Understanding Rare Earth Element Adsorption

RE complex formation schematic — Schematic representation of RE complex formation in RTIL [MMI][PF6].

Scientific Achievement

Theoretical exploration of solvation phenomena of bare rare-earth (RE) cations in room-temperature ionic-liquid (RTIL) to visualize the solvation mechanism of RE cations in RTIL at the molecular level.

Significance and Impact

Studying the extraction of RE cations using RTIL as extractant or diluant is important. By exploring the entire complexation phenomena between RTIL and RE cations, we examined whether the chosen RTIL prefers to bind with the light or heavy RE cations.

Research Details

First the structures and binding of incremental additions of PF6- to bare Nd(III) and Yb(III) was studied.
Complexation between RE cations and RTIL is studied in the gas and continuum solvation models employing RTIL parameters.
Structures, binding energy, and charge analyses all support preferential binding of [MMI][PF6] for Yb(III) over Nd(III).

Article Link: https://doi.org/10.1016/j.molliq.2023.123650