Controllable growth of defect-free zeolite protective layer on the surface of Pd membrane for chemical stability enhancement
Controllable growth of defect-free zeolite protective layer on the surface of Pd membrane for chemical stability enhancement
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Pd膜表面无缺陷沸石保护层的可控生长以增强化学稳定性
DOI：
10.1016/j.micromeso.2017.02.063
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发表时间：
2017-05
影响因子：
5.2
通讯作者：
Xu Hengyong
中科院分区：
文献类型：
--
作者：
Yu Jiafeng;Zhang Jixin;Bao Chun;Zhang Zhe;Li Hui;Xu Hengyong
Pd膜具有良好的透氢性和选择性，在氢气净化中起着至关重要的作用。然而，Pd膜在接触包裹体气体或有机反应物时化学稳定性差，严重限制了其商业应用。本文提出了一种新的方法，即在Pd膜表面合成一层薄而致密的沸石层，作为保护Pd膜免受毒物破坏的“盔甲”。结果表明，当硅铝比为7.5，硅溶胶为硅源时，两步水热合成的沸石膜为NaA型，无缺陷。当Pd和沸石-Pd复合时，膜的氢渗透率的变化被监测。在氢气气氛中，将膜暴露在40%(乙醇/H2O)或0.2%四氢呋喃(THF)/10%N_2中。没有检测到乙醇和水在Pd活性中心上的反应，表明在沸石保护层的存在下，这些反应物与Pd膜完全脱离接触。特别是，与纯Pd膜相比，在350℃和W/E_6时，几乎80%的H_2膜的渗透率下降是由沸石的“盔甲”所限制的。此外，在沸石保护层的存在下，几乎80%的H_2膜的H_2透过率下降是由沸石“盔甲”限制的。沸石保护层通过抑制四氢呋喃的开裂和Pd活性中心的复盖，显著提高了Pd膜的化学稳定性。
Pd membranes play a critical role in hydrogen purification due to excellent hydrogen permeability and.selectivity. However, the poor chemical stability of Pd membranes when exposed to inclusion gases or.organic reactants severely restricts their commercial applications. Herein, a novel strategy is developed.to synthesize a thin and compact zeolite layer on the surface of Pd membrane which acts as an “armor” to.protect it from being damaged by poisoning species. The results show that the zeolite membrane was.NaA type and defect-free when using Si/Al ratio of 7.5 and silica sol as Si source after two-step hydrothermal.synthesis. The variations of H2 permeance is monitored when Pd and zeolite-Pd composite.membranes are exposed to 40% (ethanol/H2O) or 0.2% tetrahydrofuran (THF)/10% N2 in hydrogen atmosphere..Reactions between ethanol and water on Pd active sites are undetected, indicating the reactants.are completely out of contact with Pd membrane in the presence of zeolite protective layer..Especially, compared to pure Pd membrane, almost 80% H2 permeance decline is constrained by the.zeolite “armor” at 350 C and W/E ¼ 6. Moreover, the zeolite protective layer obviously enhances the.chemical stability of Pd membrane by suppressing THF cracking and Pd active sites coverage.
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影响因子：
29.4
作者：
Xiaoju Yin;Guangshan Zhu;Weishen Yang;Yanshuo Li;Guangqi Zhu;R. Xu;Jinyu Sun;Shilun Qiu;R. Xu
通讯作者：
Xiaoju Yin;Guangshan Zhu;Weishen Yang;Yanshuo Li;Guangqi Zhu;R. Xu;Jinyu Sun;Shilun Qiu;R. Xu
影响因子：
7.2
作者：
A. M. Silva;L. Mattos;J. Múnera;E. Lombardo;F. Noronha;L. Cornaglia
通讯作者：
A. M. Silva;L. Mattos;J. Múnera;E. Lombardo;F. Noronha;L. Cornaglia
影响因子：
5.2
作者：
J. Jansen;J. Koegler;H. Bekkum;H. Calis;C. M. Bleek;F. Kapteijn;J. Moulijn;E. Geus;N. V. D. Puil
通讯作者：
J. Jansen;J. Koegler;H. Bekkum;H. Calis;C. M. Bleek;F. Kapteijn;J. Moulijn;E. Geus;N. V. D. Puil
影响因子：
5.3
作者：
E. Mironova;M. Ermilova;N. Orekhova;D. Muraviev;A. Yaroslavtsev
通讯作者：
E. Mironova;M. Ermilova;N. Orekhova;D. Muraviev;A. Yaroslavtsev
影响因子：
2.8
作者：
M. A. Islam;S. Ilias
通讯作者：
M. A. Islam;S. Ilias