文献类型：期刊文献

英文题名：Energetics of Alkali and Alkaline Earth Ion-Exchanged Zeolite A

作者：Sun, Hui[1,2,3];Wu, Di[2,3,4];Liu, Kefeng[1];Guo, Xiaofeng[2,3,5];Navrotsky, Alexandra[2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Univ Calif Davis, Peter A Rock Thermochem Lab, One Shields Ave, Davis, CA 95616 USA;[3]Univ Calif Davis, NEAT ORU, One Shields Ave, Davis, CA 95616 USA;[4]Washington State Univ, Gene & Linda Voiland Sch Chem Engn & Bioengn, Pullman, WA 99163 USA;[5]Los Alamos Natl Lab, Div Earth & Environm Sci, Earth Syst Observat, Los Alamos, NM 87545 USA

年份：2016

卷号：120

期号：28

起止页码：15251

外文期刊名：JOURNAL OF PHYSICAL CHEMISTRY C

收录：;EI(收录号：20163102660447);WOS:【SCI-EXPANDED(收录号:WOS:000380590600029)】；

基金：This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Grant DE-FG02-05ER15667. H.S. thanks the Natural Science Foundation of Shanghai for the financial support (No. 16ZR1408100), and the China Scholarship Council for the State Scholarship Fund (No. 201308310077). D.W. acknowledges the institutional funds from the Gene and Linda Voiland School of Chemical Engineering and Bioengineering at Washington State University.

语种：英文

外文关键词：Differential scanning calorimetry - X ray diffraction - Thermogravimetric analysis - Enthalpy - Calorimeters - Ion exchange - Alkaline earth metals - Positive ions - Zeolites

摘要：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 degrees 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. 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.