A5020312426- Zeolite Catalysis and Synthesis
- Catalysis and Oxidation Reactions
- Catalysis and Hydrodesulfurization Studies
- Catalytic Processes in Materials Science
- Metal-Organic Frameworks: Synthesis and Applications
- Mesoporous Materials and Catalysis
- Advanced Chemical Physics Studies
- Catalysis for Biomass Conversion
- Advanced NMR Techniques and Applications
- Polyoxometalates: Synthesis and Applications
- Chemical Synthesis and Characterization
- Machine Learning in Materials Science
- Ammonia Synthesis and Nitrogen Reduction
- Carbon dioxide utilization in catalysis
- Crystal Structures and Properties
- Spectroscopy and Quantum Chemical Studies
- Surface Chemistry and Catalysis
- Platelet Disorders and Treatments
- Innovative Microfluidic and Catalytic Techniques Innovation
- Chemical Synthesis and Analysis
- Magnetism in coordination complexes
- Geochemistry and Geologic Mapping
- Catalysts for Methane Reforming
- Paleontology and Stratigraphy of Fossils
- Blood groups and transfusion
VIB-KU Leuven Center for Cancer Biology
2025
KU Leuven
2023
Ghent University
2012-2022
Ghent University Hospital
2016-2019
Vitenparken
2019
Stanford University
2018
SLAC National Accelerator Laboratory
2018
Interface (United States)
2018
Institute for Atomic and Molecular Physics
2015-2016
University of Amsterdam
2015-2016
Abstract The conversion of methanol to olefins (MTO) over a heterogeneous nanoporous catalyst material is highly complex process involving cascade elementary reactions. elucidation the reaction mechanisms leading either desired production ethene and/or propene or undesired deactivation has challenged researchers for many decades. Clearly, choice, in particular topology and acidity, as well specific conditions determine overall MTO activity selectivity; however, subtle balances between these...
The direct transformation of CO2 into high-value-added hydrocarbons (i.e., olefins and aromatics) has the potential to make a decisive impact in our society. However, despite efforts scientific community, no synthetic route exists today synthesize aromatics from with high productivities low undesired CO selectivity. Herein, we report combination series catalysts comprising potassium superoxide doped iron oxide highly acidic zeolite (ZSM-5 MOR) that directly convert either light (in or ZSM-5)...
The role of water in the methanol-to-olefins (MTO) process over H-SAPO-34 has been elucidated by a combined theoretical and experimental approach, encompassing advanced molecular dynamics simulations situ microspectroscopy. First-principles calculations at level point out that competes with methanol propene for direct access to Brønsted acid sites. This results less efficient activation these molecules, which are crucial formation hydrocarbon pool. Furthermore, lower intrinsic reactivity...
The catalytic conversion of methanol (MeOH) and dimethyl ether (DME) into fuels chemicals over zeolites (MTH process) is industrially emerging as an alternative route to conventional oil-derived processes. After 40 years research, a detailed mechanistic understanding the intricate reaction network still not fully accomplished. overall described two competitive cycles, dominated by alkenes arenes, which are methylated cracked or dealkylated form effluent products. Herein, we present isobutene...
Catalytic cracking of alkenes takes place at elevated temperatures in the order 773–833 K. In this work, nature reactive intermediates typical reaction conditions is studied H-ZSM-5 using a complementary set modeling tools. Ab initio static and molecular dynamics simulations are performed on different C4 C5 alkene to identify species terms temperature. At 323 K, prevalent linear alkoxides, π-complexes tertiary carbenium ions. temperature 773 however, both secondary alkoxides unlikely exist...
A systematic molecular level and spectroscopic investigation is presented to show the cooperative role of Brønsted acid Lewis sites in zeolites for conversion methanol. Extra-framework alkaline-earth metal containing species aluminum decrease number sites, as protonated clusters are formed. combined experimental theoretical effort shows that postsynthetically modified ZSM-5 zeolites, by incorporation extra-framework metals or demetalation with dealuminating agents, contain both mononuclear...
Catalytic alkene cracking on H-ZSM-5 involves a complex reaction network with many possible routes and often elusive intermediates. Herein, advanced molecular dynamics simulations at 773 K, typical temperature, are performed to clarify the nature of intermediates elucidate dominant pathways operating conditions. A series C4-C8 investigated evaluate influence chain length degree branching their stability. Our reveal that linear, secondary carbenium ions relatively unstable, although lifetime...
The methylation of arenes is a key step in the production hydrocarbons from methanol over acidic zeolites. We performed ab initio static and molecular dynamics free energy simulations benzene H-ZSM-5 to determine factors that influence reaction kinetics. Special emphasis given effect surrounding molecules on It found for higher loadings, may also occur protonated cluster, indicating exact location Brønsted acid site not essential zeolite-catalyzed reaction. However, methylations cluster...
Abstract The formation and nature of active sites for methanol conversion over solid acid catalyst materials are studied by using a unique combined spectroscopic theoretical approach. A working the methanol‐to‐olefin has hybrid organic–inorganic in which cocatalytic organic species is trapped zeolite pores. As case study, microporous with chabazite topology, namely, H‐SAPO‐34 H‐SSZ‐13, considered (poly)aromatic species. First‐principle rate calculations on methylation reactions situ UV/Vis...
Abstract Incorporation of Ca in ZSM‐5 results a twofold increase propylene selectivity (53 %), total light‐olefin 90 %, and nine times longer catalyst lifetime (throughput 792 g MeOH −1 ) the methanol‐to‐olefins (MTO) reaction. Analysis product distribution theoretical calculations reveal that post‐synthetic modification with 2+ leads to formation CaOCaOH + strongly weaken acid strength zeolite. As result, rate hydride transfer oligomerization reactions on these sites is greatly reduced,...
The diffusion of olefins through 8-ring solid acid microporous zeolites is investigated using molecular dynamics simulations techniques and a newly developed flexible force field. Within the context methanol-to-olefin (MTO) process observed product distribution, knowledge paths essential to obtain level control over conditions. Eight-ring zeotype materials are favorably used for MTO as they give selective distribution toward low-carbon olefins. To investigate how composition, acidity,...
The optical absorption properties of (poly)aromatic hydrocarbons occluded in a nanoporous environment were investigated by theoretical and experimental methods. carbonaceous species are an essential part working catalyst for the methanol-to-olefins (MTO) process. In situ UV/Vis microscopy measurements on methanol conversion over acidic solid catalysts H-SAPO-34 H-SSZ-13 revealed growth various broad bands around 400, 480, 580 nm. cationic nature involved was determined interaction ammonia...
Abstract Framework‐bound methoxides occur as intermediates in the stepwise mechanism for zeolite‐catalyzed methylation reactions. Herein, formation of from methanol or dimethyl ether H‐ZSM‐5 is investigated by a combination static and dynamic simulations, with particular focus on effect additional water molecules kinetics. Metadynamics simulations allow partitioning reaction path into distinct phases. Proton transfer zeolite to reactants found be rate‐limiting phase methoxide formation....
The active site in ethene oligomerization catalyzed by Ni-zeolites is proposed to be a mobile Ni(II) complex, based on density functional theory-based molecular dynamics (DFT-MD) simulations corroborated continuous-flow experiments Ni-SSZ-24 zeolite. results of the at operating conditions show that molecules reversibly mobilize as they exchange with zeolite ligands Ni during reaction. Microkinetic modeling was conducted basis free-energy profiles derived DFT-MD for these...
Water molecules cooperate to facilitate Al–O bond hydrolysis during zeolite dealumination at real steaming conditions.
The methanol-to-olefin process is a showcase example of complex zeolite-catalyzed chemistry. At real operating conditions, many factors affect the reactivity, such as framework flexibility, adsorption various guest molecules, and competitive reaction pathways. In this study, strength first principle molecular dynamics techniques to capture complexity shown by means two case studies. Firstly, behavior methanol water in H-SAPO-34 at 350 °C investigated. Hereby an important degree flexibility...
Enhanced molecular dynamics simulations of UiO-66 reveal a highly intrinsic dynamic behavior during activation and easy changes in the coordination number.
The methanol-to-hydrocarbon process is known to proceed autocatalytically in H-ZSM-5 after an induction period where framework methoxy species are formed. In this work, we provide mechanistic insight into the methylation within at high methanol loadings and varying acid site densities by means of first-principles molecular dynamics simulations. simulations show that stable clusters form zeolite pores, these commonly deprotonate active site; however, cluster size dependent on temperature...