Benign recovery of platinum group metals from spent automotive catalysts using choline-based deep eutectic solvents

Sustainable and Selective Modern Methods of Noble Metal Recycling

“…Dissolution ability is heavily dependent on chloride concentration and the presence of toxic Cl 2 that can be in situ produced electrochemically or by chemical reaction. More expensive iodine‐iodide leaching shows similar efficiency to chlorine‐based dissolution but has not been yet successfully applied on pilot scale [32–35] . For now, recycling of PGMs is sufficiently following their excavation, but demand is expected to expansively grow in the future.…”

“…Their comparable chemistry in non‐aqueous media seems to play the vital role when selective dissolution is intended. Ionic liquids and deep eutectic solvents have been used as leaching systems to dissolve Pt, Pd and even more inert Rh [32, 33] . Trihalide ionic liquids [P 66614 ][Cl 3 ] can be even applied for preferential dissolution of Pd from multi‐metal substrate containing base metals, Pt and Rh (Figure 3c).…”

“…More expensive iodine-iodide leaching shows similar efficiency to chlorinebased dissolution but has not been yet successfully applied on pilot scale. [32][33][34][35] For now, recycling of PGMs is sufficiently following their excavation, but demand is expected to expansively grow in the future. New selective remediation techniques focusing on lowering the environmental impact are needed for their continuous and consistently expanding use.…”

“…Ionic liquids and deep eutectic solvents have been used as leaching systems to dissolve Pt, Pd and even more inert Rh. [32,33] Trihalide ionic liquids [P 66614 ][Cl 3 ] can be even applied for preferential dissolution of Pd from multi-metal substrate containing base metals, Pt and Rh (Figure 3c). [34] As well as ionic media, dissolution in common organic solvents like acetone, ethyl acetate, acetonitrile, THF and DCM offers an opportunity to efficiently dissolve Pd among other precious metals.…”

Investigation and mathematical correction of the matrix complexity effect on platinum group metals using inductively coupled plasma optical emission spectrometry determination

“…The spent automotive catalysts are typical secondary resources of PGMs, mainly containing Pd, Pt, and Rh, which are usually in the range of hundreds of g t −1 . 5,7 The enrichment of PGMs from spent automotive catalysts by pyrometallurgy is a short and efficient treatment process, and the main principle is using base metals to capture PGMs at high temperatures to form alloys. 8 The commonly used capture metals are Pb, Ni, Cu, and Fe.…”