Studies of the Ce(III)/Ce(IV) couple in multiphase systems containing a phase transfer reagent—II. indirect oxidations and the electrolytic preparation of ceric nitrate

Pletcher, Derek; Valdés, E

doi:10.1016/0013-4686(88)80168-3

Cited by 21 publications

(8 citation statements)

References 21 publications

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“…Dichloromethane was employed to extract the product from the two-phase reaction mixture. Aiming to develop similar processes, the extraction of products from dichloromethane and n-hexane oxidation by Ce(IV) using tetrabutylammonium and tributylphosphate ions was investigated [59,103], and the regeneration in an undivided cell was achieved with constant extraction of Ce(IV) with ethylhexylphosphoric acid in kerosene [65]. Nevertheless, the use of planar electrodes severely limited the operational current density.…”

Section: Mediated Electrosynthesismentioning

confidence: 99%

Electrochemical redox processes involving soluble cerium species

Arenas

León

Walsh

2016

Electrochimica Acta

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Anodic oxidation of cerous ions and cathodic reduction of ceric ions, in aqueous acidic solutions, play an important role in electrochemical processes at laboratory and industrial scale. Ceric ions, which have been used for oxidation of organic wastes and off-gases in environmental treatment, are a wellestablished oxidant for indirect organic synthesis and specialised cleaning processes, including oxide film removal from tanks and process pipework in nuclear decontamination. They also provide a classical reagent for chemical analysis in the laboratory. The reversible oxidation of cerous ions is an important reaction in the positive compartment of various redox flow batteries during charge and discharge cycling. A knowledge of the thermodynamics and kinetics of the redox reaction is critical to an understanding of the role of cerium redox species in these applications. Suitable choices of electrode material (metal or ceramic; coated or uncoated), geometry/structure (2-or 3-dimensional) and electrolyte flow conditions (hence an acceptable mass transport rate) are critical to achieving effective electrocatalysis, a high performance and a long lifetime. This review considers the electrochemistry of soluble cerium species and their diverse uses in electrochemical technology, especially for redox flow batteries and mediated electrochemical oxidation.

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Section: Mediated Electrosynthesismentioning

confidence: 99%

Electrochemical redox processes involving soluble cerium species

Arenas

León

Walsh

2016

Electrochimica Acta

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“…[18] reports the D value for Ce III oxidation decreases from 8.8*10 −6 to 6.9*10 −6 cm 2 .s −1 as the acidity of supporting electrolyte increases from 1 M to 6 M HNO 3 . The factor contributing to the decrease in D value is due to the increase in solution viscosity arising out of the higher concentration of the supporting acid electrolytes …”

Section: Resultsmentioning

confidence: 99%

“…Further, preferential oxidation of the fuel can be achieved when Ce III / Ce IV is used as the redox couple due to the stability of Ce IV when compared to the most powerful redox catalyst Ag II , up to a temperature of about 363 K, which helps in minimizing the side reaction of oxidizing water molecules in the electrolyte by Ce IV . The kinetic parameters and the electrochemical behavior of Ce III / Ce IV couple have been investigated in H 2 SO 4 and HNO 3 media at lower concentrations of Ce III as well as the acid media by different researchers . Acidity of the electrolyte for electrochemical generation of Ce III to Ce IV play a vital role.…”

Section: Introductionmentioning

confidence: 99%

Studies on Electrochemical Generation of Ceric Ions in Nitric Acid Medium

et al. 2019

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Cerous/ceric redox couple is considered as a potential Mediated Electro Oxidative (MEO) catalyst in the electro-oxidative dissolution of difficult-to-dissolve trans-uranic elements in the concentrated nitric acid medium. The electrochemical oxidation behavior of Ce III in 11.5 M HNO 3 was investigated by cyclic voltammetry (CV) using two different working electrodes platinum (Pt) and glassy carbon (GC) at 298 K. At higher acidity, cerous to ceric oxidation on GC working electrode was found to be a reversible process contrary to a quasi-reversible observed at Pt working electrode. To compare the current efficiency in electrochemical cells for the oxidation of Ce III ions, lab and bench scale oxidation of 0.05 and 0.5 M Ce III in 11.5 M nitric acid was performed in divided and undivided cell assemblies using Pt electroplated Ti (PET) or pure Pt gauze as anodes. Almost 100% yield for Ce IV could be achieved in divided cells and under identical conditions; the conversion efficiency was 30% lower in undivided cells. These studies revealed the concentration dependence of Ce III besides cell potential and temperature on the rate of oxidation.

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“…The oxidation with cerium(IV), in particular, gives high naphthoquinone selectivities, with yields as high as 98 % [23]. Phase-transfer catalysts increase the rate of reaction [19], [20], [27]. Chemical oxidizing reagents can be regenerated electrochemically.…”

Section: Productionmentioning

confidence: 99%

“…1,4-Naphthoquinone can alternatively be obtained in the liquid phase in greater than 90 % yield by oxidation of naphthalene or its derivatives. The following oxidizing agents have been used on a preparative scale: chromic acid [13], chromium trioxide [14], lead dioxide [15], manganese(II) sulfate [16], ammonium peroxodisulfate [17][18][19], tetrabutylammonium nitrate in nitric acid [20], and cerium(IV) compounds [21][22][23][24][25][26][27]. The oxidation with cerium(IV), in particular, gives high naphthoquinone selectivities, with yields as high as 98 % [23].…”

Section: Productionmentioning

confidence: 99%