Evaluation of dithiadiamide-based molecular ion imprinted polymer (MIIP) for selective recovery of platinum from acid-digested spent automobile catalytic converter (ACC) solution

Platinum, being a critical raw material, needs to be recovered from secondary sources. Herein, Pt2+-selective adsorbents were synthesized from polymerizable dithiadiamide ligands via condensation reaction between mercaptoacetamide and w-dibromoalkanes with different alkane lengths. Molecular ion imprinted polymers (MIIP) were prepared by complexing and eluting Pt2+-template in dithiadiamide ligand-ethylene glycol dimethacrylate copolymers. MIIPs were systematically evaluated on its selective Pt2+ recovery through adsorption isotherm, kinetics, and recyclability. Selectivity tests were conducted using a simulated solution containing the predominant cations present in acid-leached spent 3-way, gasoline ACC sample and a Pt2+/Pd2+ binary solution. Data were corroborated with Density Functional Theory calculation.

Automated summary

This study focuses on the recovery of platinum and synthesizes adsorbents with Pt2+ selectivity. The performance of the adsorbents in selective recovery of Pt2+ was evaluated through adsorption isotherms, kinetics, and recyclability. The experimental results and calculation data confirm their selectivity.