Highly selective adsorption of Pt(IV) from spent catalyst by polyethyleneimine functionalized polyethylene/polypropylene non‐woven fabric

Aiming at efficient recovery of platinum (Pt) from aqueous solution, the aminated polyethylene/polypropylene non-woven fabric (PE/PP NWF) was synthesized via radiation grafting of glycidyl methacrylate (GMA), followed by ring-opening reaction with polyethyleneimine (PEI). The effects of different parameters, including pH, sorption time, initial Pt(IV) concentration, competing ions and adsorbent dosage on the Pt(IV) adsorption performance were investigated by batch adsorption tests. A high Pt(IV) adsorption capacity of 485.0 mg g−1 (initial concentration: 263.5 mg L−1) was achieved, and the adsorption kinetics and isotherm conformed to the pseudo-second-order model and the Langmuir isotherm model, respectively. Moreover, the PEI functionalized PE/PP NWF exhibited excellent adsorption performance over the wide pH range (1–6), and also good selectivity for Pt(IV) over multiple coexisting metal cations (Ni, Cu, Co, Pb, Mg, and Zn). The recovery ratio of Pt from spent proton exchange membrane fuel cell (PEMFC) catalysts reached 89.7% after three cycles of regeneration.