Catalytic dissolution of ceria under mild conditions

Virot, Matthieu; Chave, Tony; Horlait, Denis; Clavier, Nicolas; Dacheux, Nicolas; Ravaux, Johann; Nikitenko, Sergey I.

doi:10.1039/c2jm31996a

Cited by 31 publications

(44 citation statements)

References 15 publications

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“…28,29 Sonochemical experiments were performed using 20 kHz ultrasonic processors purchased from Bioblock Scientific (Vibracell, 600 W, ATALANTE) and from Sonics & Materials (Vibracell, VCX 750, ICSM). The negative pressure glove box is equipped with thermostated "cup horn" tight reactors (50 or 100 mL) connected to a Lauda E210 cryostat from the outside of the enclosure.…”

Section: Sonochemical Experimentsmentioning

confidence: 99%

Sonochemical redox reactions of Pu(iii) and Pu(iv) in aqueous nitric solutions

et al. 2015

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The behavior of Pu(iv) and Pu(iii) was investigated in aqueous nitric solutions under ultrasound irradiation (Ar, 20 kHz). In the absence of anti-nitrous reagents, ultrasound has no effect on Pu(iv), while Pu(iii) can be rapidly oxidized to Pu(iv) due to the autocatalytic formation of HNO(2) induced by HNO(3) sonolysis. In the presence of anti-nitrous reagents (sulfamic acid or hydrazinium nitrate), Pu(iv) can be sonochemically reduced to Pu(iii). The reduction follows a first order reaction law and leads to a steady state where Pu(iv) and Pu(iii) coexist in solution. The reduction process is attributed to the sonochemical generation of H(2)O(2) in solution. The kinetics attributed to the reduction of Pu(iv) are however higher than those related to the formation of H(2)O(2) which, after several hypotheses, is explained by the sonochemical erosion of the titanium-based sonotrode. Titanium particles thereby generated can be solubilized under ultrasound and generate Ti(iii) as an intermediate species, a strong reducing agent able to react with Pu(iv).

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Section: Sonochemical Experimentsmentioning

confidence: 99%

Sonochemical redox reactions of Pu(iii) and Pu(iv) in aqueous nitric solutions

et al. 2015

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“…[7] In the case of ceria this is based on high oxygen conductivity and tolerance of non-stoichiometry CeO 2Àx due to the ability of Ce to adjust to oxygen vacancies by reduction to Ce 3 + .D amage is observed as partial amorphisation, lattice swelling, dislocation formation,a nd vacancy generation anda gglomeration with void formation. [10] In this context it becomesu rgentt os tudy the combination of the two above processes:1 )irradiation of dry ceria, and 2) wet-chemical dissolution of ceria, into one combined experiment with nanometer scale in situ observation of wet ceria irradiated in situ. [10] In this context it becomesu rgentt os tudy the combination of the two above processes:1 )irradiation of dry ceria, and 2) wet-chemical dissolution of ceria, into one combined experiment with nanometer scale in situ observation of wet ceria irradiated in situ.…”

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Giant Radiolytic Dissolution Rates of Aqueous Ceria Observed in Situ by Liquid‐Cell TEM

2017

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The dynamics of cerium oxide nanoparticle aqueous corrosion are revealed in situ. We use innovative liquid-cell transmission electron microscopy (TEM) combined with deliberate high-intensity electron-beam irradiation of nanoparticle suspensions. This enables life video-recording of materials reactions in liquid, with nm resolution. We introduce image quantification to measure detailed rates of dissolution as a function of time and particle size to be compared with literature data. Giant dissolution rates, exceeding any previous reports for chemical dissolution rates at room temperature by many orders of magnitude, are discovered. The reasons for this accelerated dissolution are outlined, including the importance of the radiolysis of water preceding the ceria attack. Electron-water interaction generates radicals, ions, and hydrated electrons, which assist in hydration and reductive dissolution of oxide minerals. The presented methodology has the potential to become a novel accelerated testing procedure to compare multiple nanoscale materials for relative aqueous durability. The ceria-water system is of crucial importance for the fields of catalysis, abrasive polishing, environmental remediation, and as simulant for actinide oxide behaviour in contact with liquid for nuclear engineering.

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“…In the case of PEO coatings formed in electrolytes containing CeO 2 , the source of Ce 3+ during the degradation process of the coating is quite limited due mainly to two effects: i) the slow dissolution rate of CeO 2 [55] and ii) the…”

Section: Accepted Manuscriptmentioning

confidence: 99%