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Title: Energetics of alkali and alkaline earth ion-exchanged zeolite A

Alkali and alkaline earth ion-exchanged zeolite A samples were synthesized in aqueous exchange media. They were thoroughly studied by powder X-ray diffraction (XRD), electron microprobe (EMPA), thermogravimetric analysis and differential scanning calorimetry (TG-DSC), and high temperature oxide melt solution calorimetry. The hydration energetics and enthalpies of formation of these zeolite A materials from constituent oxides were determined. Specifically, the hydration level of zeolite A has a linear dependence on the average ionic potential ( Z/r) of the cation, from 0.894 (Rb-A) to 1.317 per TO 2 (Mg-A). The formation enthalpies from oxides (25 °C) range from –93.71 ± 1.77 (K-A) to –48.02 ± 1.85 kJ/mol per TO 2 (Li-A) for hydrated alkali ion-exchanged zeolite A, and from –47.99 ± 1.20 (Ba-A) to –26.41 ± 1.71 kJ/mol per TO 2 (Mg-A) for hydrated alkaline earth ion-exchanged zeolite A. As a result, the formation enthalpy from oxides generally becomes less exothermic as Z/r increases, but a distinct difference in slope is observed between the alkali and the alkaline earth series.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. East China Univ. of Science and Technology, Shanghai (China); Univ. of California, Davis, CA (United States)
  2. Univ. of California, Davis, CA (United States); Washington State Univ., Pullman, WA (United States)
  3. East China Univ. of Science and Technology, Shanghai (China)
  4. Univ. of California, Davis, CA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  5. Univ. of California, Davis, CA (United States)
Publication Date:
Report Number(s):
LA-UR-16-23501
Journal ID: ISSN 1932-7447
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 120; Journal Issue: 28; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Inorganic and Physical Chemistry
OSTI Identifier:
1324571

Sun, Hui, Wu, Di, Liu, Kefeng, Guo, Xiaofeng, and Navrotsky, Alexandra. Energetics of alkali and alkaline earth ion-exchanged zeolite A. United States: N. p., Web. doi:10.1021/acs.jpcc.6b04840.
Sun, Hui, Wu, Di, Liu, Kefeng, Guo, Xiaofeng, & Navrotsky, Alexandra. Energetics of alkali and alkaline earth ion-exchanged zeolite A. United States. doi:10.1021/acs.jpcc.6b04840.
Sun, Hui, Wu, Di, Liu, Kefeng, Guo, Xiaofeng, and Navrotsky, Alexandra. 2016. "Energetics of alkali and alkaline earth ion-exchanged zeolite A". United States. doi:10.1021/acs.jpcc.6b04840. https://www.osti.gov/servlets/purl/1324571.
@article{osti_1324571,
title = {Energetics of alkali and alkaline earth ion-exchanged zeolite A},
author = {Sun, Hui and Wu, Di and Liu, Kefeng and Guo, Xiaofeng and Navrotsky, Alexandra},
abstractNote = {Alkali and alkaline earth ion-exchanged zeolite A samples were synthesized in aqueous exchange media. They were thoroughly studied by powder X-ray diffraction (XRD), electron microprobe (EMPA), thermogravimetric analysis and differential scanning calorimetry (TG-DSC), and high temperature oxide melt solution calorimetry. The hydration energetics and enthalpies of formation of these zeolite A materials from constituent oxides were determined. Specifically, the hydration level of zeolite A has a linear dependence on the average ionic potential (Z/r) of the cation, from 0.894 (Rb-A) to 1.317 per TO2 (Mg-A). The formation enthalpies from oxides (25 °C) range from –93.71 ± 1.77 (K-A) to –48.02 ± 1.85 kJ/mol per TO2 (Li-A) for hydrated alkali ion-exchanged zeolite A, and from –47.99 ± 1.20 (Ba-A) to –26.41 ± 1.71 kJ/mol per TO2 (Mg-A) for hydrated alkaline earth ion-exchanged zeolite A. As a result, the formation enthalpy from oxides generally becomes less exothermic as Z/r increases, but a distinct difference in slope is observed between the alkali and the alkaline earth series.},
doi = {10.1021/acs.jpcc.6b04840},
journal = {Journal of Physical Chemistry. C},
number = 28,
volume = 120,
place = {United States},
year = {2016},
month = {6}
}