caa a22 4500 378851306 CHVBK 20180305123324.0 cr unu---uuuuu 161128e20030901xx s 000 0 eng 10.1524/ract.91.9.499.19997 doi (NATIONALLICENCE)gruyter-10.1524/ract.91.9.499.19997 Heterogeneous catalytic oxidation of neptunium(IV) in nitric acid solutions [Elektronische Daten] [A. V. Ananiev, V.P. Shilov, Ph. Moisy, Charles Madic] Neptunium(IV), being quite stable in 0.5-3M HNO3, undergoes quick oxidation in the presence of 1 Pt/SiO2 catalyst. It was found that the catalytic oxidation of neptunium(IV) in nitric acid solutions proceeds even in the presence of anti-nitrous agent (such as NH2SO3H), though the rate of the reaction decreases to some extent. The kinetics of the heterogeneous catalytic oxidation of neptunium(IV) in nitric acid were studied for the following conditions: [HNO3] = 0.5-4.0M; [NH2SO3H] = 0 and 0.1M; T = 40–70°C; S/L = 0.025-0.1g/mL 1 Pt/SiO2. It was proposed that the mechanism of the neptunium(IV) oxidation is a result of the heterogeneous interaction of the Np(IV) aqua-ion with the nitronium ion NO2+ on the surface of the catalyst. The reaction deceleration and the increase of the apparent activation energy with the increase of the nitric acid concentration is explained by the complex formation of neptunium(IV) with nitrate ion. © 2003 Oldenbourg Wissenschaftsverlag GmbH Laboratory techniques, experiments nationallicence Analytical chemistry nationallicence Inorganic chemistry nationallicence Ananiev A. V. aut Shilov V.P. aut Moisy Ph aut Madic Charles aut Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 91/9/2003(2003-09-01), 499-504 0033-8230 91:9/2003<499 2003 91 ract https://doi.org/10.1524/ract.91.9.499.19997 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/ract.91.9.499.19997 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ananiev A. V. aut NATIONALLICENCE 700 1- Shilov V.P. aut NATIONALLICENCE 700 1- Moisy Ph aut NATIONALLICENCE 700 1- Madic Charles aut NATIONALLICENCE 773 0- Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 91/9/2003(2003-09-01), 499-504 0033-8230 91:9/2003<499 2003 91 ract CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter