Desmoutier, Alec William;
(2025)
Investigation of Mesopore Formation in Zeolites Catalysis using QM/MM Methods.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Desmoutier_10207268_Thesis.pdf Download (5MB) | Preview |
Abstract
This thesis presents a comprehensive computational study on hydroxyl nest and mesopore formation in zeolitic frameworks through targeted T-site removals, utilizing hybrid quantum mechanics/molecular mechanics (QM/MM) calculations and density functional theory with def2-TZVP and def2-SVP basis sets. Zeolites ZSM-5, Chabazite, Faujasite, and α-Quartz were chosen for this investigation, offering a range of structural archetypes with varied channel systems and pore topologies. By selectively removing T-sites, we generated mesopores and analysed the stability, hydrogen-bonding networks, and structural changes within the framework to understand the energetics of mesopore generation. Our results indicate that the zeolites respond similarly to mesopore creation, with structural variations observed when comparing the adjacent and ring configurations. Mesopore formation is stabilized by three-membered silanol rings that form predictable and recurring hydrogen-bonded networks as T-sites are removed. Conversely, α-Quartz shows limited stable silanol ring formation, reflecting its more rigid crystalline structure leading to more hydrogen bonding between the silanols and the Si-O-Si oxygen atoms. Across all frameworks, the removal of additional T-sites beyond an optimal number was observed to introduce strain, and a less favourable energy for further pore expansion and occasionally leading to destabilized frameworks. The formation of Platinum nanoclusters are produced using Genetic Algorithms to produce results emulating ab initio techniques. These findings provide a new understanding of mesopore formation mechanisms in zeolitic structures and lay the groundwork for tailoring porous materials for catalytic applications.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Investigation of Mesopore Formation in Zeolites Catalysis using QM/MM Methods |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2025. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10207268 |
Archive Staff Only
 |
View Item |
