Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures

doi:10.1021/acs.jpclett.9b02845

Title: Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl₂–KCl Mixtures

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Abstract

The development of technologies for nuclear reactors based on molten salts has seen a big resurgence. The success of thermodynamic models for these hinges in part on our ability to predict at the atomistic level the behavior of pure salts and their mixtures under a range of conditions. In this letter, we present high-energy X-ray scattering experiments and molecular dynamics simulations that describe the molten structure of mixtures of MgCl₂ and KCl. As one would expect, KCl is a prototypical salt in which structure is governed by simple charge alternation. In contrast, MgCl₂ and its mixtures with KCl display more complex correlations including intermediate-range order and the formation of Cl^–-decorated Mg²⁺ chains. A thorough computational analysis suggests that intermediate-range order beyond charge alternation may be traced to correlations between these chains. Here, an analysis of the coordination structure for Mg²⁺ ions paints a more complex picture than previously understood, with multiple accessible states of distinct geometries.

Authors:

Wu, Fei ^[1];

^[2];

^[2]; Gill, Simerjeet K. ^[3]; Topsakal, Mehmet ^[3]; Dooryhee, Eric ^[4]; Abeykoon, Milinda ^[4];

^[4];

^[5];

^[6]; Layne, Bobby ^[3];

^[7];

^[2];

^[1]

Univ. of Iowa, Iowa City, IA (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Brookhaven National Lab. (BNL), Upton, NY (United States)
Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
Argonne National Lab. (ANL), Argonne, IL (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Osaka Univ. (Japan)

Publication Date:: 2019-11-18

Research Org.:: Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II); Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Energy Frontier Research Centers (EFRC) (United States). Molten Salts in Extreme Environments (MSEE); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Nuclear Physics (NP); Japan Society for the Promotion of Science (JSPS)

OSTI Identifier:: 1593246

Alternate Identifier(s):: OSTI ID: 1593254; OSTI ID: 1605682; OSTI ID: 1606773

Report Number(s):: BNL-213564-2020-JAAM; BNL-213557-2020-JAAM
Journal ID: ISSN 1948-7185

Grant/Contract Number:: SC0012704; AC05-00OR22725; AC02-06CH11357; JP17J01006

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Physical Chemistry Letters

Additional Journal Information:: Journal Volume: 10; Journal Issue: 24; Journal ID: ISSN 1948-7185

Publisher:: American Chemical Society

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; KCl; MgCl2; Simulations; X-ray Scattering; molten chloride salts; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats


                    Wu, Fei, Roy, Santanu, Ivanov, Alexander S., Gill, Simerjeet K., Topsakal, Mehmet, Dooryhee, Eric, Abeykoon, Milinda, Kwon, Gihan, Gallington, Leighanne C., Halstenberg, Phillip, Layne, Bobby, Ishii, Yoshiki, Mahurin, Shannon M., Dai, Sheng, Bryantsev, Vyacheslav S., and Margulis, Claudio J. Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures.  United States: N. p., 2019. 
        Web.  doi:10.1021/acs.jpclett.9b02845.

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                    Wu, Fei, Roy, Santanu, Ivanov, Alexander S., Gill, Simerjeet K., Topsakal, Mehmet, Dooryhee, Eric, Abeykoon, Milinda, Kwon, Gihan, Gallington, Leighanne C., Halstenberg, Phillip, Layne, Bobby, Ishii, Yoshiki, Mahurin, Shannon M., Dai, Sheng, Bryantsev, Vyacheslav S., & Margulis, Claudio J. Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures.  United States.  doi:10.1021/acs.jpclett.9b02845.

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                    Wu, Fei, Roy, Santanu, Ivanov, Alexander S., Gill, Simerjeet K., Topsakal, Mehmet, Dooryhee, Eric, Abeykoon, Milinda, Kwon, Gihan, Gallington, Leighanne C., Halstenberg, Phillip, Layne, Bobby, Ishii, Yoshiki, Mahurin, Shannon M., Dai, Sheng, Bryantsev, Vyacheslav S., and Margulis, Claudio J. Mon .  
        "Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures".  United States.  doi:10.1021/acs.jpclett.9b02845.  https://www.osti.gov/servlets/purl/1593246.

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@article{osti_1593246,

  title        = {Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures},

  author       = {Wu, Fei and Roy, Santanu and Ivanov, Alexander S. and Gill, Simerjeet K. and Topsakal, Mehmet and Dooryhee, Eric and Abeykoon, Milinda and Kwon, Gihan and Gallington, Leighanne C. and Halstenberg, Phillip and Layne, Bobby and Ishii, Yoshiki and Mahurin, Shannon M. and Dai, Sheng and Bryantsev, Vyacheslav S. and Margulis, Claudio J.},

  abstractNote = {The development of technologies for nuclear reactors based on molten salts has seen a big resurgence. The success of thermodynamic models for these hinges in part on our ability to predict at the atomistic level the behavior of pure salts and their mixtures under a range of conditions. In this letter, we present high-energy X-ray scattering experiments and molecular dynamics simulations that describe the molten structure of mixtures of MgCl2 and KCl. As one would expect, KCl is a prototypical salt in which structure is governed by simple charge alternation. In contrast, MgCl2 and its mixtures with KCl display more complex correlations including intermediate-range order and the formation of Cl–-decorated Mg2+ chains. A thorough computational analysis suggests that intermediate-range order beyond charge alternation may be traced to correlations between these chains. Here, an analysis of the coordination structure for Mg2+ ions paints a more complex picture than previously understood, with multiple accessible states of distinct geometries.},

  doi          = {10.1021/acs.jpclett.9b02845},

  journal      = {Journal of Physical Chemistry Letters},

  number       = 24,

  volume       = 10,

  place        = {United States},

  year         = {2019},

  month        = {11}

}

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DOI: 10.1021/acs.jpclett.9b02845

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Title: Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures

Abstract

Citation Formats

Title: Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl₂–KCl Mixtures