Liquid- and Solid-based Separations Employing Ionic Liquids for the Recovery of Platinum Group Metals Typically Encountered in Catalytic Converters: A Review

The wide application range and ascending demand for platinum group metals combined with the progressive depletion of their natural resources renders their efficient recycling a very important and pressing matter. Primarily environmental considerations associated with state-of-the-art recovery processes have shifted the focus of the scientific community toward the investigation of alternative recycling approaches. Within this context, ionic liquids have gained considerable attention in the last two decades chiefly sparked by properties such as tunabilty, low-volatility, and relatively easy recyclability. In this review an understanding of the state-of-the-art processes, including their drawbacks and limitations, is provided. The core of the discussion is focused on platinum group metal recovery with ionic liquid-based systems. A brief insight in some environmental considerations related to ionic liquids is also provided while some discussion on research gaps, common misconceptions related to ionic liquids and outlook on unresolved issues could not be absent from this review.

Automated summary

Efficient recycling of platinum group metals is of great importance due to their wide application range and increasing demand, as well as the depletion of natural resources. Ionic liquids have gained significant attention as alternative recycling approaches in the scientific community, thanks to their tunability, low volatility, and relatively easy recyclability. This review focuses on the state-of-the-art processes for platinum group metal recovery using ionic liquid-based systems, while also discussing environmental considerations, research gaps, common misconceptions, and unresolved issues.