Ion-exchange Extraction of Palladium(II) from Chloride Solutions Using a Silica Gel-Immobilized Imidazolium Salt

Silica Supported Ionic Liquids for the Efficient and Selective Recovery of Platinum and Palladium from Aqueous Media

“…5 N-donor or P-donor sites. 6,7 Lastly, non-covalent interactions can occur between ILs and anionic complexes of noble metals, such as Pt and Pd chlorocomplexes. Despite the potential of ILs in liquid−liquid extraction of metal species, there are also practical limitations displayed by some ILs, such as low diffusion coefficients, high viscosity, and difficulties in product purification and solvent recycling.…”

“…In this case, the metal species are mainly present as anionic complexes, which can be recovered by anion exchange with the IL . Furthermore, the IL cations can coordinate to noble metal atoms, such Pt and Pd, via orbital overlapping with N-donor or P-donor sites. , Lastly, non-covalent interactions can occur between ILs and anionic complexes of noble metals, such as Pt and Pd chlorocomplexes.…”

“…In addition, there is a decrease in the amount of required IL, as compared to conventional liquid–liquid separation, and, consequently, a reduction in the material’s price. The use of sorbents based on IL modified silica-gel materials for the recovery of Pt and Pd species in solution has only been reported in a few studies. ,,− For instance, Lanaridi et al reported the recovery of platinum group metals from a spent automotive catalyst using phosphonium-based ionic liquids. The authors prepared the SIL via physisorption of the ionic liquid on the silica support, and therefore, this material has low stability in the liquid phase with the possibility of leaching.…”

“…Similarly, Bui et al , prepared and applied solid supports impregnated with ammonium-, imidazolium-, and pyridinium-based ionic liquids for Pt­(IV) recovery from chloride solutions. Konshina et al demonstrated the ion-exchange extraction of Pd­(II) from chloride solutions using an imidazolium-based IL. Despite the high affinity of these materials for the removal of platinum and palladium, the authors used ILs with a long alkyl side chain, which may be more ecotoxic .…”

Efficient and selective adsorption of Au(iii), Pt(iv), and Pd(ii) by a radiation-crosslinked poly(ionic liquid) gel

“…13 In recent years, imidazole-based ILs have been widely used for surface modification and immobilization, and play an important role in adsorption separation and catalysis. [14][15][16][17][18][19] For example, Masilela et 6 ] and Cyphos 101 could also be used in the extraction of Ag(I). 20 Liu et al reported that 1-butyl-3-benzimidazole bromide ([HBBIm]Br) possessed a high extraction efficiency of 99.99% for Pt(IV) and Pd(II), and selectively extracted Pt(IV) and Pd(II).…”