화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.163, No.14, H1113-H1121, 2016
Voltammetric Studies on the Complexing Behavior of Eu(III) with Acidic Extractants in 1-Butyl-1-methylpyrrolidinium Bis(trifluoromethanesulfonyl) imide
Di(2-ethylhexyl) phosphoric acid (D2EHPA) and diglycolamic acids (HDGA) has been proposed for the mutual separation of lanthanides and actinides at the back end of nuclear fuel cycle. The electrochemical behavior of Eu(III) in the room temperature ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide ([C(4)mpy][NTf2]) was studied in the presence and absence of D2EHPA and HDGA by various transient electrochemical techniques. The cyclic voltammogram of Eu(III) in [C(4)mpy][NTf2] recorded at glassy carbon electrode exhibited a prominent quasi-reversible reduction wave at -0.40 V (vs. Fc/Fc(+)) was due to the reduction of Eu(III) to Eu(II). The cathodic peak current was lowered and the cathodic peak potential shifted cathodically in the presence of ligands, due to the co-ordination of Eu (III) with ligands in ionic liquid phase. The stability constant and stoichiometry of Eu(III)-ligand complex was determined from the cyclic voltammograms recorded at various ligand concentrations. The Eu (III) diffusion coefficient was determined to be in the range of similar to 10(-11) m(2)/s by various electrochemical methods and the charge transfer rate constant (k(s), m/s) for the electron transfer reaction across the electrode - electrolyte inter phase was determined to be in the range of similar to 10(-7) m/s by cyclic voltammetry. (C) 2016 The Electrochemical Society. All rights reserved.