Phosphorus-Based Polymers for Selective Capture of Platinum Group Metals

This work addresses the selective
recovery of platinum group metals
(PGMs) from aqueous streams, a critical issue within the recycling
and metal refining industries aiming to lose zero of the value contained.
Herein, selective PGM capture was investigated using three metal-capturing
polymeric resins from different manufacturers: a special anion exchanger
(Dow), an S-containing chelating resin (Lanxess), and a phosphine
oxide containing coordinating resin (Magpie Polymers). The relative
affinity of these different materials for the PGMs, as well as copper,
was compared under various conditions. It was found that the phosphine
oxide based material was the most suitable for the selective capture
of PGMs from an oxidizing solution containing high concentrations
of copper and counterions. Theoretical calculations using density
functional theory (DFT) have shown that the most likely binding of
PGMs to this material is a bidentate coordination via the phosphine
oxide groups.