Pure and Applied Chemistry

Abstract: The processes of refractory metal complex electroreduction in transition from chloride to chloride–fluoride and oxofluoride melts have been studied. Decrease of the stage number of process complex electroreduction to metal and the possibility of a large number of electrons transferred in a single electrochemical stage on increasing the melt basicity has been established. It was shown that decreasing the stage number of electrode processes can be achieved by the change in anion composition (the first coordination sphere) and, in a number of cases, by the change in the cation composition (the second coordination sphere). With the melt basicity increase, a transition from reversible processes of the complex to metal discharge irreversible ones is observed, as a rule. The knowledge of electrode and chemical reactions accompanying the electroreduction of refractory metals and the study of the processes of alloy formation allow us to obtain novel niobium compounds and functional materials.