ChemInform Abstract: Influence of Oxide on the Electrochemical Processes in K2NbF7-NaCl-KCl Melts.
Abstract
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract
The mechanism of electroreduction of K2NbF7 in NaCl-KCl melts as a function of the oxide ion content is studied by transient electrochemical techniques. The reduction of K2NbF7 at O/Nb molar ratio < 1 proceeds by a two-step reaction Nb(V) → Nb(IV) . fwdarw. Nb. In the presence of oxide ions niobium oxo complexes form which on reduction yield Nb and niobium suboxides such as NbO and Nb4O5. At molar O/Nb ratios > 1 a black layer, identified as NbO2 by XRD, appears at the electrode surface. Due to the high oxygen affinity of Nb, for the electrotwinning of Nb with < 10 ppm oxygen content from a solution of 0.1 M K2NbF7 in an NaCl-KCl melt, the oxygen content of the electrolyte must be kept below 15 ppm.
