

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Preparation and characterization of uranium-bismuth mixed oxide catalysts

Cited by 5 publications

References 12 publications

Uranosphaerite: Crystal structure, hydrogen bonding, mechanics, infrared and Raman spectroscopy and thermodynamics

Uranosphaerite: Crystal structure, hydrogen bonding, mechanics, infrared and Raman spectroscopy and thermodynamics

Further insights into the chemistry of the Bi–U–O system

XANES study on novel mixed valent A₂U₄O₁₂(A = K, Rb or Tl) uranates

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Preparation and characterization of uranium-bismuth mixed oxide catalysts

Cited by 5 publications

References 12 publications

Uranosphaerite: Crystal structure, hydrogen bonding, mechanics, infrared and Raman spectroscopy and thermodynamics

Uranosphaerite: Crystal structure, hydrogen bonding, mechanics, infrared and Raman spectroscopy and thermodynamics

Further insights into the chemistry of the Bi–U–O system

XANES study on novel mixed valent A2U4O12(A = K, Rb or Tl) uranates

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XANES study on novel mixed valent A₂U₄O₁₂(A = K, Rb or Tl) uranates