The oxidation mechanism of pure uranium in carbon monoxide between 700° and 1000°C

Ir, Whittle; Gerrish, Mrs.M.E.; Stobbs, J.J.; Buddery, J.H.

doi:10.1016/0022-5088(67)90183-x

Cited by 5 publications

(4 citation statements)

References 9 publications

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“…Reactions of uranium atoms with atmospheric components are of considerable interest due to the development of gas-phase separations involving atomic uranium. Mass spectrometric investigation and matrix isolation studies have focused on the oxidation of atomic uranium by molecular oxygen. − Recent investigations of laser-ablated uranium atom reactions with O 2 , N 2 , and NO have characterized the inserted OUO, NUN, and NUO molecules in solid argon. − Although reactions of solid uranium with carbon monoxide have been studied, − little is known about reaction intermediates.…”

Section: Introductionmentioning

confidence: 99%

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO^-, OUCCO, (η²-C₂)UO₂, and U(CO)_x (x = 1−6) Molecules in Solid Neon

et al. 1999

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Laser-ablated uranium atoms have been reacted with CO molecules during condensation with neon at 4 K. Absorptions at 1047.3 and 872.2 cm -1 are assigned to the CUO molecule formed from the insertion reaction that requires activation energy. Isotopic substitution shows that the upper band is largely U-C and the lower band mostly U-O in vibrational character. Absorptions at 2051.5, 1361.8, and 841.0 cm -1 are assigned to the OUCCO molecule, which is formed by the CO addition reaction to CUO and ultravioletvisible photon-induced rearrangment of the U(CO) 2 molecule. The OUCCO molecule undergoes further photochemical rearrangment to the (C 2 )UO 2 molecule, which is characterized by symmetric and antisymmetric OUO stretching vibrations at 843.2 and 922.1 cm -1 . The uranium carbonyls U(CO) x (x ) 1-6) are produced on deposition or on annealing. Evidence is also presented for the CUO -anion and U(CO) x -(x ) 1-5) anions, which are formed by electron capture. Relativistic density functional theoretical calculations have been performed for the aforementioned species, which lend strong support to the experimental assignments of the infrared spectra. It is predicted that CUO is a linear singlet molecule with the shortest U-C bond yet characterized, and it has a U-C triple bond with substantial U 5f character. The theoretical analysis also finds that a distorted tetrahedral geometry of (C 2 )UO 2 lies much lower in energy than either the bent/linear OUCCO structures or the U(CO) 2 uranium dicarbonyl.

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Section: Introductionmentioning

confidence: 99%

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO^-, OUCCO, (η²-C₂)UO₂, and U(CO)_x (x = 1−6) Molecules in Solid Neon

et al. 1999

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“…In literature, the majority is concentrated on physical metallurgy and mechanical properties of uranium alloys; only limited oxidation studies were recorded. Moreover, reports on oxidation of uranium inter-metallic compounds [59,62] are also found, which are not involved in our studies. Owing to its good performance in applications, the U-Nb system, which was not widely studied, was chosen for our exploration, and we are more interested in oxidation and hydrogenation of U-Nb alloy [27,70,[88][89][90].…”

Section: Reaction Of U-nb Alloy Under Different Conditionsmentioning

confidence: 71%

“…At low temperatures, both dissociative adsorption and molecular chemisorption of CO or/and CO 2 were observed on uranium surface, while only the former was found at higher temperatures (above about 300 K), which results in the formation of surface compounds [58]. However, the explanation of the surface compounds is not consistent [58,61,62]. Atomic carbon and oxygen were found on clean surface, and during depth profile, carbide was indentified as a result of reaction between uranium and carbon produced by the dissociation of CO and CO 2 .…”

Section: Reaction Of Uranium Metal Surface With Co and Comentioning

confidence: 85%

“…Significant progress has been made in the surface oxidation of U-O 2 and U-H 2 systems, while little work has been carried out on the surface reactions of uranium with CO and CO 2 [58][59][60][61][62], and even lesser on adsorption kinetics [39,[62][63][64]. The chemisorption and initial stages of chemical reaction of CO and CO 2 with uranium metal and intermetallic uranium were examined, and changes in chemical reactions were found to vary with temperature, gas partial pressure, exposure and electronic structure.…”

Section: Reaction Of Uranium Metal Surface With Co and Comentioning

confidence: 99%

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Recent advances in study of uranium surface chemistry in China

2014

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Uranium is very important in nuclear energy industry; however, uranium and its alloys corrode seriously in various atmospheres because of their chemical reactivities. In China, continuous investigations focused on surface chemistry have been carried out for a thorough understanding of uranium in order to provide technical support for its engineering applications. Oxidation kinetics of uranium and its alloys in oxidizing atmospheres are in good agreement with those in the literature. In addition to the traditional techniques, non-traditional methods have been applied for oxidation kinetics of uranium, and it has been verified that spectroscopic ellipsometry and X-ray diffraction are effective and nondestructive tools for in situ kinetic studies. The inhibition efficiency of oxidizing gas impurities on uranium hydrogenation is found to follow the order CO 2 > CO > O 2 , and the broadening of XPS shoulders with temperature in depth profile of hydrogenated uranium surface is discussed, which is not mentioned in the literature. Significant progress on surface chemistry of alloyed uranium (U-Nb and U-Ti) in hydrogen atmosphere is reported, and it is revealed that the hydrating nucleation and subsequent growth of alloyed uranium are closely connected with the surface states, underlying metal matrix, and it is microstructure-dependent. In this review, the recent advances in uranium surface chemistry in China, published so far mostly in Chinese language, are briefly summarized. Suggestions for further study are made.

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The oxidation of uranium in carbon dioxide and carbon monoxide (A review)

Pearce¹,

Ir²,

Hilton³

1969

Journal of Nuclear Materials

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The oxidation mechanism of pure uranium in carbon monoxide between 700° and 1000°C

Cited by 5 publications

References 9 publications

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO^-, OUCCO, (η²-C₂)UO₂, and U(CO)_x (x = 1−6) Molecules in Solid Neon

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO^-, OUCCO, (η²-C₂)UO₂, and U(CO)_x (x = 1−6) Molecules in Solid Neon

Recent advances in study of uranium surface chemistry in China

The oxidation of uranium in carbon dioxide and carbon monoxide (A review)

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The oxidation mechanism of pure uranium in carbon monoxide between 700° and 1000°C

Cited by 5 publications

References 9 publications

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO-, OUCCO, (η2-C2)UO2, and U(CO)x (x = 1−6) Molecules in Solid Neon

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO-, OUCCO, (η2-C2)UO2, and U(CO)x (x = 1−6) Molecules in Solid Neon

Recent advances in study of uranium surface chemistry in China

The oxidation of uranium in carbon dioxide and carbon monoxide (A review)

Contact Info

Product

Resources

About

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO^-, OUCCO, (η²-C₂)UO₂, and U(CO)_x (x = 1−6) Molecules in Solid Neon

Reaction of Laser-Ablated Uranium Atoms with CO: Infrared Spectra of the CUO, CUO^-, OUCCO, (η²-C₂)UO₂, and U(CO)_x (x = 1−6) Molecules in Solid Neon