Energetics of alkali and alkaline earth ion-exchanged zeolite A
- East China Univ. of Science and Technology, Shanghai (China); Univ. of California, Davis, CA (United States)
- Univ. of California, Davis, CA (United States); Washington State Univ., Pullman, WA (United States)
- East China Univ. of Science and Technology, Shanghai (China)
- Univ. of California, Davis, CA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Univ. of California, Davis, CA (United States)
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.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1324571
- Report Number(s):
- LA-UR-16-23501
- Journal Information:
- Journal of Physical Chemistry. C, Vol. 120, Issue 28; ISSN 1932-7447
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Thermodynamic evidence of flexibility in H 2 O and CO 2 absorption of transition metal ion exchanged zeolite LTA
|
journal | January 2018 |
Similar Records
Thermodynamics Drives the Stability of the MOF-74 Family in Water
Enthalpy of formation of rare-earth silicates Y{sub 2}SiO{sub 5} and Yb{sub 2}SiO{sub 5} and N-containing silicate Y{sub 10}(SiO{sub 4}){sub 6}N{sub 2}