TY - JOUR
T1 - Task-specific ionic liquid for solubilizing metal oxides
AU - Nockemann, Peter
AU - Thijs, B.
AU - Pittois, S.
AU - Thoen, J.
AU - Glorieux, C.
AU - Van Hecke, K.
AU - Van Meervelt, L.
AU - Kirchner, B.
AU - Binnemans, K.
PY - 2006/10/26
Y1 - 2006/10/26
N2 - Protonated betaine bis(trifluoromethylsulfonyl) imide is an ionic liquid with the ability to dissolve large quantities of metal oxides. This metal-solubilizing power is selective. Soluble are oxides of the trivalent rare earths, uranium(VI) oxide, zinc(II) oxide, cadmium( II) oxide, mercury( II) oxide, nickel( II) oxide, copper(II) oxide, palladium(II) oxide, lead(II) oxide, manganese( II) oxide, and silver( I) oxide. Insoluble or very poorly soluble are iron(III), manganese(IV), and cobalt oxides, as well as aluminum oxide and silicon dioxide. The metals can be stripped from the ionic liquid by treatment of the ionic liquid with an acidic aqueous solution. After transfer of the metal ions to the aqueous phase, the ionic liquid can be recycled for reuse. Betainium bis( trifluoromethylsulfonyl) imide forms one phase with water at high temperatures, whereas phase separation occurs below 55.5 degrees C ( temperature switch behavior). The mixtures of the ionic liquid with water also show a pH-dependent phase behavior: two phases occur at low pH, whereas one phase is present under neutral or alkaline conditions. The structures, the energetics, and the charge distribution of the betaine cation and the bis( trifluoromethylsulfonyl) imide anion, as well as the cation-anion pairs, were studied by density functional theory calculations.
AB - Protonated betaine bis(trifluoromethylsulfonyl) imide is an ionic liquid with the ability to dissolve large quantities of metal oxides. This metal-solubilizing power is selective. Soluble are oxides of the trivalent rare earths, uranium(VI) oxide, zinc(II) oxide, cadmium( II) oxide, mercury( II) oxide, nickel( II) oxide, copper(II) oxide, palladium(II) oxide, lead(II) oxide, manganese( II) oxide, and silver( I) oxide. Insoluble or very poorly soluble are iron(III), manganese(IV), and cobalt oxides, as well as aluminum oxide and silicon dioxide. The metals can be stripped from the ionic liquid by treatment of the ionic liquid with an acidic aqueous solution. After transfer of the metal ions to the aqueous phase, the ionic liquid can be recycled for reuse. Betainium bis( trifluoromethylsulfonyl) imide forms one phase with water at high temperatures, whereas phase separation occurs below 55.5 degrees C ( temperature switch behavior). The mixtures of the ionic liquid with water also show a pH-dependent phase behavior: two phases occur at low pH, whereas one phase is present under neutral or alkaline conditions. The structures, the energetics, and the charge distribution of the betaine cation and the bis( trifluoromethylsulfonyl) imide anion, as well as the cation-anion pairs, were studied by density functional theory calculations.
UR - http://www.scopus.com/inward/record.url?scp=33751265224&partnerID=8YFLogxK
U2 - 10.1021/jp0642995
DO - 10.1021/jp0642995
M3 - Article
SN - 1520-6106
VL - 110
SP - 20978
EP - 20992
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 42
ER -