Exploiting the coordination chemistry of high-valent americium for actinide/lanthanide separations

Efficient americium (Am)/lanthanide (Ln) separation is highly pursued in advanced nuclear fuel cycle for minimizing the long-term radiotoxicity of nuclear waste and maximizing the utilization of nuclear resources. However, such a task is extremely challenging given the chemical similarity between the inherent thermodynamically stable Am(III) and Ln(III) ions. In recent years, interest in Am/Ln separation through oxidizing Am(III) to higher-valent states is reigniting due to theoretically considerable separation efficiency of this approach. This review summarizes the developments in preparation and stabilization of high-valent Am, especially the progresses in the exploitation of the coordination chemistry of these high-valent Am for effective Am/Ln separation. This review aims to inspire the search for efficient redox and coordination systems with more robust Am/Ln separation performance. Efficient separation of americium from lanthanides is crucial for reducing nuclear waste radiotoxicity, yet highly challenging owing to the chemical similarities of Am(III) and Ln(III) ions. Here, the authors review advancements in the preparation and stabilization of higher-valent americium states, highlighting coordination chemistry strategies that enhance Am/Ln separation efficiencies.