Solvent extraction in extended hydrogen bonded fluids – separation of Pt(iv) from Pd(ii) using TOPO-based type V DES

Abstract

In this work, the challenging solvent extraction (SX) separation of Pt(IV) from Pd(II) is investigated using non-ionic hydrophobic Type V deep eutectic solvent (DES) incorporating trioctylphosphine oxide (TOPO) as constituent....

Status and advances of deep eutectic solvents for metal separation and recovery

“…, pH, salinity, temperature, etc .). 113,159,173 Besides, the mechanical studies of the non-ionic type V DESs for metal extraction could be easier in the model systems. Take TOPO-based H(D)ESs for Pt( iv ) extraction as an example, TOPO: l-menthol, TOPO: 1-hexanol, and TOPO: 1-butanol were selected to investigate the interaction between H(D)ESs and PtCl 6 2− in a model system which was prepared by dissolving H 2 PtCl 6 in distilled water with hydrochloric acid.…”

“…Some typical type V DESs, including menthol-based, thymol-based and trioctylphosphine oxide (TOPO)-based DESs, were reported to be capable of selective metal extraction, such as In(III), Pt(IV), Pd(II), Fe(III), Cu(II) or Co(II), in the model systems of synthetic aqueous solutions. 86,90,113,159,173 For example, Schaeffer et al (2020) 86 reported that the TOPO-based DESs displayed good selectivity towards Pt 4+ , Pd 2+, and Fe 3+ over other transition metals (i.e., Cu 2+ , Co 2 + , Ni 2+ , and Cr 3+ ) in HCl aqueous solution; the selective separation of Pt(IV) from Pd(II) in HCl solutions could be also achieved by using the TOPO-based DESs extractants (i.e., TOPO : decanoic acid). 173 The extraction and separation of Cu(II) from other transition metals like Co(II) and Ni(II) could use the type V DESs based on menthol or its aromatic counterpart thymol combined with long-chain carboxylic acids.…”

“…86,90,113,159,173 For example, Schaeffer et al (2020) 86 reported that the TOPO-based DESs displayed good selectivity towards Pt 4+ , Pd 2+, and Fe 3+ over other transition metals (i.e., Cu 2+ , Co 2 + , Ni 2+ , and Cr 3+ ) in HCl aqueous solution; the selective separation of Pt(IV) from Pd(II) in HCl solutions could be also achieved by using the TOPO-based DESs extractants (i.e., TOPO : decanoic acid). 173 The extraction and separation of Cu(II) from other transition metals like Co(II) and Ni(II) could use the type V DESs based on menthol or its aromatic counterpart thymol combined with long-chain carboxylic acids. 113 It was shown that the selectivity of the metal extracted by type V DESs could be tuned by the selection of the DESs components, the mole fraction of the components, and the operating conditions during the solvent extraction process (e.g., pH, salinity, temperature, etc.).…”

“…113 It was shown that the selectivity of the metal extracted by type V DESs could be tuned by the selection of the DESs components, the mole fraction of the components, and the operating conditions during the solvent extraction process (e.g., pH, salinity, temperature, etc.). 113,159,173 Besides, the mechanical studies of the nonionic type V DESs for metal extraction could be easier in the model systems. Take TOPO-based H(D)ESs for Pt(IV) extraction as an example, TOPO: l-menthol, TOPO: 1-hexanol, and TOPO: 1-butanol were selected to investigate the interaction between H(D)ESs and PtCl 6…”

“…, TOPO : decanoic acid). 173 The extraction and separation of Cu( ii ) from other transition metals like Co( ii ) and Ni( ii ) could use the type V DESs based on menthol or its aromatic counterpart thymol combined with long-chain carboxylic acids. 113 It was shown that the selectivity of the metal extracted by type V DESs could be tuned by the selection of the DESs components, the mole fraction of the components, and the operating conditions during the solvent extraction process ( e.g.…”