Hierarchically micro-meso-macroporous catalysts constructed from zeolite nanocrystals: Design, Synthesis and Application

Abstract

A series of novel hierarchically porous catalysts with significant micro-meso-macroporous structures constructed from zeolite nanocrystals have been successfully synthesized by a quasi solid state crystallization transformation process using a glycerin medium. These catalysts possess well-defined macropores and interconnected mesopores in the macropore walls which were constructed by selected microporous zeolitic units. A series of products, including hierarchically porous acidic aluminosilicates catalysts and hierarchically heteroatom-doped catalysts have been synthesized successfully by the quasi solid state crystallization transformation process. Hierarchical micro-meso-macroporous acidic catalysts constructed from zeolite ZSM-5 nanocrystals were synthesized using this synthetic system under the effect of a structure directing agent. The final product MMM-ZSM-5(2) presented an exceptional catalytic performance for the cracking of 1,3,5-triisopropylbenzene (TIPB). Hierarchically micro-meso-macroporous acidic catalysts constructed from zeolite Beta nanocrystals have also been synthesized. The acidity properties of the products formed after different crystallization transformation periods were investigated. Furthermore, hierarchically micro-meso-macroporous catalysts with heteroatom-doping into the zeolite architecture were also synthesized by this quasi solid state crystallization transformation process. Hierarchically micro-meso-macroporous catalysts constructed from crystalline titanium-doped silicalite-1(TS-1) were also obtained. The final product MMM-TS-1(3) presented superior catalytic performances both for the epoxidation of styrene and 2,4,6-trimethylstyrene. Finally, hierarchically micro-meso-macroporous catalysts constructed from zirconium-doped silicalite-1 (ZrS-1) nanocrystals were also synthesized successfully. The present work demonstrates that the quasi solid state crystallization transformation process is a facile and versatile method to synthesize micro-meso-macroporous catalysts with high performances in different reactions.

Date of Award	21 Jan 2011
Original language	French
Awarding Institution	University of Namur
Supervisor	BAO LIAN SU (Supervisor), Shilun QIU (Jury), Peter LODEWYCKX (Jury), Davide BONIFAZI (Jury), Alexandre Leonard (Jury) & Carmela Aprile (Jury)