Development of novel ionic liquids for the selective extraction of platinum group metals

Ueda, Yuki   ; Kikuchi, Kei

Platinum (Pt) and palladium are used for an exhaust gas catalysts, and the recycling of these metals are actively carried out with increasing the demand of Pt and Pd. There are few separating reagents that can separate PGM from each other, and development of a highly selective separating reagent is required. In this study, we synthesized the urea and thiourea substituted ionic liquids (IL) to achieve mutual separation of Pt(IV) and Pd(II) from the view point of IL can extract charged chemical species and can be functionalized by chemical modification. The urea and thiourea type of IL can selectively extract Pt(IV) and Pd(II) at lower pH region, respectively. Furthermore, spectroscopic analysis of the extraction mechanism revealed that Pt(IV) and Pd(II) were extracted by different extraction mechanisms.