{"title":"沸石 Beta 中以液体为媒介的缺陷修复处理研究","authors":"Finlay Clark , Raquel Garcia , Alessandro Turrina","doi":"10.1016/j.micromeso.2024.113177","DOIUrl":null,"url":null,"abstract":"<div><p>We report the application of a liquid-mediated defect-healing treatment based on tetraethylammonium (TEA<sup>+</sup>) hydroxide and ammonium fluoride, and variants thereof, to the H<sup>+</sup> form of zeolite beta. Through comparison between H-beta of high (730) and lower (28.6) SiO<sub>2</sub>: Al<sub>2</sub>O<sub>3</sub> ratios, and characterisation of the treated samples before and after calcination, insights into the interaction of TEA<sup>+</sup> and F<sup>−</sup> with H-beta under hydrothermal conditions were gained. In general, the treatments resulted in the loss of crystallinity and the generation of relatively large mesopores in the more siliceous samples, but improvements in long-range order and the development of relatively small mesopores in the less siliceous samples. The healing of silanol defects was observed for most of the treatments. A partial mechanism is proposed to explain the action of defect-healing treatments based on pore-occupying cations and F<sup>−</sup>; fluorine may be essential in some cases because it balances the charge of the organic cations, preventing the “trapping” of silanol groups as charge-balancing silanolate groups which resist healing.</p></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Investigation of a liquid-mediated defect-healing treatment in zeolite beta\",\"authors\":\"Finlay Clark , Raquel Garcia , Alessandro Turrina\",\"doi\":\"10.1016/j.micromeso.2024.113177\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We report the application of a liquid-mediated defect-healing treatment based on tetraethylammonium (TEA<sup>+</sup>) hydroxide and ammonium fluoride, and variants thereof, to the H<sup>+</sup> form of zeolite beta. Through comparison between H-beta of high (730) and lower (28.6) SiO<sub>2</sub>: Al<sub>2</sub>O<sub>3</sub> ratios, and characterisation of the treated samples before and after calcination, insights into the interaction of TEA<sup>+</sup> and F<sup>−</sup> with H-beta under hydrothermal conditions were gained. In general, the treatments resulted in the loss of crystallinity and the generation of relatively large mesopores in the more siliceous samples, but improvements in long-range order and the development of relatively small mesopores in the less siliceous samples. The healing of silanol defects was observed for most of the treatments. A partial mechanism is proposed to explain the action of defect-healing treatments based on pore-occupying cations and F<sup>−</sup>; fluorine may be essential in some cases because it balances the charge of the organic cations, preventing the “trapping” of silanol groups as charge-balancing silanolate groups which resist healing.</p></div>\",\"PeriodicalId\":392,\"journal\":{\"name\":\"Microporous and Mesoporous Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-05-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microporous and Mesoporous Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1387181124001999\",\"RegionNum\":3,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microporous and Mesoporous Materials","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1387181124001999","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
Investigation of a liquid-mediated defect-healing treatment in zeolite beta
We report the application of a liquid-mediated defect-healing treatment based on tetraethylammonium (TEA+) hydroxide and ammonium fluoride, and variants thereof, to the H+ form of zeolite beta. Through comparison between H-beta of high (730) and lower (28.6) SiO2: Al2O3 ratios, and characterisation of the treated samples before and after calcination, insights into the interaction of TEA+ and F− with H-beta under hydrothermal conditions were gained. In general, the treatments resulted in the loss of crystallinity and the generation of relatively large mesopores in the more siliceous samples, but improvements in long-range order and the development of relatively small mesopores in the less siliceous samples. The healing of silanol defects was observed for most of the treatments. A partial mechanism is proposed to explain the action of defect-healing treatments based on pore-occupying cations and F−; fluorine may be essential in some cases because it balances the charge of the organic cations, preventing the “trapping” of silanol groups as charge-balancing silanolate groups which resist healing.
期刊介绍：
Microporous and Mesoporous Materials covers novel and significant aspects of porous solids classified as either microporous (pore size up to 2 nm) or mesoporous (pore size 2 to 50 nm). The porosity should have a specific impact on the material properties or application. Typical examples are zeolites and zeolite-like materials, pillared materials, clathrasils and clathrates, carbon molecular sieves, ordered mesoporous materials, organic/inorganic porous hybrid materials, or porous metal oxides. Both natural and synthetic porous materials are within the scope of the journal.
Topics which are particularly of interest include:
All aspects of natural microporous and mesoporous solids
The synthesis of crystalline or amorphous porous materials
The physico-chemical characterization of microporous and mesoporous solids, especially spectroscopic and microscopic
The modification of microporous and mesoporous solids, for example by ion exchange or solid-state reactions
All topics related to diffusion of mobile species in the pores of microporous and mesoporous materials
Adsorption (and other separation techniques) using microporous or mesoporous adsorbents
Catalysis by microporous and mesoporous materials
Host/guest interactions
Theoretical chemistry and modelling of host/guest interactions
All topics related to the application of microporous and mesoporous materials in industrial catalysis, separation technology, environmental protection, electrochemistry, membranes, sensors, optical devices, etc.
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