Effect of Hydrophobicity of Ionic Liquids on the Leaching Selectivity of Platinum from a Spent Automotive Catalyst

Recycling platinum group metals from secondary resources such as spent automotive exhaust catalysts is promising for the circular economy. However, selective separation of Pt over massive amounts impurity Mg and Al particularly challenging. In this study, non-aqueous direct leaching a catalyst (SAC) using hydrophobic ionic liquids, namely, trihexyl(tetradecyl)phosphonium chloride (P66614Cl) trioctyl(dodecyl)phosphonium (P88812Cl) with aid pre-loading hydrochloric acid/hydrogen peroxide was proposed. The more P88812Cl exhibited efficient Al. recovery metal-loaded P88812Cl, reusability IL SAC were also demonstrated.