A Holistic Approach for Elucidating Local Structure, Dynamics, and Speciation in Molten Salts with High Structural Disorder.
Santanu RoyYang LiuMehmet TopsakalElaine DiasRuchi GakharWilliam C PhillipsJames F WishartDenis LeshchevPhillip HalstenbergSheng DaiSimerjeet K GillAnatoly I FrenkelVyacheslav S BryantsevPublished in: Journal of the American Chemical Society (2021)
To examine ion solvation, exchange, and speciation for minority components in molten salts (MS) typically found as corrosion products, we propose a multimodal approach combining extended X-ray absorption fine structure (EXAFS) spectroscopy, optical spectroscopy, ab initio molecular dynamics (AIMD) simulations, and rate theory of ion exchange. Going beyond conventional EXAFS analysis, our method can accurately quantify populations of different coordination states of ions with highly disordered coordination environments via linear combination fitting of the EXAFS spectra of these coordination states computed from AIMD to the experimental EXAFS spectrum. In a case study of dilute Ni(II) dissolved in the ZnCl2+KCl melts, our method reveals heterogeneous distributions of coordination states of Ni(II) that are sensitive to variations in temperature and melt composition. These results are fully explained by the difference in the chloride exchange dynamics at varied temperatures and melt compositions. This insight will enable a better understanding and control of ion solubility and transport in MS.
Keyphrases
- molecular dynamics
- high resolution
- density functional theory
- mass spectrometry
- ionic liquid
- multiple sclerosis
- ms ms
- organic matter
- single molecule
- air pollution
- quantum dots
- molecular dynamics simulations
- magnetic resonance imaging
- pain management
- solid state
- computed tomography
- metal organic framework
- chronic pain
- neural network