The recovery of platinum group metals (PGMs) from automotive exhaust catalysts is important, and hydrometallurgical extraction is an effective approach. In the present study, a newly designed phosphonium-based ionic liquid (IL) was applied to the separation and recovery of PGMs from an automobile catalyst leach liquor in conjunction with varying pH levels. This IL, trioctyldodecyl phosphonium chloride (P_8,8,8,12Cl), allows quantitative extraction of Pd(II) at any HCl concentration, with almost 80% removal of Rh(III) at 1 mol L^–1 HCl after two extractions. Significant amounts of Fe(III) were extracted into the IL phase, but could be removed using 1 mol L^–1 Na₂SO₃. The Pd(II) and Rh(III) were selectively recovered from the IL using 1 mol L^–1 CS(NH₂)₂ and 5 mol L^–1 HCl, respectively. This work therefore demonstrated the selective recovery of PGMs through optimization of various parameters and shows the significant potential of this IL with regard to recycling PGMs from leach liquor.

中文翻译：

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新型Ph基离子液体在汽车催化剂浸出液中分离铂族金属的应用

从汽车尾气催化剂中回收铂族金属（PGM）很重要，湿法冶金提取是一种有效的方法。在本研究中，结合不同的pH值，一种新设计的基于phospho的离子液体（IL）用于从汽车催化剂浸出液中分离和回收PGM。这种IL，三辛基_十二烷基氯化_nium（P _8,8,8,12 Cl），可以定量提取任何HCl浓度的Pd（II），两次分离后，以1 mol L ^–1 HCl去除近80％的Rh（III）。提取物。大量的Fe（III）被提取到IL相中，但可以使用1 mol L ^–1 Na ₂ SO ₃除去。。分别使用1 mol L ^–1 CS（NH ₂）₂和5 mol L ^–1 HCl从IL中选择性地回收Pd（II）和Rh（III）。因此，这项工作证明了通过优化各种参数选择性回收PGM的方法，并显示了该IL在从浸出液回收PGM方面的巨大潜力。