DC Field | Value | Language |
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dc.contributor.advisor | Choi, Minkee | - |
dc.contributor.advisor | 최민기 | - |
dc.contributor.author | Eom, In Yong | - |
dc.date.accessioned | 2022-04-15T01:54:32Z | - |
dc.date.available | 2022-04-15T01:54:32Z | - |
dc.date.issued | 2021 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=956697&flag=dissertation | en_US |
dc.identifier.uri | http://hdl.handle.net/10203/294681 | - |
dc.description.abstract | Sn-BEA zeolite, a crystalline BEA-type stannosilicate, is one of the most important zeolite-based Lewis acid catalysts. Sn-BEA zeolite having Lewis acidic Sn (IV) centers within the hydrophobic zeolite framework that consists of mainly nonpolar Si–O–Si bonds is usually hydrothermally synthesized in a fluoride (F-) medium. Such hydrophobic Sn-BEA zeolites show high catalytic activities in various liquid-phase Lewis acid catalyzed reactions such as Baeyer-Villiger oxidation, Meerwein-Ponndorf-Verley reduction and Oppenauer oxidation, and glucose isomerization. However, conventional hydrothermal synthesis method for Sn-BEA zeolite requires considerable amount of hazardous chemicals such as F- and long zeolite crystallization time. In this respect, post-synthetic Sn-BEA zeolites via various post-synthetic methods have been intensively investigated. This study investigated the effects of structural properties of Sn-BEA zeolites, such as crystallite sizes, mesoporosity, and defect sites on catalytic activities for glucose isomerization both in water and 1-butanol over a series of Sn-BEA zeolites including one directly crystallized in a F- medium and the others prepared by the post-synthetic method developed in this study. The directly crystallized Sn-BEA showed high fructose yield (34%) in water because of its defect-free hydrophobic nature, which suppressed the inhibition of Lewis acid sites by water. However, in 1-butanol, it showed the lowest fructose yield and fastest deactivation among the catalysts, because of its extra-large zeolite crystallites (ca. 15 µm) causing mass transfer limitation and undesired side reactions. The Sn-BEA catalysts prepared by post-synthetic Sn incorporation showed limited catalytic performance in water because of hydroxyl defects. However, they showed superior performances in 1-butanol because of the much smaller crystallites and enhanced mass transfer. In particular, the hierarchical Sn-BEA having 10–20 nm crystallites and significant intercrystalline mesoporosity showed a very large fructose yield (55%) that are difficult to achieve in typical aqueous-phase glucose isomerization (<35%). The present work would provide important insight into the design of zeolite-based Lewis acid catalysts for biomass conversion. | - |
dc.language | eng | - |
dc.title | (The) effects of structural characteristics of Sn-BEA zeolites on catalytic activities for glucose Isomerization | - |
dc.title.alternative | Sn-BEA 제올라이트의 구조적 특성이 포도당 이성질화 반응에서 촉매 활성에 미치는 영향 | - |
dc.identifier.CNRN | 325007 | - |
dc.description.department | 한국과학기술원 :생명화학공학과, | - |
dc.description.isOpenAccess | 학위논문(박사) - 한국과학기술원 : 생명화학공학과, 2021.2,[v, 63 p. :] | - |
dc.publisher.country | 한국과학기술원 | - |
dc.type.journalArticle | Thesis(Ph.D) | - |
dc.contributor.alternativeauthor | 엄인용 | - |
dc.subject.keywordAuthor | Sn-BEA▼aLewis acid catalyst▼ahydrophobicity▼amesoporosity▼aglucose isomerization | - |
dc.subject.keywordAuthor | 틴 베타▼a루이스 산촉매▼a소수성▼a메조기공▼a포도당 이성질화 | - |
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