Microcolumn lanthanide separation using bis-(2-ethylhexyl) phosphoric acid functionalized ordered mesoporous carbon...

Adjacent lanthanides are among the most challenging elements to separate, to the extent that current separations materials would benefit from transformative improvement. Ordered mesoporous carbon (OMC) materials are excellent candidates, owing to their small mesh size and uniform morphology. Herein, OMC materials were physisorbed with bis-(2-ethylhexyl) phosphoric acid (HDEHP) and sorption of Eu³⁺ was investigated under static and dynamic conditions. The HDEHP-OMC materials displayed higher distribution coefficients and loading capacities than current state-of-the-art materials. Using a small, unpressurized column, a separation between Eu³⁺ and Nd³⁺ was achieved. Based on these experimental results, HDEHP-OMC have shown potential as a solid phase sorbent for chromatographic, intragroup, lanthanide separations.