16065-90-0Relevant academic research and scientific papers
Photochemical Electron Transfer from Cerous Ions to the Lowest Excited State of Uranyl Ions in Aqueous Media, Studied by Laser Photolysis
Rosenfeld-Grunwald, T.,Brandels, Marek,Rabani, Joseph
, p. 4745 - 4750 (1982)
A high-intensity beam of a Nd laser at 353.3 nm was used to produce the first excited state of the uranyl ion.Cerous ions, in acidic aqueous solutions,were found to react with it.The products of this reaction are ceric ions and uranium(V) ions.The absorption of the Ce(IV) ions was followed and the yields and decay kinetics of the ions were studied.The quantum yield of Ce(IV) formation is 0.85 +/- 0.15, 1.00 +/- 0.2, and 0.95 +/- 0.25 in 0.1-0.5 M H2SO4, 0.57-2 M HNO3, and 2 M HClO4, respectively.The photochemical electron transfer is followed by a reaction of the products to produce the ground states of the initial reactants by a second-order reaction.The rate constant of this reaction is 5 * 106 M-1 s-1 in 0.1-0.5 M H2SO4, ca. 2 * 107 M-1 s-1 in 2 M HNO3, and ca. 3 * 107 M-1 s-1 in 2 M HClO4.The interpretation of the photochemical results is supported by pulse radiolysis experiments.
Experimental and Theoretical Studies of a Coupled Chemical Oscillator: Phase Death, Multistability, and In-Phase and Out-of-Phase Entrainment
Crowley, Michael F.,Epstein, Irving R.
, p. 2496 - 2502 (1989)
The oscillatory Belousov-Zhabotinskii reaction with acetylacetone as substrate has been studied in a pair of stirred tank reactors coupled by mass flow.The inputs to the two cells, and hence the uncoupled oscillation frequencies, are slightly different.De
Dissolution of actinide oxides in HNO3 using a concentrated ozone-oxygen mixture in the presence of Ce(IV) ions
Gelis,Shumilova,Ershov,Maslennikov,Mulyutin,Seliverstov
, p. 250 - 255 (2011)
Accumulation of Ce(IV) in HNO3 solutions as a result of Ce(III) oxidation with an ozone-oxygen mixture (OOM) was studied. An increase in the ozone concentration in OOM from 30 to 180 mg dm-3 leads to a considerable increase in the rate of Ce(III) oxidation to Ce(IV). With concentrated OOM, the Ce(III) to Ce(IV) oxidation yield of two ions per ozone molecule is attained. An increase in the steady-state concentration of Ce(IV) in the solution leads to considerable acceleration of the dissolution of highly calcined UO2.
Hydrolysis of tetravalent cerium for a simple route to nanocrystalline cerium dioxide: An in situ spectroscopic study of nanocrystal evolution
Ikeda-Ohno, Atsushi,Hennig, Christoph,Weiss, Stephan,Yaita, Tsuyoshi,Bernhard, Gert
, p. 7348 - 7360 (2013)
Despite the rapid developments in recent nanocrystal research and their expanding applications, the evolution mechanism of nanocrystals remains veiled for the most part due to the lack of appropriate analytical techniques. Here we demonstrate one promising multi-spectroscopic approach for the in situ investigation of nanocrystal evolution. That is, the formation of nanocrystalline cerium dioxide (NC-CeO2) has been probed by dynamic light scattering (DLS), X-ray absorption spectroscopy (XAS) and high-energy X-ray scattering (HEXS). The obtained results indicate that the fine colloidal particles of NC-CeO2 are formed in an acidic aqueous solution simply through the hydrolysis of the initial precursor of small oligomer Ce IV species. This information on how NC-CeO2 evolves is fundamental to simplifying and alleviating the synthetic strategy for NC-CeO2 production. Nanocrystal evolution: A multi-spectroscopic approach has revealed that the hydrolysis of tetravalent cerium (Ce IV) produces a colloidal solution of fine cerium dioxide (CeO 2) nanocrystals (see figure). A simple synthetic concept of nanocrystalline metal oxides is proposed based on the obtained results. Copyright
Photoelectrochemical reaction for the efficient production of hydrogen and high-value-added oxidation reagents
Fuku, Kojiro,Wang, Nini,Miseki, Yugo,Funaki, Takashi,Sayama, Kazuhiro
, p. 1593 - 1600 (2015/05/20)
A porous and thick photoelectrode of WO3 in the monoclinic phase was prepared to realize the recovery of H2 and high-value-added oxidation reagents with efficient solar energy conversion. The WO3 photoelectrode enabled the efficient production and accumulation of O2, S2O82-, Ce4+, and IO4- as oxidation products. Most notably, S2O82-, which possesses the highest oxidizability among all the peroxides, was generated with high applied bias photon-to-current efficiency (2.2 %) and faraday efficiency (≈100 %) upon irradiation from the back side of the photoelectrode. The design of a tandem photoelectrode system combining a dye-sensitized solar cell (DSSC) was also challenged for the realization of this photoelectrode system without external bias. A high solar energy conversion efficiency (5.2 %) was achieved in the tandem system comprising the WO3 photoelectrode connected to two DSSCs with a near-IR-utilizing dye in series for the production of H2 and S2O82-.
Growth of spherulitic crystal patterns in a Belousov-Zhabotinski type reaction system
Yadav, Narendra,Srivastava
, p. 1080 - 1087 (2011/07/08)
The growth of spherulitic crystal patterns in a Belousov-Zhabotinski (BZ) type reaction system by using acetyl acetone (AA)-succinic acid (SA) as dual organic substrates has been reported. The reaction system in the liquid phase has been found to show concentric ring-like wave patterns. A colloidal phase composed of numerous fine particles has also been observed during reaction. The solid phase nucleation has been found to occur in the colloidal phase, which leads to the formation of some stable nucleus centers. The solid phase nucleus has been found to grow in symmetric crystal patterns, with the progress of reaction, exhibiting spherulitic morphology. The possible growth behavior of spherulites has also been discussed. The spherulitic structure composed of fine crystal fibrils diverging from a common center have been observed by a scanning electron microscopy (SEM) technique. The polymorphic crystalline phase, found in spherulites has been supported by thermal characterization (TGA/DTA) and X-ray diffraction (XRD) patterns of crystal materials. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2011.
One- versus two-electron oxidation with peroxomonosulfate ion: reactions with iron(II), vanadium(II), halide ions, and photoreaction with cerium(III)
Lente, Gabor,Kalmar, Jozsef,Baranyai, Zsuzsa,Kun, Aliz,Kek, IIdikoe,Bajusz, David,Takacs, Marcell,Veres, Lilla,Fabian, Istvaen
, p. 1763 - 1773 (2009/06/17)
The kinetics of the redox reactions of the peroxomonosulfate ion (HSO 5-) with iron(ll), vanadium(IV), cerium(lll),chloride, bromide, and iodide ions were studied. Cerium(lll) is only oxidized upon illumination by UV light and cerium
Calorimetric study of the component steps of oscillating chemical reactions
Agreda,Barragan,Gomez
, p. 875 - 881 (2008/10/09)
The complexity of oscillating chemical reactions makes difficult a direct calorimetric study of them. It is more advantageous to carry out studies of the component steps and then try to put the parts together. Here, a mass-flow heat conduction calorimeter was used to study component reactions of two of the principal chemical oscillators. The studied reactions were: the net reaction of the inorganic set of the Belousov-Zhabotinsky reaction (BrO3; -+4Ce3++5H+?4Ce 4++HOBr+2H2O), and the Dushman reaction (IO 3-+5I-+6H+?3I 2+3H2O), which is a component of the Bray-Liebhafsky oscillator. The experimental values of the enthalpies of these two reactions are reported in this work.
A study on non-faradaic yields of anodic contact glow discharge electrolysis using cerous ion as the OH? scavenger: An estimate of the primary yield of OH? radicals
Sengupta, Susanta K.,Singh, Rajeshwar,Srivastava, Ashok K.
, p. 558 - 560 (2007/10/03)
Chemical yields of contact glow discharge electrolysis (CODE) show strong deviations from faradaic behaviour. The products are novel for normal electrolysis and yields significantly exceed the Faraday law value. Anodic CODE gives rise to Ce4+ and H2O2 in the anolyte in yields significantly exceeding the faradaic value besides the faradaic yield of O2. The relative yield of Ce4+ and H2O2 depends on the concentration of Ce3+ and the quantity of electricity passed. A kinetic analysis of the variation of the initial differential yield of Ce4+, G0 (Ce4+) with the concentration of Ce3+ after applying certain approximations leads to an estimate of the generation of 12 moles of OH? radicals in the liquid phase reaction zone of anodic CGDE for the passage of each mol electron of electricity.
Photo-induced Oxidation of Ce(III) with Water in Deaerated Carbonate Solutions
Shilov,Yusov,Penninov
, p. 1210 - 1215 (2008/10/08)
Light irradiation of Ce(III) contained in deaerated solutions of potassium, sodium, and ammonium carbonates and bicarbonates results in a gradual accumulation of Ce(IV). The oxidation yield after 3-4 h of irradiation is somewhat affected by the initial Ce(III) concentration and pH and is, in many cases, as high as 80-85%. All solutions, and particularly the bicarbonate ones, exhibit the effects associated with Ce(III) hydrolysis. This results in a retarded oxidation and a reduced oxidation yield. The irradiation leads to a reduction of Ce(IV) contained in the solutions, with the yield not exceeding several percent. The mechanisms of photoinduced reactions are discussed. Photooxidation of Ce(III) and photoreduction of Ce(IV) occur through the formation of cerium excimers.
