Rare earth elements, which include the lanthanide series, are ubiquitous and indispensable materials used in a wide range of technologies including smartphones, wind turbines, and electric vehicles. Due to the growth of these applications and challenges of the supply chain, new strategies for recycling and mining of lanthanides are an important and emerging goal, as stated by both the U.S. Department of Energy and the E.U. Commission. The difficulty in delivering pure lanthanides lies not only in the separation of lanthanides from ores, mining waste, or end-of-life products, but also in the separation of lanthanides from one another and is largely due to their similar physical and chemical properties. One preferred separation method is liquid-liquid extraction because of its simplicity, speed, and broad applicability. Traditionally, the successful separation of targeted lanthanides relied on a highly selective ligand in the organic phase to extract lanthanides from an aqueous solution. In this study, we investigate how an aqueous holdback agent, a pre-organized bis-lactam-1,10-phenanthroline derivative, can be leveraged for its affinity for light lanthanides, while diglycolamide-based ligands extract heavy lanthanides to the organic phase.

Use of bis-lactam-1,10-phenanthroline ligands as selective holdback reagents for for improved adjacent lanthanide separation

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.