Analytical Oxidation of Americium with Sodium Perxenate.

Abstract

Sir: I wish to report a successful application of sodium perxenate, Na4-Xe06, to the analytical oxidation of Am(III) to Am(VI). This work may be the first report of a practical use of this compound.Since the first discoveries that xenon would react with other elements (ß, 8), much research effort has been put forth in this new field of the noble gas compounds.One of these compounds, sodium perxenate, appears to be potentially useful as an analytical reagent.Sodium perxenate was first prepared by Malm, Holt, and Bane (5), who found the compound to be a stable solid under ordinary conditions. Later studies by Appelman and Malm (1) revealed that the compound had a high oxidation potential of about 3 volts in acidic solutions. However, they also found that the reaction Xe(VIII) -*•

Higher Oxidation States of Americium: Preparation, Characterization and Use for Separations

“…The Xe(VIII)-containing sodium perxenate, Na 4 XeO 6 , has an oxidation potential of about 3 V and has been used to prepare Am(VI) in dilute nitric acid. Holcomb found that the addition of silver improved the yields most likely because of the capacity of silver ions to maintain Am(VI) after its oxidation by Xe(VIII) . This effect was also observed by Hara when (NH 3 ) 2 S 2 O 8 and silver ion were used to oxidize americium to Am(VI) in dilute nitric acid…”

“…Holcomb found that the addition of silver improved the yields most likely because of the capacity of silver ions to maintain Am(VI) after its oxidation by Xe(VIII). 22 This effect was also observed by Hara when (NH 3 ) 2 S 2 O 8 and silver ion were used to oxidize americium to Am(VI) in dilute nitric acid. 68 Tsushima and co-workers oxidized americium photochemically in 0.02À0.2 M HNO 3 by using a deuterium lamp.…”

Oxidizing Americium(III) with Sodium Bismuthate in Acidic Aqueous Solutions

“…Some highlights from these developments include discovering actinides and lanthanides in unusually low and high oxidation states, using redox active ligands to achieve multi-electron transfer chemistry from redox inactive metals, and the isolation of molecules containing terbium­(IV) and praseodymium­(IV). − High oxidation state americium chemistry represents another growth area. Oxidizing americium has been realized using various techniques (electrochemical, − photochemical, , and solid-state synthesis). − Oxidizing americium can also occur in aqueous solutions under air using powerful oxidants, e.g., NaBiO 3 , − Cu­(IO 4 ) 2 , O 3 , , a variety of Xe 8+ reagents, and others . However, the Am 3+ ( aq ) oxidation reaction is not synthetically straightforward.…”

Photocatalytic Conversion of Am(III) to Am(VI) Using a TiO2 Electrode

“…6 A variety of chemical oxidants have been developed for Am(III) oxidation, 7 including persulfate, 8 sodium bismuthate, 9,10 copper periodate, 11 silver ions in conjunction with ozone, 12 even noble gas compounds. 13 From a fuel cycle prospective, many of these oxidants have drawbacks due to downstream complications such as in the case of persulfate, where the sulfate product inhibits vitrification of the waste, or engineering complications as in the design of a filtration step to remove insoluble sodium bismuthate. Excess molar equivalents must be added to generate and maintain Am(VI), and the addition of chemical oxidants increases the waste volume.…”

“…Am­(VI) is difficult to generate given the high Am­(IV/III) couple ( E 1/2 = 2.62 V vs SHE) . A variety of chemical oxidants have been developed for Am­(III) oxidation, including persulfate, sodium bismuthate, , copper periodate, silver ions in conjunction with ozone, even noble gas compounds . From a fuel cycle prospective, many of these oxidants have drawbacks due to downstream complications such as in the case of persulfate, where the sulfate product inhibits vitrification of the waste, or engineering complications as in the design of a filtration step to remove insoluble sodium bismuthate.…”