Selective Adsorptive Recovery of Platinum from Spent Catalytic Converter

Abstract

Ethylene glycol dimethacrylate (EGDMA) – dithiadiamide (DTDA) copolymer was synthesized by condensation reaction between monomeric mercaptoacetamide and ?-dibromoalkanes. This previously designed DTDA was complexed with Pt²⁺ before direct copolymerization with EGDMA. Pt²⁺-template was eluted with dilute HCl. The EGDMA-DTDA copolymer was evaluated for Pt²⁺ adsorption in terms of adsorption isotherm and selectivity. The copolymer exhibited monolayer Langmuir-type adsorption isotherm with q_m = 177 mg g^-1 at optimum pH = 1. It is selective to Pt²⁺ in a simulated solution containing the predominant cations present in an acid-leached spent 3-way, gasoline automobile catalytic converter sample (i.e., Al³⁺, Ba²⁺, Ce³⁺, Fe²⁺, Mg²⁺, and Zn²⁺).