Mechanistic Insights into Reactive Zeolite-Water Interactions

• Název práce v češtině: Teoretické studium reaktivních interakcí vody se zeolity
• Název v anglickém jazyce: Mechanistic Insights into Reactive Zeolite-Water Interactions
• Klíčová slova: Teorie funkcionálu hustoty, katalýza, zeolity, molekulová dynamika, hydrolýza
• Klíčová slova anglicky: Density functional theory, catalysis, zeolites, molecular dynamics, hydrolysis
• Akademický rok vypsání: 2020/2021
• Typ práce: diplomová práce
• Jazyk práce: angličtina
• Ústav: Katedra fyzikální a makromol. chemie (31-260)
• Vedoucí / školitel: Christopher James Heard, Ph.D.
• Řešitel: skrytý - zadáno vedoucím/školitelem, čeká na schválení garantem
• Datum přihlášení: 15.11.2020
• Datum zadání: 15.11.2020
• Datum odevzdání elektronické podoby: 10.08.2022
• Datum proběhlé obhajoby: 12.09.2022
• Oponenti: Carlos Mauricio Maldonado Dominguez
• Konzultanti: prof. RNDr. Petr Nachtigall, Ph.D.

Zásady pro vypracování

Statistical thermodynamics and molecular simulation
Methods of molecular dynamics and Monte Carlo
Quantum chemistry

Seznam odborné literatury

(1) Heard, CJ; Grajciar, L .; Rice, CM; Pugh, SM; Nachtigall, P .; Ashbrook, SE; Morris, RE Fast Room Temperature Lability of Aluminosilicate Zeolites. Nat. Commun. 2019, 10, 4690.
(2) Bignami, GPM; Dawson, DM; Seymour, VR; Wheatley, PS; Morris, RE; Ashbrook, SE Synthesis, Isotopic Enrichment, and Solid-State NMR Characterization of Zeolites Derived from the Assembly, Disassembly, Organization, Reassembly Process. J. Am. Chem. Soc. 2017, 139, 5140–5148.
(3) Mizuno, N .; Mori, H .; Mineo, K .; Iwamoto, M. Isotopic Exchange of Oxygen between Proton-Exchanged Zeolites and Water. J. Phys. Chem. B 1999, 103, 10393–10399. (4) Pugh, SM; Wright, PA; Law, DJ; Thompson, N .; Ashbrook, SE Facile, Room-Temperature 17 O Enrichment of Zeolite Frameworks Revealed by Solid-State NMR Spectroscopy. J. Am. Chem. Soc. 2020, 142, 900–906.
(5) Millini, R .; Bellussi, G. Chapter 1. Zeolite Science and Perspectives. In Zeolites in Catalysis; Čejka, J., Morris, RE, Nachtigall, P., Eds .; The Royal Society of Chemistry: London, 2017; pp 1–26.
(6) Silaghi, MC; Chizallet, C .; Petracovschi, E .; Kerber, T .; Sauer, J .; Raybaud, P. Regioselectivity of Al-O Bond Hydrolysis during Zeolites Dealumination Unified by Brønsted-Evans-Polanyi Relationship. ACS Catal. 2015, 5, 11–15.
(7) Silaghi, MC; Chizallet, C .; Sauer, J .; Raybaud, P. Dealumination Mechanisms of Zeolites and Extra-Framework Aluminum Confinement. J. Catal. 2016, 339, 242–255.
(8) Ravenelle, RM; Schübler, F .; Damico, A .; Danilina, N .; Van Bokhoven, JA; Lercher, JA; Jones, CW; Sievers, C. Stability of Zeolites in Hot Liquid Water. J. Phys. Chem. OJ C 2010, 114, 19582–19595.
(9) Slavíček, P .; Muchova, E .; Hoolas, D .; Svoboda, V .; Svoboda, O. Kvantová Chemie, První vyd .; ICT: Prague, 2019.

Předběžná náplň práce

Research Motivation: Zeolite hydrolysis is a crucial part of many industrially important processes, including generation of controlled mesoporosity for hybrid porous silicate catalysts, and the stabilization of acid (aluminosilicate) catalysts in the petrochemical industry. While advances have been made recently in the mechanistic understanding of zeolite partial hydrolysis, there remain important questions regarding the selectivity of hydrolysis routes as a function of temperature, water loading in the micropores, and Si: Al ratio. Understanding these preferences requires a firmer grasp on the processes occurring at the atomic scale. Isotopic exchange of oxygen has become a popular tool for experimental analysis of the hydrolytic and healing routes in zeolites, which so far have not been rationalized in terms of reaction mechanisms inside the zeolite pore.
Research Outcomes: In this work, we will determine the energetics and mechanisms of both hydrolysis and oxygen exchange reactions under conditions which closely mimic experiments. The project will involve determining relevant mechanisms for a pristine (Q4Si) and partially hydrolyzed (Q3Si) zeolite with particular attention paid to routes towards framework healing via oxygen exchange. The model systems will be purely silicious chabazite (Si-CHA) and its aluminosilicate counterpart (Al-CHA). Temperature effects will also be investigated, in order to determine the importance of steaming "harshness" on the established mechanisms.
Methodologies: The project will primarily utilize advanced Ab Initio Molecular Dynamics simulations and biased free energy methods to explore, under realistic conditions, the energetic and mechanistic behaviour of a model zeolite (CHA) under hydration. In particular, thermodynamic integration will generate accurate free energy pathways along well-defined reaction coordinates, to hydrolysis and exchange pathways in zeolites. These methods will be coupled with static density functional calculations as guides to the reaction landscape, and open-ended metadynamics simulations, for the discovery of novel mechanisms and relevant low dimensional collective variables (reaction coordinates).
Teaching Outcomes: The project will require learning and mastery of various advanced computational methodologies: Density functional theory (plane wave), structure optimization, transition state calculations (transition state theory), molecular dynamics (Ab Initio), biased dynamics (Slow growth and thermodynamic integration), metadynamics (Ab Initio). The project will also involve overlap between theory and experiment. Knowledge will be required of various experimental analysis techniques, especially MAS-NMR and FTIR. The student will collaborate within a computational group, and gain experience in presenting data orally and in written form, and scientific writing (in particular articles for publication).

Předběžná náplň práce v anglickém jazyce

Research Motivation: Zeolite hydrolysis is a crucial part of many industrially important processes, including generation of controlled mesoporosity for hybrid porous silicate catalysts, and the stabilization of acid (aluminosilicate) catalysts in the petrochemical industry. While advances have been made recently in the mechanistic understanding of zeolite partial hydrolysis, there remain important questions regarding the selectivity of hydrolysis routes as a function of temperature, water loading in the micropores, and Si: Al ratio. Understanding these preferences requires a firmer grasp on the processes occurring at the atomic scale. Isotopic exchange of oxygen has become a popular tool for experimental analysis of the hydrolytic and healing routes in zeolites, which so far have not been rationalized in terms of reaction mechanisms inside the zeolite pore.
Research Outcomes: In this work, we will determine the energetics and mechanisms of both hydrolysis and oxygen exchange reactions under conditions which closely mimic experiments. The project will involve determining relevant mechanisms for a pristine (Q4Si) and partially hydrolyzed (Q3Si) zeolite with particular attention paid to routes towards framework healing via oxygen exchange. The model systems will be purely silicious chabazite (Si-CHA) and its aluminosilicate counterpart (Al-CHA). Temperature effects will also be investigated, in order to determine the importance of steaming "harshness" on the established mechanisms.
Methodologies: The project will primarily utilize advanced Ab Initio Molecular Dynamics simulations and biased free energy methods to explore, under realistic conditions, the energetic and mechanistic behaviour of a model zeolite (CHA) under hydration. In particular, thermodynamic integration will generate accurate free energy pathways along well-defined reaction coordinates, to hydrolysis and exchange pathways in zeolites. These methods will be coupled with static density functional calculations as guides to the reaction landscape, and open-ended metadynamics simulations, for the discovery of novel mechanisms and relevant low dimensional collective variables (reaction coordinates).
Teaching Outcomes: The project will require learning and mastery of various advanced computational methodologies: Density functional theory (plane wave), structure optimization, transition state calculations (transition state theory), molecular dynamics (Ab Initio), biased dynamics (Slow growth and thermodynamic integration), metadynamics (Ab Initio). The project will also involve overlap between theory and experiment. Knowledge will be required of various experimental analysis techniques, especially MAS-NMR and FTIR. The student will collaborate within a computational group, and gain experience in presenting data orally and in written form, and scientific writing (in particular articles for publication).