title: Speciation, conductivities, diffusivities, and electrochemical reduction as a function of water content in mixtures of hydrated chromium chloride/choline chloride.
abstract: We report experiments and simulations to understand the factors that control chromium (Cr(3+)) electrodeposition from ionic liquid solutions. Speciation, conductivities and diffusivities in mixtures of trivalent chromium chloride, water and choline chloride (CrCl3/xH2O/yChCl) were computed from molecular dynamics simulations and compared to measured ultraviolet-visible spectra, conductivities from electrical impedance spectroscopy, and cyclic voltammograms. Computed changes in Cr(3+) first solvation shell and conductivity with solution composition qualitatively agree with experimental observations. The Cr(3+) first solvation shell contains predominantly H2O and Cl(-) and the proportion of the two ligands changes with the relative bulk concentrations of each. Conductivities and diffusivities are observed to be functions of these composition variables. Variations in observed reduction current are primarily determined by dynamical properties and are less influenced by speciation.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Dorrell C
authors.initials: DC
authors.lastname: McCalman
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Joan F
authors.initials: JF
authors.lastname: Brennecke
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Maginn
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: William F
authors.initials: WF
authors.lastname: Schneider