DC Field | Value | Language |
---|---|---|
dc.contributor.author | Abraham, A | - |
dc.contributor.author | Lee, SH | - |
dc.contributor.author | Shin, CH | - |
dc.contributor.author | Hong, SB | - |
dc.contributor.author | Prins, R | - |
dc.contributor.author | van Bokhoven, JA | - |
dc.date.accessioned | 2015-06-25T02:55:28Z | - |
dc.date.available | 2015-06-25T02:55:28Z | - |
dc.date.created | 2009-12-18 | - |
dc.date.issued | 2004-06-07 | - |
dc.identifier.issn | 1463-9076 | - |
dc.identifier.other | 2015-OAK-0000019509 | en_US |
dc.identifier.uri | https://oasis.postech.ac.kr/handle/2014.oak/11888 | - |
dc.description.abstract | Al-27 magic-angle spinning (MAS) and triple quantum (3Q) MAS NMR spectroscopic techniques were used to characterise zeolite Beta samples with framework Si/Al ratios between 9 and 215, obtained by synthesis in fluoride medium. A carefully controlled stepwise calcination procedure was adopted to obtain H-Beta. A partial resolution of the T-sites was observed in the Al-27 MAS NMR spectra, the resolution increasing with increasing the Si/Al ratios. The relative intensity of these peaks varied gradually, with Si/Al ratio showing that the relative occupancy of the crystallographic T-sites changes with Si/Al ratio. The tetraethylammonium cation, used as an organic structure-directing agent in Beta synthesis, affects the average chemical shift of aluminium atoms in different T-sites. In H-Beta, octahedrally coordinated framework-associated aluminium atoms that could be quantitatively reverted into tetrahedral coordination were observed. The amount of this octahedral aluminium species decreases with increasing Si/Al ratio and it was absent for the two high-silica H-Beta samples with Si/Al = 110 and 215. Specific framework tetrahedral T-sites tend to convert to framework-associated octahedral sites during calcination It is suggested that two aluminium T-sites, which are adjacent or close to each other, obeying the Loewenstein's rule (i.e., no Al-O-Al linkage), are required for the hydrolysis of a Si-O-Al bond for the formation of octahedrally coordinated aluminium. The distribution of aluminium in zeolite Beta is a function of the Si/Al ratio and is non-uniformly distributed over the crystallographic T-sites. | - |
dc.description.statementofresponsibility | open | en_US |
dc.language | English | - |
dc.publisher | Royal Society of Chemistry | - |
dc.relation.isPartOf | PHYSICAL CHEMISTRY CHEMICAL PHYSICS | - |
dc.rights | BY_NC_ND | en_US |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/2.0/kr | en_US |
dc.title | Influence of Framework Silicon to Aluminum Ratio on Aluminum Distribution and Lewis Acidity in Zeolite Beta Investigated by 27Al MAS and MQ MAS NMR. | - |
dc.type | Article | - |
dc.contributor.college | 환경공학부 | en_US |
dc.identifier.doi | 10.1039/b401235f | - |
dc.author.google | Abraham, A | en_US |
dc.author.google | Lee, SH | en_US |
dc.author.google | van Bokhoven, JA | en_US |
dc.author.google | Prins, R | en_US |
dc.author.google | Hong, SB | en_US |
dc.author.google | Shin, CH | en_US |
dc.relation.volume | 6 | en_US |
dc.relation.issue | 11 | en_US |
dc.relation.startpage | 3031 | en_US |
dc.relation.lastpage | 3036 | en_US |
dc.contributor.id | 10077624 | en_US |
dc.relation.journal | PHYSICAL CHEMISTRY CHEMICAL PHYSICS | en_US |
dc.relation.index | SCI급, SCOPUS 등재논문 | en_US |
dc.relation.sci | SCI | en_US |
dc.collections.name | Journal Papers | en_US |
dc.type.rims | ART | - |
dc.identifier.bibliographicCitation | PHYSICAL CHEMISTRY CHEMICAL PHYSICS, v.6, no.11, pp.3031 - 3036 | - |
dc.identifier.wosid | 000222357600037 | - |
dc.date.tcdate | 2019-01-01 | - |
dc.citation.endPage | 3036 | - |
dc.citation.number | 11 | - |
dc.citation.startPage | 3031 | - |
dc.citation.title | PHYSICAL CHEMISTRY CHEMICAL PHYSICS | - |
dc.citation.volume | 6 | - |
dc.contributor.affiliatedAuthor | Hong, SB | - |
dc.description.journalClass | 1 | - |
dc.description.journalClass | 1 | - |
dc.description.wostc | 63 | - |
dc.type.docType | Article | - |
dc.subject.keywordPlus | ANGLE-SPINNING NMR | - |
dc.subject.keywordPlus | TETRAHEDRAL ALUMINUM | - |
dc.subject.keywordPlus | ALK-EDGE | - |
dc.subject.keywordPlus | SI-29 | - |
dc.subject.keywordPlus | SPECTRA | - |
dc.subject.keywordPlus | SITES | - |
dc.subject.keywordPlus | CONFIGURATION | - |
dc.subject.keywordPlus | ZSM-5 | - |
dc.relation.journalWebOfScienceCategory | Chemistry, Physical | - |
dc.relation.journalWebOfScienceCategory | Physics, Atomic, Molecular & Chemical | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
dc.relation.journalResearchArea | Chemistry | - |
dc.relation.journalResearchArea | Physics | - |
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