S. Kihara et al., A critical evaluation of the redox properties of uranium, neptunium and plutonium ions in acidic aqueous solutions - (Technical report), PUR A CHEM, 71(9), 1999, pp. 1771-1807
Standard redox potentials, E-s(o) and redox processes of U, Np and Pu ions
in acidic aqueous solutions are reviewed and evaluated critically. The E(o)
s of reversible redox processes, MO22+/MO2+ and M4+/M3+ (M: U, Np or Pu) ad
opted are those proposed mainly by Riglet es al. on the basis of the precis
e correction of formal potentials, E(o/)s, according to the improved theore
tical approach to estimate the activity coefficient. Electrode processes of
the U, Np and Pu ions are discussed in terms of current-potential curves,
measured so far by polarography, voltammetry or flow coulometry. Special at
tention is paid to the irreversible MO2+/ M4+ reactions. Disproportionation
reactions of MO2+ are also discussed. New substances are introduced as int
ermediates during reductions of MO2+ to M-4(+) or disproportionations of MO
2+.