Skip to Main content Skip to Navigation
Theses

Toolbox of post-synthetic mordenite modification strategies : Impact on textural, acidic, and catalytic properties

Abstract : Zeolites are extremely useful heterogeneous catalysts and find widespread industrial applications. Yet, their extended microporous system leads to rather low efficiency factors and favors the development of secondary reactions that can substantially reduce catalytic selectivity and stability. Hierarchization of zeolites has been proposed as strategy for efficiently reducing the diffusion path length, hence allowing to increase the efficiency factor in catalysis. Among the plethora of disclosed hierarchization strategies, the real impact of the structural and chemical modifications on the catalytic key parameters is oftentimes neglected. The aim of this contribution is thus to shed light on the effective quality of zeolite hierarchization through the rational study of structure/catalytic property dependency. Our study focused on mordenite, as this zeolite is of particular importance due to its strong acidity and monodimensional channel system, which explains why mordenite is industrially extensively employed in a variety of processes including alkylations, isomerizations, dehydrations and aminations. A toolbox of post-synthetic hierarchization strategies on aluminium rich and poor mordenites have been developed based on basic treatments assisted by CTAB and pyridine at various temperatures (in conventional and microwave heating) and acid HF etching in aqueous and organic medium. A systematic study of over 50 post-synthetically modified mordenites was conducted, which allowed us to assess the impact of each of the hierarchization strategy on textural, morphological, chemical and catalytic properties. Major correlations between structural features and catalytic activity, selectivity and stability in n-hexane cracking and toluene disproportionation were deduced. A roadmap on the quality of each hierarchization strategy was thus developed.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-02490785
Contributor : Abes Star :  Contact
Submitted on : Tuesday, February 25, 2020 - 2:59:09 PM
Last modification on : Monday, October 12, 2020 - 3:45:08 PM
Long-term archiving on: : Tuesday, May 26, 2020 - 5:26:18 PM

File

2019-Issa-Hussein-These.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02490785, version 1

Collections

Citation

Hussein Issa. Toolbox of post-synthetic mordenite modification strategies : Impact on textural, acidic, and catalytic properties. Chemical engineering. Université de Poitiers, 2019. English. ⟨NNT : 2019POIT2268⟩. ⟨tel-02490785⟩

Share

Metrics

Record views

114

Files downloads

151