Development of an electrochemistry apparatus for the heaviest elements

Abstract

Electrochemistry / Flow electrolytic cell / Chemically modified electrode / Redox reaction Summary. We developed a new apparatus for the study of electrochemical properties of the heaviest elements. The apparatus is based on a flow electrolytic cell combined with column chromatography. Glassy-carbon fibers modified with Nafion perfluorinated cation-exchange resin are used as a working electrode as well as a cation-exchanger. The elution behavior of 139 Ce with the number of 10 10 atoms in 0.1 M ammonium α-hydroxyisobutyric acid solution from the column electrode was investigated at the applied potentials of 0.2-1.0 V versus the Ag/AgCl reference electrode in 1.0 M LiCl. It was found that 139 Ce 3+ is successfully oxidized to 139 Ce 4+ even with tracer concentration at around the redox potential determined by cyclic voltammetry for the macro amounts of Ce with 10 17 atoms (10 −3 M). The present oxidation reaction and separation of Ce 4+ was accomplished within a few minutes.

Chemical properties of rutherfordium (Rf) and dubnium (Db) in the aqueous phase

“…These results confirm that Rf is a member of the group-4 elements in the Periodic Table [7][8][9][10]. On the contrary, fluoride complex formation of Rf is significantly different from that of the homologs Zr and Hf, demonstrating a surprising behaviour of Rf [15][16][17][18]. Here, we summarize the fluoride complex formation studies of Rf performed with ARCA II and AIDA.…”

“…The successive fluoride complex formation of cationic species of Zr, Hf, and Rf was investigated through cation-exchange chromatography with ARCA II at the Philips Cyclotron, Paul Scherrer Institute [15] and with AIDA at the JAEA tandem accelerator [16][17][18]. The results demonstrated that the distribution coefficient, K d , of Rf in mixed solution of HF/0.10 M HNO 3 decreases with increasing concentration of the fluoride ion, [F − ], indicating the consecutive formation of neutral and/or anionic fluoride complexes of Rf as those of homologs.…”

“…Anionic fluoride complexation has been studied in mixed HF/HNO 3 solutions (dilute HF concentration) [17]. Figure 1a …”

“…Advanced theoretical model calculations have already provided quantitative predictions [31]. Preparations have started to measure the redox potential of hexavalent Sg [32]; a complex and continuously working system is envisioned which consists of an electrochemistry apparatus [33,34] for the potentially controlled Sg reduction connected to a separation device like SISAK for the extraction and a flow-through liquid-scintillation detection system [35]. By means of a newly designed interface [36], this shall be coupled with a recoil separator like GARIS (Gas-filled Recoil Ion Separator) at RIKEN [37].…”

Measurement of the Md3+/Md2+ Reduction Potential Studied with Flow Electrolytic Chromatography

“…Very recently, we have developed a novel method of electrolytic column chromatography available for single ions. 15 Carbon fibers modified with a Nafion perfluorinated ionexchange resin were employed as a working electrode as well as a cation exchanger. This technique was successfully applied to the oxidation of nobelium (No).…”