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

Historic perspectives describing f-elements as being redox "inactive" are fading. Researchers continue to discover new oxidation states that are not as inaccessible as once assumed for actinides and lanthanides. Inspired by those contributions, we studied americium(III) oxidation in aqueous media under air using NaBiO 3( s ) . We identified selective oxidation of Am 3+ ( aq ) to AmO 2 2+ ( aq ) or AmO 2 1+ ( aq ) could be achieved by changing the aqueous matrix identity. AmO 2 2+ ( aq ) formed in H 3 PO 4( aq ) (1 M) and AmO 2 1+ ( aq ) formed in dilute HCl ( aq ) (0.1 M). These americyl products were stable for weeks in solution. Also included is a method to recover 243 Am from the americium and bismuth mixtures generated during these studies.