Cathodic behaviour of europium (III) on glassy carbon, electrochemical formation of Al4Eu, and oxoacidity reactions in the eutectic LiCl–KCl

Elucidation of Electrode Reaction of EuCl3in LiCl-KCl Eutectic Melts through CV Curve Analysis

“…The value of the standard rate constant (2.2 × 10 −2 cm/s) was 4.5 times larger than the value (4.9 × 10 −3 cm/s) reported by Bermejo et al. 12 When considering the simulated curves shown in Figure 3, it is thought that the k o value of 2.2 × 10 −2 cm/s is more reasonable. In case that the redox couples with the same structural properties are dissolved species, the transfer coefficient (a) value is between 0.4 and 0.6.…”

“…9-11 Among many lanthanide species, study on europium species in a molten salt has attracted much attention recently due to its peculiar characteristics. 12,18,19 Lanthanide oxides show very poor solubility in a molten salt media. 18 On the other hand, europium oxide (Eu 2 O 3 ) easily dissolves to form Eu(II) ions even though most of lanthanide ions exist as trivalent states in molten salts.…”

“…18 So far, few studies on the kinetic properties of europium species have been reported. Recently, Bermejo et al 12 reported the determination of a standard rate constant (k o ), transfer coefficient (α), and half-wave potential (E 1/2 ) for a redox reaction of Eu 3+ /Eu 2+ through a curve fitting of a single cyclic voltammogram using a simulation computer program (M271 COOL kinetic analysis software). In general, however, the characteristic parameters such as the formal potential, standard rate constant, and transfer coefficient for a given electrode reaction cannot be extracted from a single CV curve because there can be multiple interpretations of a CV curve.…”

Electrochemistry of Tm(III) and Yb(III) in Molten Salts

“…Special attention is devoted to rare earth elements (REE) mainly due to its neutronic poison effect and the high content into the spend fuel. In addition, REE have similar chemical properties [Bermejo et al, 2006[Bermejo et al, , 2007[Bermejo et al, , 2008a[Bermejo et al, , 2008bCastrillejo et al, 2005aCastrillejo et al, , 2005bCastrillejo et al, , 2005cCastrillejo et al, , 2009De Cordoba et al, 2004Kuznetsov et al, 2006;Smolenski et al, 2008aSmolenski et al, , 2008b] to those of actinides [Fusselman et al, 1999;Morss, 2008;Osipenko et al, 2010Osipenko et al, , 2011Roy et al, 1996;Sakamura et al, 1998;Serp et al, 2004Serp et al, , 2005aSerp et al, , 2005bSerp et al, , 2006Serrano & Taxil, 1999;Shirai et al, 2000] hence separation between these groups of elements is very difficult. For this reason, a good knowledge of the basic properties of REE in the proposed separation media is very important.…”

A comparative study of the cathodic behaviour of EuCl3 in two imidazolium chloride ionic liquids, the 1-butyl-3-methylimidazolium (C4mimCl) and the 1-ethyl-3-methylimidazolium (C2mimCl), on a glassy carbon electrode

“…The electroreduction of Eu(III) and Sm(III) has also been studied in molten chloroaluminates [22][23][24], molten chlorides (e.g. LiCl-KCl and CaCl 2 -NaCl) [25][26] and bis(trifluoromethylsulfonyl)imide (NTf 2 ) based ionic liquids [27] in all cases, the electroreduction of the respective Ln(III) to Ln(II) takes place following the sequence of the cathodic potential: Sm(III) > Eu(III). More recently the electroreduction of Eu(III) has been studied by Rama et al [28] in the 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C 6 mim)NTf 2 containing tri-nbutyl phosphate and N,N-dihexyloctanamide ligands, the electrochemical system Eu(III)/Eu(II), free of any adsorption process, has been found quasi-reversible being the activation energy for Eu (III) diffusion 88 kJ mol − 1 .…”