Evaluation of platinum extraction mechanism in ionic liquids using multinuclear NMR spectroscopy

• Extraction mechanism of platinum using BMIM-PF 6 ionic liquid is evaluated using 1 H, 19 F, 31 P, and 195 Pt NMR analysis. • The increase and decrease in 195 Pt and 19 F NMR signal for organic phase confirmed Pt extraction through anion exchange. • The 1 H NMR confirmed a change in the coordination around BMIM cation when Pt is extracted into the ionic liquid phase. • Increase in 19 F NMR signal for remaining aqueous phase, validated that Pt extraction takes place through anion exchange. Platinum group metals (PGMs), whose resources are limited, possess high economic value and are critical components in modern devices and appliances, making their recyclability essential. Ionic liquids (ILs) are safe and effective to recover and recycle PGMs from e-waste through different interaction mechanisms. This study evaluates the extraction mechanism of platinum (Pt) from aqueous media using the IL Butyl methyl imidazolium hexafluorophosphate (BMIM-PF 6 ) through multinuclear nuclear magnetic resonance (NMR) spectroscopy. The 195 Pt NMR spectra for the ionic liquid phase after Pt extraction show increased intensity with increasing platinum concentration, confirming the successful extraction of Pt into the ionic liquid. Additionally, increased signal intensity in the 19 F NMR spectra of the aqueous phase after extraction indicates that Pt extraction occurs via an anion exchange mechanism. Our results demonstrate that NMR spectroscopy is a powerful tool for elucidating metal ion extraction mechanisms.