Optimization of separations of rare earths is essential for the growth and health of the US economy, since many rare earths play a critical role in advanced technology. There is a great need to optimize the separation methods to be highly selective, since separating contiguous lanthanides is particularly challenging. Through a collaborative experimental and theoretical project, we seek to explain trends observed experimentally in the separation of rare earths, as well as the changes of extraction preference of yttrium with respect to different extracting agents amongst the lanthanide series.The ultimate goal of our research is to enable knowledge-based design of separation agents, and in the short term to develop practical computational protocols with sufficient accuracy and robustness to be predictive yet sufficiently fast to be applied to many systems. A step-wise mechanism in the separation of lanthanides between solvent phases as a function of solvent and complexing agent will be presented with emphasis on acetylacetone, hexafluoroacetylacetone, 2-phenylbutyric acid, and acetic acid. The theoretical protocol involves an in-depth analysis of the step-wise reactions involved in a two-phased extraction method by considering different possible coordination environments. The thermodynamic and structural information obtained from computations present a unique contribution to separations chemistry.Harrison and Penchoff gratefully acknowledge the support of the National Science Foundation under grant OCI-0904972 �Computational chemistry and physics beyond the petascale.�

Theoretical studies of extracting agents for optimization of rare earth separations

248th National Meeting (2014)

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