A Novel Metastable Pentavalent Plutonium Solid Phase on the Pathway from Aqueous Plutonium(VI) to PuO2 Nanoparticles.

Kristina O Kvashnina,Alexander Trigub,Sergei M Butorin,Andreas C Scheinost,Anna Yu Romanchuk,Ivan Pidchenko,Stephan Weiss,Stepan N Kalmykov,Olaf Walter,Andre Rossberg,Evgeny Gerber,Roberto Caciuffo,Lucia Amidani,Karin Popa

doi:10.1002/anie.201911637

Abstract

Here we provide evidence that the formation of PuO2 nanoparticles from oxidized PuVI under alkaline conditions proceeds through the formation of an intermediate PuV solid phase, similar to NH4PuO2CO3, which is stable over a period of several months. For the first time, state‐of‐the‐art experiments at Pu M4 and at L3 absorption edges combined with theoretical calculations unambiguously allow to determine the oxidation state and the local structure of this intermediate phase.

Highlights

We provide evidence that the formation of PuO2 nanoparticles from oxidized PuVI under alkaline conditions proceeds through the formation of an intermediate PuV solid phase, similar to NH4PuO2CO3, which is stable over a period of several months
Plutonium plays a prominent role in nuclear energy production but nuclear accidents and nuclear weapons tests have led to the release of Pu and other hazardous isotopes into the environment in the past, and Pu contamination has been detected in waters and soils.[1]
The oxidation state is defined by the number of electrons that are removed from the valence orbitals of a neutral atom

Summary

Introduction

We provide evidence that the formation of PuO2 nanoparticles from oxidized PuVI under alkaline conditions proceeds through the formation of an intermediate PuV solid phase, similar to NH4PuO2CO3, which is stable over a period of several months. We have previously shown that HERFD experiments at the U M4 edge[18,19,20] are much more informative on the oxidation state and electronic structure than measurements at the L

Results

Conclusion