TWO DIMENSIONAL (2D) LEWIS ACIDIC ZEOLITE NANOSHEETS: SYNTHESIS, CHARACTERIZATION AND APPLICATIONS IN CATALYSIS AND SEPARATION

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dc.contributor.advisorLiu, Dongxiaen_US
dc.contributor.authorWu, Weien_US
dc.contributor.departmentChemical Engineeringen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2020-10-10T05:35:32Z
dc.date.available2020-10-10T05:35:32Z
dc.date.issued2020en_US
dc.description.abstractZeolites are generally defined as 3D crystalline microporous aluminosilicates, widely used for adsorption, separation, and acid catalysis in chemical and petrochemical industry. Except for aluminum, other elements, such as B, Ti and Sn, also can be incorporated into zeolite frameworks, bringing different Lewis acidities and conferring various chemical properties. Although the zeolites are eco-friendly industrial-scale catalysts, they are challenged in the catalytic processes involving bulky molecules. The inaccessibility of active sites confined in zeolite micropores and slow mass transport lead to inferior catalytic performances. In comparison to 3D zeolite, 2D zeolites, which are endowed intrinsic properties of micropores and enhanced mass transport as well as active site accessibility of mesopores, have gained enormous attention owing to their improved performance. This dissertation introduces several methods to prepare 2D zeolites and explores their applications in catalysis and separation. Firstly, we reported a low-cost method to prepare long-range ordering multilamellar titanium silicalite-1 (TS-1) zeolite. The pillarization on multilamellar TS-1 zeolite has been achieved to preserve the mesoporosity, while the influences of several synthesis parameters have been investigated to optimize the synthesis conditions. Afterwards, aiming to advance the understanding of Lewis acidity in these 2D TS-1 zeolites, we quantitatively described the concentration, strength and local environment of these Lewis acid sites, and evaluated their kinetic behaviors. Besides, a bottom-up method and a top-down method were introduced to prepare delaminated 2D zeolite nanosheets. With the assistance of a special-designed structure-directing agent, several heteroatom-containing 2D zeolite nanosheets have been directly synthesized. Their structural and textural properties have been evaluated by various techniques. In the top-down method, starting from multilamellar silicalite-1 (S-1) zeolites via exfoliation and separation steps, the delaminated S-1 zeolite nanosheets can be obtained and used to fabricate ultra-thin zeolite membrane applied in ethanol/water pervaporation. At last, we have created a series of novel ultra-thin film photocatalytic light absorbers (UFPLAs) to solve the long-standing trade-off between optical absorption and carrier transportation in photocatalyst. The UFPLAs have significantly boosted the activities in photocatalysis, in comparison to the benchmark Aeroxide®P25 catalyst, such as photocatalytic carbon dioxide reduction and photocatalytic chemical war agent simulant detoxification.en_US
dc.identifierhttps://doi.org/10.13016/kmzc-lahu
dc.identifier.urihttp://hdl.handle.net/1903/26609
dc.language.isoenen_US
dc.subject.pqcontrolledChemical engineeringen_US
dc.subject.pquncontrolled2D zeoliteen_US
dc.subject.pquncontrolledlamellar zeoliteen_US
dc.subject.pquncontrolledultra-thin film photocatalytic light absorberen_US
dc.subject.pquncontrolledzeolite acidityen_US
dc.subject.pquncontrolledzeolite membraneen_US
dc.titleTWO DIMENSIONAL (2D) LEWIS ACIDIC ZEOLITE NANOSHEETS: SYNTHESIS, CHARACTERIZATION AND APPLICATIONS IN CATALYSIS AND SEPARATIONen_US
dc.typeDissertationen_US

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