Gp. Nikitina et al., Oxidation of variable-valence cations with ozone: II. Selection of a cation catalyzing oxidative dissolution of plutonium oxide, RADIOCHEMIS, 41(6), 1999, pp. 538-544
Main features of reactions of variable-valence cations Mn+ [Mn+ = Ag(I), Ru
(IV), Ce(III), TI(I), Np(IV, V), Pu(IV)] with ozone in nitric acid solution
s were studied. The kinetic parameters of reaction of Np(IV) and Pu(IV) wit
h O-3 in a wide range of reaction conditions were determined. The mechanism
of intraspheric oxidation involving formation of outerspheric complex of t
he ion being oxidized with ozone (Mn+ <--OH2... O-3) with subsequent substi
tution of intraspheric water molecule with ozone or detachment of the hydro
gen atom from the hydrate water molecule to form Mn+<--OH and HO3 was propo
sed. Plutonium(IV) is most likely to be oxidized with ozone via formation o
f Pu4+<--O-3 complex. Ag(I), Ce(III), and Co(II) were chosen as catalysts o
f dissolution of PuO2 by its oxidation with ozone.