Electrochemical study of niobium fluoride and oxyfluoride complexes in molten LiF-KF-K2NbF2 bath

被引：44

作者：

Van, V ^{[1
]}

Silny, A ^{[1
]}

Híves, J ^{[1
]}

Danek, V ^{[1
]}

机构：

[1] Slovak Acad Sci, Inst Inorgan Chem, Bratislava 84236, Slovakia

来源：

ELECTROCHEMISTRY COMMUNICATIONS | 1999年 / 1卷 / 07期

关键词：

niobium; molten fluorides; electrodeposition; cyclic voltammetry; reduction mechanism;

D O I：

10.1016/S1388-2481(99)00060-0

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

The reduction of niobium in an equimolar molten mixture of LiF and KF has been investigated using a cyclic voltammetric technique. A two-step mechanism of reduction of niobium in LiF-KF melt is proposed. The influence of oxide ions on the reduction has been studied and it was found to strongly influence the redox properties and structure of niobium ions in the melt. The presence of oxide ions caused the formation of the mono-oxyfluoride complex [Nb(V)OF5](2-). The formation of the mono-oxyfluoride complex was not complete at 720 degrees C. Free oxide ions caused an appearance of di-oxyfluoride complex. In the redundant oxide ions the di-oxyfluoride complex was converted to [Nb(IV)O2F](-) by a redox reaction. (C) 1999 Elsevier Science S.A. All rights reserved.

引用

页码：295 / 300

页数：6

共 16 条

[1] ELECTRODEPOSITION OF NIOBIUM FROM FLUORONIOBATE K2NBF7 SOLUTIONS IN FUSED NACL-KCL [J].

BARHOUN, A ;

BERGHOUTE, Y ;

LANTELME, F .

JOURNAL OF ALLOYS AND COMPOUNDS, 1992, 179 :241-252

[2]

CHAMELOT P, 1997, ELECTROCHIM ACTA, V43, P607

[3]

CHEMLA M, 1973, B SOC CHIM FR, P853

[4] THE INFLUENCE OF OXIDE ON THE ELECTRODEPOSITION OF NIOBIUM FROM ALKALI FLUORIDE MELTS [J].

CHRISTENSEN, E ;

WANG, XD ;

VONBARNER, JH ;

OSTFOLD, T ;

BJERRUM, NJ .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1994, 141 (05) :1212-1220

[5]

KHALIDI A, 1991, MATER SCI FORUM, V73, P421, DOI 10.4028/www.scientific.net/MSF.73-75.421

[6] CATHODIC PROCESSES AT ELECTROLYSIS OF CHLORIDE-FLUORIDE AND OXYFLUORIDE MELTS OF NIOBIUM [J].

KONSTANTINOV, VI ;

POLYAKOV, EG ;

STANGRIT, PT .

ELECTROCHIMICA ACTA, 1981, 26 (03) :445-448

[7] The influence of oxide on the electrochemical processes in K2NbF7-NaCl-KCl melts [J].

Lantelme, F ;

Berghoute, Y ;

vonBarner, JH ;

Picard, GS .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1995, 142 (12) :4097-4102

[8]

LOS P, 1989, B ELECTROCHEM, V5, P820

[9] The redox chemistry of niobium(V) fluoro and oxofluoro complexes in LiF-NaF-KF melts [J].

Matthiesen, F ;

Christensen, E ;

vonBarner, JH ;

Bjerrum, NJ .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1996, 143 (06) :1793-1799

[10]

MCDONALD DD, 1977, TRANSIENT TECHNIQUES, P191

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