Premium
Rapid Dissolution of Noble Metals in Organic Solvents
Author(s) -
Nag Abhijit,
Morrison Carole A.,
Love Jason B.
Publication year - 2022
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.202201285
Subject(s) - dissolution , chemistry , hydrogen peroxide , leaching (pedology) , chloride , inorganic chemistry , aqueous solution , solubility , reagent , metal , palladium , noble metal , oxalyl chloride , catalysis , platinum , organic chemistry , environmental science , soil science , soil water
The dissolution of elemental noble metals (NMs) such as gold, platinum, palladium, and copper is necessary for their recycling but carries a high environmental burden due to the use of strong acids and toxic reagents. Herein, a new approach was developed for the rapid dissolution of elemental NMs in organic solvents using mixtures of triphenylphosphine dichloride or oxalyl chloride and hydrogen peroxide, forming metal chloride salts directly. Almost quantitative dissolution of metallic Au, Pd, and Cu was observed within minutes at room temperature. For Pt, dissolution was achieved, albeit more slowly, using the chlorinating oxidant alone but was inhibited on addition of hydrogen peroxide. After leaching, transfer of Pt IV and Pd II chloride salts from the organic phase into a 6 m HCl aqueous phase facilitated their separation by precipitation of Pt IV using a simple diamide ligand. In contrast, the retention of Au III chloridometalate in the organic phase allowed its selective separation from Ni and Cu from a leachate solution obtained from electronic CPUs. This new approach has potential application in the hydrometallurgical leaching and purification of NMs from ores, spent catalysts, and electronic and nano‐wastes.