Standard rate constants of charge transfer of Nb(V)/Nb(IV) redox pair in equimolar NaCl-KCl melt

Standard rate constants of charge transfer (k _s) on platinum and glassy carbon electrodes for Nb(V)/Nb(IV) redox pair in the NaCl-KCl-K₂NbF₇ melt are determined using the method of cyclic voltammetry in the temperature range of 973 to 1123 K. It is found that k _s increases with increasing temperature and when we pass from glassy carbon to platinum electrode. The “apparent” activation energies of charge transfer are determined; it is shown that the charge transfer between the Nb(V) and Nb(IV) complexes is quasi-reversible and is controlled predominantly by the diffusion.