On the volatility of ruthenium

Hölgye, Z.; Krivanek, M.

doi:10.1007/bf02520633

Cited by 11 publications

(8 citation statements)

References 9 publications

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“…Besides aerosol filtration, gaseous sampling was conducted at some locations (Austria, Sweden, Italy, and Poland), thus allowing checking for the presence of gaseous Ru species. Ruthenium may be present in volatile forms, especially in the form of ruthenium tetroxide, RuO 4 (15). Since gaseous RuO 4 is a highly reactive and strong oxidizer, it is expected to rapidly nucleate into particulate and low volatile RuO 2 .…”

Section: Resultsmentioning

confidence: 99%

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Masson

Steinhäuser

Zok

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

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In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (106Ru). The range of concentrations varied from some tenths of µBq·m−3 to more than 150 mBq·m−3. The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne 106Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location. Based on airborne concentration spreading and chemical considerations, it is possible to assume that the release occurred in the Southern Urals region (Russian Federation). The 106Ru age was estimated to be about 2 years. It exhibited highly soluble and less soluble fractions in aqueous media, high radiopurity (lack of concomitant radionuclides), and volatility between 700 and 1,000 °C, thus suggesting a release at an advanced stage in the reprocessing of nuclear fuel. The amount and isotopic characteristics of the radioruthenium release may indicate a context with the production of a large 144Ce source for a neutrino experiment.

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Section: Resultsmentioning

confidence: 99%

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Masson

Steinhäuser

Zok

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

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“…A detailed description of QCM theory may be found in various texts (21)(22)(23)(24). Assuming mass is rigidly bound; the measured shift in the resonant frequency is converted to a mass change via the Sauerbrey equation, Equation [1] ∆f = -C f ∆m [1] Where ∆f is the change in resonant frequency (Hz), ∆m is the mass change (g) and C f is the sensitivity constant. The value of C f can be determined from electrochemical deposition and dissolution of copper via cyclic voltammetry (25,26) we have found it to be 0.059 Hz (ng cm -2 ), which is in excellent agreement with a theoretical value of 0.056 Hz (ng cm -2 ) quoted by the manufacturer (Q-sense, Biolin Scientific, Manchester, UK).…”

Section: Electrochemical Microgravimetric Measurementsmentioning

confidence: 99%

Ruthenium Volatilisation from Reprocessed Spent Nuclear Fuel – Studying the Baseline Thermodynamics of Ru(III)

Johal¹,

Boxall²,

Gregson

et al. 2015

ECS Trans.

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Ruthenium is a fission product possessed of two relatively long lived isotopes, 103 Ru and 106 Ru, both of which form part of the Highly Active (HA) waste raffinate during spent nuclear fuel reprocessing. During reprocessing ruthenium, which may be in the form of the RuNO 3+ complex, encounters temperatures conducive to volatilization. Due rutheium's high specific radioactivity it is important to understand the mechanism by which volatilisation occurs. Here we use combined CV, RDE and electrochemical microgravimetry experiments in a study of the the RuCl 3 system for the first time. We do this in the interest of establishing NO-free Ru(III) baseline behaviour so as to support future studies on NO complexed ruthenium. Using wide aqueous solvent window carbon electrodes we have observed discrete oxidations to a solution phase Ru(III)-Ru(IV)-Ru(III) trimer, to solid RuO 2 and volatile RuO 4 . We have also observed and assigned discrete reductions of solid RuO 2 back to Ru(III) and Ru(III) reduction to ruthenium metal.

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“…On the other hand, RuO 2 is not an efficient oxidation catalyst for methane combustion, and under oxidizing conditions, RuO 2 is vulnerable to overoxidation to form volatile RuO 3 and RuO 4 above 500-600°C. [52] However, mixing 25 mol % or less of IrO 2 into RuO 2 improves the activity steeply and thermally stabilizes RuO 2 . Since Ru is significantly more abundant than Ir (30 t/a) and about eight times less expensive than Pd, RuO 2 with little IrO 2 could therefore be a promising option for catalytic methane combustion.…”

Section: Molecular Insightmentioning

confidence: 99%

Mixed Ru_xIr_1−xO₂ Supported on Rutile TiO₂: Catalytic Methane Combustion, a Model Study

et al. 2021

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With a modified Pechini synthesis, mixed Ru x Ir 1À x O 2 is grown on rutile-TiO 2 with full control of the composition x, where the preformed TiO 2 particles serve as nucleation sites for the active component. Catalytic and kinetic data of the methane combustion over Ru x Ir 1À x O 2 @TiO 2 and unsupported Ru x Ir 1À x O 2 catalysts reveal that the least active catalyst is RuO 2 @TiO 2 (onset temperature: 270°C), while the most active catalyst is Ru 0.25 Ir 0.75 O 2 with an onset temperature below 220°C. Surprisingly, even Ru 0.75 Ir 0.25 O 2 @TiO 2 is remarkably active in methane combustion (onset temperature: 230°C), indicating that little iridium in the mixed Ru x Ir 1À x O 2 oxide component already improves the activity of the methane combustion considerably. We conclude that iridium in the mixed Ru x Ir 1À x O 2 oxide enables efficient methane activation, while ruthenium promotes the subsequent oxidation steps of the methyl group to produce CO 2 . Kinetic data provide a reaction order in O 2 of zero, while that of methane is close to one, indicating that the methane activation is rate limiting. The apparent activation energy varies among Ru x Ir 1À x O 2 from 110 (x = 0) to 80 kJ • mol À 1 (x = 1). This variation in the apparent activation energy may be explained by the variation in adsorption energy of oxygen. Under the given reaction conditions the catalyst's surface is saturated with adsorbed oxygen and only if oxygen desorbs, methane can be activated and the methyl group can be accommodated at the liberated surface metal sites.

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On the volatility of ruthenium

Cited by 11 publications

References 9 publications

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Ruthenium Volatilisation from Reprocessed Spent Nuclear Fuel – Studying the Baseline Thermodynamics of Ru(III)

Mixed Ru_xIr_1−xO₂ Supported on Rutile TiO₂: Catalytic Methane Combustion, a Model Study

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On the volatility of ruthenium

Cited by 11 publications

References 9 publications

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017

Ruthenium Volatilisation from Reprocessed Spent Nuclear Fuel – Studying the Baseline Thermodynamics of Ru(III)

Mixed RuxIr1−xO2 Supported on Rutile TiO2: Catalytic Methane Combustion, a Model Study

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Mixed Ru_xIr_1−xO₂ Supported on Rutile TiO₂: Catalytic Methane Combustion, a Model Study