Selective extraction of Pd(II) with a thiourea-introduced ionic liquid

Kikuchi, Kei; Ueda, Yuki   

The production sites of the palladium (Pd) primary resources are located specific areas and its amount are limited. The social demands for Pd have been increased with increasing the social demand for fuel cells because Pd has an excellent hydrogen storage capacity. Therefore, the development of the novel separating reagents for Pd is required. In this study, the novel thiourea-introduced ionic liquid was synthesized and its extraction ability of Pd was evaluated from a viewpoint the effective recovery of Pd. Ionic liquids (ILs) are salts with the melting points below 373 K. ILs have attracted substantial interest as a green alternative solvent due to their non-volatile and non-flammable properties. From the Pd extraction study, the novel IL has highly Pd extraction ability from relatively high acidic solutions. Slope analysis and extended X-ray absorption fine structure spectroscopy of the extracted complex of Pd was carried out to determine the detail extraction mechanism.