A5030553728- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- Metal-Organic Frameworks: Synthesis and Applications
- Polyoxometalates: Synthesis and Applications
- Mesoporous Materials and Catalysis
- X-ray Diffraction in Crystallography
- Catalysis and Hydrodesulfurization Studies
- Machine Learning in Materials Science
- Crystallization and Solubility Studies
- Zeolite Catalysis and Synthesis
- Electrocatalysts for Energy Conversion
- Carbon dioxide utilization in catalysis
- Chemical Synthesis and Reactions
- Advanced Photocatalysis Techniques
- Vanadium and Halogenation Chemistry
- Nanomaterials for catalytic reactions
- Oxidative Organic Chemistry Reactions
- Covalent Organic Framework Applications
- Magnetism in coordination complexes
- Asymmetric Hydrogenation and Catalysis
- CO2 Reduction Techniques and Catalysts
- Electrochemical Analysis and Applications
- Nanocluster Synthesis and Applications
- Metal complexes synthesis and properties
- Catalysts for Methane Reforming
Northwestern University
2015-2024
Division of Chemistry
2024
Sheridan College
2022
Moscow Technological Institute
2016
University of California, Berkeley
2002-2008
Consejo Nacional de Investigaciones Científicas y Técnicas
2007
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
2007
Universidad Nacional de La Plata
2007
National Academy of Sciences of Ukraine
2007
Institute of Organic Chemistry
2007
The modular nature of metal–organic frameworks (MOFs) enables synthetic control over their physical and chemical properties, but it can be difficult to know which MOFs would optimal for a given application. High-throughput computational screening machine learning are promising routes efficiently navigate the vast space have rarely been used prediction properties that need calculated by quantum mechanical methods. Here, we introduce Quantum MOF (QMOF) database, publicly available database...
Tandem catalysis couples multiple reactions and promises to improve chemical processing, but precise spatiotemporal control over reactive intermediates remains elusive. We used atomic layer deposition grow In2O3 Pt/Al2O3, this nanostructure kinetically the domains through surface hydrogen atom transfer, resulting in propane dehydrogenation (PDH) propylene by platinum, then selective combustion In2O3, without excessive hydrocarbon combustion. Other nanostructures, including platinum on or...
In this work, we leverage advances in computational screening based on periodic density functional theory (DFT) to study a diverse set of experimentally derived metal–organic frameworks (MOFs) with accessible metal sites for the oxidative activation methane. We find that thermodynamic favorability forming metal-oxo active site has strong, inverse correlation reactivity toward C–H bond wide range MOFs. This scaling relationship is found hold over MOFs varying coordination environments and...
Abstract With the goal of accelerating design and discovery metal–organic frameworks (MOFs) for electronic, optoelectronic, energy storage applications, we present a dataset predicted electronic structure properties thousands MOFs carried out using multiple density functional approximations. Compared to more accurate hybrid functionals, find that widely used PBE generalized gradient approximation (GGA) severely underpredicts MOF band gaps in largely systematic manner semi-conductors...
Abstract Active‐site/surface cooperativity can enhance heterogeneous organic and organometallic catalysis. We review the powerful role of solid surface in this context for generating local acidity and, as an inner‐sphere ligand, stabilizing immobilized supramolecular assemblies unsaturated complexes that are often unstable solution.
Ti, Nb, and Ta atoms substituted into the framework of zeolite *BEA (M-BEA) or grafted onto mesoporous silica (M-SiO2) irreversibly activate hydrogen peroxide (H2O2) to form pools metal-hydroperoxide (M-OOH) (M-(η2-O2)) species for alkene epoxidation. The product distributions from reactions with Z-stilbene, in combination time-resolved UV–vis spectra reaction between H2O2-activated materials cyclohexene, show that M-OOH surface intermediates epoxidize alkenes on Ti-based catalysts, while...
Supported metal oxides are important catalysts for selective oxidation processes like alkene epoxidation with H2O2. The reactivity of these is dependent on both identity and oxide structure. dependence the latter synthesis method can confound attempts at comparative studies across periodic table. Here, SiO2-supported Ti(IV), Zr(IV), Hf(IV), V(V), Nb(V), Ta(V) (all groups IV V) were synthesized by grafting a series related calixarene coordination complexes surface densities less than ∼0.25...
Metal–organic frameworks (MOFs) are a class of nanoporous materials with highly tunable structures in terms both chemical composition and topology. Due to their nature, high‐throughput computational screening is particularly appealing method reduce the time‐to‐discovery MOFs desirable physical properties. In this work, fully automated, periodic density functional theory (DFT) workflow for promising MOF candidates was developed benchmarked, specific focus on applications catalysis. As...
Developing structurally well-defined, supported oxide catalysts remains a significant challenge. Here, we report the grafting of Nb(V) sites onto nodes Zr-based metal organic framework (MOF) NU-1000 as stable, well-defined catalyst support. was deposited with loadings up to 1.6 mmol/g via two postsynthetic methods: atomic layer deposition in MOF, and solution-phase MOF. Difference envelope density measurements indicated that synthetic methods resulted different local structures ions within...
Metal-organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 N2 adsorption at several MOF families. A variety design handles identified that can be used modify redox activity centers, including changing functionalization linkers (replacing oxido...
Many industrially significant selective oxidation reactions are catalyzed by supported and bulk transition metal oxides. Catalysts for the synthesis of oxygenates, especially epoxidation, have predominantly focused on TiOx or co-condensed with SiO2, whereas much rest Groups 4 5 been less studied. We recently demonstrated through periodic trends using a uniform molecular precursor that niobium(V)-silica catalysts reveal highest activity selectivity efficient utilization H2O2 epoxidation...
Acid-catalyzed skeletal C–C bond isomerizations are important benchmark reactions for the petrochemical industries. Among those, o-xylene isomerization/disproportionation is a probe reaction strong Brønsted acid catalysis, and it also sensitive to local site density pore topology. Here, we report on use of phosphotungstic (PTA) encapsulated within NU-1000, Zr-based metal–organic framework (MOF), as catalyst isomerization at 523 K. Extended X-ray absorption fine structure (EXAFS), 31P NMR, N2...
The modular structure of metal–organic frameworks (MOFs) makes them promising platforms for catalyst design and elucidating structure/performance relationships in catalysis. In this work, we systematically varied the composition metal nodes (Fe2M) MOF PCN-250 used density functional theory (DFT) to identify catalysts light alkane C–H bond activation. Oxidative dehydrogenation (ODH) alkanes was studied using N2O as oxidant understand reactivity oxocentered Fe2M found PCN-250, where Fe ions...
Solid supports are crucial in heterogeneous catalysis due to their profound effects on catalytic activity and selectivity. However, elucidating the specific arising from such remains challenging. We selected a series of metal-organic frameworks (MOFs) with 8-connected Zr6 nodes as deposit molybdenum(VI) onto study pore environment topology resulting Mo-supported catalysts. As characterized by X-ray absorption spectroscopy (XAS) single-crystal diffraction (SCXRD), we modulated chemical...
Metallocalixarenes were grafted onto silica using a surface organometallic approach and shown to be active selective catalysts for epoxidation of alkenes organic hydroperoxides. Calixarene-Ti(IV) precursors anchored at densities from 0.1 near-monolayer coverages (0.025-0.25 calixarene nm(-2)). Several spectroscopic methods independently detected calixarene-Ti(IV) connectivity before after catalysis. Kinetic analyses cyclohexene confirmed that the sites on significantly more than their...
Strongly Brønsted acidic silica–alumina materials are workhorse catalysts in petroleum processes, including cracking, isomerization, and hydrocarbon synthesis. Here thin, conformal overcoats of SiO2, 2–5 nm by TEM, were synthesized on pre-existing Al2O3 supports stepwise addition tetraethyl orthosilicate under basic conditions, the surfaces interrogated N2 physisorption along with NH3 pyridine chemisorption. SiO2 layers thicker than 5 give largely inert surfaces, but adding only 2 is shown...
Heterometallic CeIV/M oxo clusters are underexplored yet and can benefit from synergistic properties combining cerium other metal cations to produce efficient redox catalysts. Herein, we designed synthesized a series of new Ce12V6 with different capping ligands: Ce12V6-SO4, Ce12V6-OTs (OTs: toluenesulfonic acid), Ce12V6-NBSA (NBSA: nitrobenzenesulfonic acid). Single crystal X-ray diffraction (SCXRD) for all three structures reveals cubane core formulated [Ce12(VO)6O24]18+ on the edges cube,...
Oxidative dehydrogenation of propane (ODHP) to propylene could have a significant impact on the production this critical chemical intermediate, if appropriate catalysts can be discovered. Recently, heterogeneous based boron (oxides and nitrides) been demonstrated promising for ODHP, but their active sites not conclusively identified. Here, we report that deposition differently sized boronic acids into micropores silica supports results in different distributions surface borate species after...
Calixarene-Ti complexes were grafted onto SiO2 (0.18-0.24 Ti nm-2) to form isolated and accessible centers persistently coordinated multidentate calixarene ligands. Grafted Ti-tert-butylcalix[4]arenes gave K-edge absorption spectra with pre-edge features at 4968.6-4968.9 eV, independently of surface density their use in epoxidation catalysis. The structure reactivity Ti-calix[4]arenes weakly dependent on thermal treatment below 573 K, the relative rates trans- cis-alkenes showed that ligands...
Calix[4]arenes and thiacalix[4]arenes, cyclic tetramers of phenol, are synthesized with para position (upper rim) tert-butyl, Br, NO2 groups grafted covalently onto surfaces TiO2 nanoparticles up to a geometrical maximum surface density 0.30 nm-2. Grafted calixarenes hydrolytically stable shown exist in their 'cone' conformation from comparison model materials by grafting preformed calixarene−Ti complexes. Individually, protonated absorb only UV light, but calixarene−TiO2 hybrid...
Supported amines are considered as adsorbents to replace aqueous for carbon capture and CO(2) capture/conversion into chemicals. Here, grafted SiO(2) or Ti-SiO(2) by using aminopropyl triethoxysilane (APTES) (3-triethoxysilylpropyl)-tert-butylcarbamate (TESPtBC) then removing the carbamate group introduced latter mild heating 'deprotect' amine. Structures verified (13) C cross polarization magic angle spinning (CP/MAS) NMR spectroscopy, acid titration, thermogravimetric analysis, elemental...