Neptunium oxidation kinetics

T. W. Newton, The Kinetics of the Oxidation Reduction Reactions of Uranium, Neptunium, Plutonium, andMmericium inMqueous Solution, TlD-26506, U.S. Energy, Research, and Development Administration (ERDA) Technical Information Center, Washington, D.C., 1975. 

Tochiyama, O., Nakamura, Y., Hirota, M., Inoue, Y. 1995. Kinetics of nitrous acid-catalyzed oxidation of neptunium in nitric acid - TBP extraction system. J. Nucl. Sci. Technol. 32 118-124. 

Magnusson, L. B., J. C. Hindman, and T. J. LaChapelle Chemistry of Neptunium. Kinetics and Mechanism of Aqueous Oxidation-Reduction Reactions of Neptunium. In G. T. Seaborg, J. J. Katz, and W. M. Manning (Eds.) The Transuranium Elements, National Nuclear Energy Scries, Div. IV-14B, p. 1134. New York McGraw-Hill Co. 1949. 

COO/WOO] Cooper, J. N., Woods, M., Sullivan, J. C., Deutsch, E., Kinetics of the oxidation of selenium(lV) by neptunium(VlI) in aqueous acidic perchlorate media, Inorg. Chem., 15, (1976), 2862-2864. Cited on page 140. 

Oxidation of pentavalent neptunium by nitric acid. Oxidation of pentavalent neptunium to hexavalent by nitric acid requires catalysis by nitrous acid. The kinetics of this reaction have been studied by Siddall and Dukes [S16], Swanson [S24] and Mouline [M9]. Siddall and Dukes reported that the reaction was first order in neptunium concentration, independent of nitrous acid concentration if greater than 5 X 10" M, and depended on temperature T (K) and nitric acid molarity Xh as can be represented by Eq. (10.33) ... 

A kinetic study has been made of the oxidation of ascorbic acid (H A) by neptunium(vi). The rate law is of the form — d[NpVi]/dr=A 2[H2A] [Np i] with no evidence for a hydrogen-ion dependence over the range 0.05 < [H+] < l.OOM. In aqueous media Np i exists as the [O—Np—0] + ion with between four and six equatorial water molecules. A comparison with the reactions with aquo-ions, e.g. or where inner-sphere reactivity is established and with [Fe(phen)3] + indicates that the preferred pathway is outer sphere. The exchange rate for [(5-nitrophen)gFe] +/ + and the redox potential are both greater than for the Np VNp " couple and these features are considered- the reason for the rate of the present reaction being 40 times slower than that of the iron system. 

Actinides.— A kinetic study has been made of the reduction of neptunium(vn) and americium(vi) by bromide ion. In both cases two moles of oxidant are consumed in the production of a mole of Brj. The rate law governing the neptunium(vii) reduction is of the form... 

Newton, T. W. (1975) The Kinetics of Oxidation-Reduction Reactions of Uramum, Neptunium, Plutonium and Americium in Aqueous Solution, TID-26506. 

A kinetic investigation has been made of the oxidation of formic acid by neptunium(vn) in aqueous perchlorate solutions ... 

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