Nanosol precursor as structural promoter for clinoptilolite via hydrothermal synthesis and resulting effects on selective adsorption of CH4 and N2
Nanosol precursor as structural promoter for clinoptilolite via hydrothermal synthesis and resulting effects on selective adsorption of CH4 and N2
复制标题
纳米溶胶前体通过水热合成作为斜发沸石的结构促进剂及其对 CH4 和 N2 选择性吸附的影响
DOI：
10.1016/j.micromeso.2019.109913
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发表时间：
2020-03-01
影响因子：
5.2
通讯作者：
Bai, Shiyang
中科院分区：
文献类型：
--
作者：
Ouyang, Teng;Zhai, Chengwei;Bai, Shiyang
在423 K下通过6、60和102 h的水热预晶化时间得到纳米溶胶前驱体。在水热合成体系中加入不同量、不同晶化时间的纳米溶胶前驱体作为结构促进剂合成斜发沸石。采用XRD、SEM、BET、FT-IR、TG-DSC、ICP、UV-Raman和元素分析等手段对合成斜发沸石的结构和织构特征进行了表征，并探讨了斜发沸石在CH 4/N2-分离中的潜在应用。根据Arrhenius方程计算了斜发沸石在晶化过程中的诱导期活化能（E-n）和生长期活化能（E-g），前者远大于后者，证明成核是斜发沸石合成的关键。E-n值随SP加入量的增加和预晶化时间的延长而逐渐降低，进一步说明SP的加入和晶化时间的缩短有利于晶核的形成。然而，SP的量显着改变的粒度，杂质（钙钛矿）的程度，和斜发沸石的热稳定性。结果表明，在较低的温度下，可以在较短的时间内成功合成纯斜发沸石。特别是，添加剂SP（3 wt %）合成的斜发沸石在60 h的预晶化时间内的离子交换性能和CH 4/N2-分离能力与未添加SP的斜发沸石几乎相似，显示出很有前途的CH 4/N2-动力学分离吸附剂。
Nanosol precursor was obtained via hydrothermal pre-crystallization time periods of 6, 60 and 102 h at 423 K. Different amounts of nanosol precursor with different crystallization time periods were added to the hydrothermal synthesis system as structural promoter (SP) to synthesize clinoptilolite. The various characterizations such as XRD, SEM, BET, FT-IR, TG-DSC, ICP, UV-Raman, and element analysis were employed to investigate the structural and textural characteristics and potential applications of synthetic clinoptilolites in CH4/N-2 separation. Their activation energies of induction (E-n) and growth (E-g) periods during crystallization intervals were calculated according to Arrhenius equation, where the former being much larger than the latter proved that nucleation is the key in the synthesis of clinoptilolite. The E-n value gradually decreased with increasing amount of the SP and its pre-crystallization time interval, which further revealed that the addition of SP with the shortened crystallization time is beneficial in the formation of crystal nuclei. However, the amount of SP significantly altered the particle size, extent of impurities (phillipsite), and thermal stability of the clinoptilolite. The results demonstrated that pure clinoptilolite could be successfully synthesized in a short time period at low temperature. Particularly, the ion exchange performance and CH4/N-2 separation capacity of clinoptilolite synthesized with the additive SP (3 wt %) in the pre-crystallization interval of 60 h were found almost in similarity with the clinoptilolite prepared without SP, showing a promising adsorbent for kinetic separation of CH4/N-2.