Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5408857 | Journal of Molecular Liquids | 2017 | 37 Pages |
Abstract
Knowledge of the structure and speciation of aqueous Cu(II)-chloride complexes is important for understanding Cu(II) behavior in the deep removal technology of Cu impurity from nickel electrolysis anolytes containing chloride. In this paper, X-ray absorption spectroscopic measurements are reported for dissolved copper in lithium chloride (up to ~ 16 mol kgâ1) solutions at room temperature. The speciation and structure of corresponding solutions has been probed by performing a combined ab initio XANES theoretical and experimental analysis. The EXAFS spectrum was analyzed as well within this approach. Our XAS data and ab initio XANES calculations favored the five-coordinated [Cu(H2O)5]2+ with square pyramidal configuration over the four-(square planar and tetrahedron, [Cu(H2O)4]2+) and six-coordinated (octahedron, [Cu(H2O)6]2+) structure in dilute Clâ solution (~ 0.55 mol kgâ1). This is also supported by the EXAFS refinement with the [CuO5] model having the lowest statistical error. In the highest Clâ concentration solution, the results of both methods show that tetrahedral [CuCl4]2- complexes are predominant. Upon manually adjusting its geometric parameter to the distortion degree α of ~ 18° and average CuCl bond distance of 2.25 Ã
of a squashed tetrahedral model, not only does the calculated XANES spectrum well reproduce the experimental spectrum, but also the statistical error in the EXAFS refinements is lowest.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Ning Zhang, Wenlei Wang, Joël Brugger, Gui Zhang, Dewen Zeng,