A5008877055- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- Catalysts for Methane Reforming
- Electrocatalysts for Energy Conversion
- Catalysis and Hydrodesulfurization Studies
- CO2 Reduction Techniques and Catalysts
- Copper-based nanomaterials and applications
- Advanced Chemical Physics Studies
- Synthesis and Catalytic Reactions
- Electronic and Structural Properties of Oxides
- Advanced Photocatalysis Techniques
- Catalytic C–H Functionalization Methods
- Nanomaterials for catalytic reactions
- Chemical Synthesis and Reactions
- Nanoporous metals and alloys
- Asymmetric Hydrogenation and Catalysis
- Vanadium and Halogenation Chemistry
- Zeolite Catalysis and Synthesis
- Polyoxometalates: Synthesis and Applications
- Semiconductor Lasers and Optical Devices
- Nanocluster Synthesis and Applications
- Advanced Semiconductor Detectors and Materials
- Semiconductor Quantum Structures and Devices
- Green IT and Sustainability
- Electron and X-Ray Spectroscopy Techniques
BASF (United States)
2024
Brookhaven National Laboratory
2016-2023
Upton Hospital
2017-2018
Stony Brook University
2012-2018
United States Air Force Research Laboratory
2018
Georgetown University
2008
Hydrocarbons activate! Isolable β-diketiminato dicopper–nitrene complexes such as 1 derived from the reaction of [{(Cl2NN)Cu}2(μ-benzene)] and 1-adamantylazide are potent towards nitrene insertion into unactivated sp3-hybridized CH bonds. allows stoichiometric catalytic intermolecular amination hydrocarbons to give secondary amines (see scheme). Catalyst loadings low 0.05 mol % may be used. Detailed facts importance specialist readers published "Supporting Information". Such documents...
A water boost for methanol synthesis Model catalysts based on metals and metal oxides can dissociate methane (CH 4 ) at room temperature, converting it directly to 3 OH). Liu et al. show that one of these catalysts, an “inverted” CeO x -Cu 2 O oxide Cu(111), tunes the selectivity from forming CO surface CH groups, as revealed by ambient-pressure x-ray photoelectron spectroscopy. Theoretical modeling showed adsorbed blocks dissociation instead oxidizes reduced catalyst. Hydroxyl groups...
The transformation of methane into methanol or higher alcohols at moderate temperature and pressure conditions is great environmental interest remains a challenge despite many efforts. Extended surfaces metallic nickel are inactive for direct CH4 → CH3OH conversion. This experimental computational study provides clear evidence that low Ni loadings on CeO2(111) support can perform catalytic cycle the generation using oxygen water as reactants, with selectivity than ever reported ceria-based...
The results of kinetic tests and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) show the important role played by a ZnO–copper interface in generation CO synthesis methanol from CO2 hydrogenation. deposition nanoparticles ZnO on Cu(100) Cu(111), θoxi < 0.3 monolayer, produces highly active catalysts. catalytic activity these systems increases sequence: Cu(111) ZnO/Cu(111) ZnO/Cu(100). structure copper substrate influences performance interface. Furthermore, size metal–oxide...
Abstract Studies with a series of metal/ceria(111) (metal=Co, Ni, Cu; ceria=CeO 2 ) surfaces indicate that metal–oxide interactions can play very important role for the activation methane and its reforming CO at relatively low temperatures (600–700 K). Among systems examined, Co/CeO (111) exhibits best performance Cu/CeO has negligible activity. Experiments using ambient pressure X‐ray photoelectron spectroscopy dissociates on as 300 K—generating CH x species catalyst surface. The results...
The activation of methane and its dry reforming with CO2 was systematically studied over a series (2–30 wt %) Co (∼5 nm in size) loaded CeO2 catalysts, an effort to elucidate the interplay between during catalytic process using situ methods. results time-resolved X-ray diffraction (TR-XRD) show strong interaction CoOx–CeO2 systems at temperatures 200 350 °C. hydrogen produced by dissociation C–H bonds leads full reduction oxide, Co3O4 → CoO Co, partial ceria formation some Ce3+. Upon...
Single atom catalysts (SACs) have shown high activity and selectivity in a growing number of chemical reactions. Many efforts aimed at unveiling the structure–property relationships underpinning these activities developing synthesis methods for obtaining SACs with desired structures are hindered by paucity experimental capable probing attributes local structure, electronic properties, interaction support—features that comprise key descriptors their activity. In this work, we describe...
The interaction between a catalyst and reactants often induces changes in the surface structure composition of catalyst, which, turn, affect its reactivity. Therefore, it is important to study such using situ techniques under well-controlled conditions. We have used ambient pressure X-ray photoelectron spectroscopy stability Pt/Cu(111) single-atom alloy an CO. By directly probing Pt atoms, we found that CO causes slight segregation atoms at room temperature. In addition, while demonstrates...
Methane steam reforming (MSR) plays a key role in the production of syngas and hydrogen from natural gas. The increasing interest use for fuel cell applications demands development catalysts with high activity at reduced operating temperatures. Ni-based are promising systems because their low cost, but coke formation generally poses severe problem. Studies ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) indicate that CH4/H2O gas mixtures react Ni/CeO2(111) surfaces to form OH,...
Kohlenwasserstoffe aktiviert: Isolierbare β-Diketiminatodikupfernitren-Komplexe wie 1, die aus [{(Cl2NN)Cu}2(μ-Benzol)] und 1-Adamantylazid erhalten wurden, vermitteln Nitreninsertion in nichtaktivierte sp3-hybridisierte C-H-Bindungen. In Gegenwart von 1 gelingen stöchiometrische katalytische intermolekulare C-H-Aminierungen Kohlenwasserstoffen zur Bildung sekundären Aminen (siehe Schema). Katalysatorkonzentrationen nur 0.05 Mol-% können verwendet werden. Detailed facts of importance to...
Tin oxide nanoparticles supported on polycrystalline Pt exhibit a size-dependent promoting effect for the methanol oxidation reaction (MOR). We find that deposition of 2 nm SnO2 electrode surfaces results in an activity increase MOR up to 40 times over bare electrodes. Increasing size reduces enhancement, and at ∼20 nm, NPs show negligible surfaces. Density functional theory calculations suggest catalytic SnO2/Pt is strongly affected by binding energy adsorbed OH species nanoparticles. In...
Au(111) does not bind CO and O2 well. The deposition of small nanoparticles MgO, CeO2, TiO2 on produces excellent catalysts for oxidation at room temperature. In an inverse oxide/metal configuration there is a strong enhancement the oxide–metal interactions, are more active than conventional Au/MgO(001), Au/CeO2(111), Au/TiO2(110) catalysts. An identical trend was seen after comparing activity TiO2/Au Au/TiO2 powder model systems, increased following sequence: MgO/Au(111) < CeO2/Au(111)...
The surface chemistry of alcohol synthesis from CO2 hydrogenation has been investigated using kinetic testing, ambient pressure X-ray photoelectron spectroscopy (AP-XPS), and DFT calculations over a multicomponent system, where Pt ceria nanoparticles coexisted on titania template, Pt/CeOx/TiO2(110). Due to its high ability bind activate CO2, not seen for typical Cu–ZnO catalysts, the Pt–CeOx–TiO2 interface is excellent methanol, with some ethanol also being produced (21% selectivity)....
The start of operations at the National Synchrotron Light Source II (NSLS-II) Brookhaven Laboratory heralded a new beginning for photon-science-based research capabilities in catalysis. This facility builds on many years pioneering work that was conducted NSLS synergistically by scientists from academia, government labs, and industry. Over several decades, numerous discoveries catalysis were driven through emergence an arsenal tools exploited power emerging X-ray methods encompassing...
Mesoporous Co/CeO2 catalysts were found to exhibit significant activity for the high-temperature water-gas shift (WGS) reaction with cobalt loadings as low 1 wt %. The feature a uniform dispersion of within CeO2 fluorite type lattice no evidence discrete phase segregation. In situ XANES and ambient pressure XPS experiments used elucidate active state partially reduced cerium oxide doped oxidized atoms. XRD DRIFTS suggest facile reduction oxygen vacancy formation, particularly lower loadings....
A chemical approach to the deposition of thin films on solid surfaces is highly desirable but prone affect final properties film. To better understand origin these complications, initial stages atomic layer titania silica mesoporous materials were characterized. Adsorption–desorption measurements indicated that grow in a layer-by-layer fashion, as desired, initially exhibit surprisingly low densities, about one-quarter bulk titanium oxide. Electron microscopy, X-ray diffraction, UV/visible,...
The redox properties of titania films grown by ALD on SBA-15, a silica-based mesoporous material, were characterized as function thickness (that is, the number cycles used). 29Si CP/MAS NMR helped to identify nature surface species that form in initial stages deposition, and infrared absorption spectroscopy was used follow transition from silica surfaces. reducibility sites CO H2 studied ex situ using EPR with ambient-pressure XPS. It determined are amorphous easier reduce than crystalline...
We synthesized, characterized and tested Cu supported mesoporous CeO<sub>2</sub> catalyst for the water-gas shift (WGS) reaction.
Development of technologies for protection against chemical warfare agents (CWAs) is critically important. Recently, polyoxometalates have attracted attention as potential catalysts nerve-agent decomposition. Improvement their effectiveness in real operating conditions requires an atomic-level understanding CWA decomposition at the gas–solid interface. We investigated nerve agent Sarin and its simulant, dimethyl chlorophosphate (DMCP), by zirconium polytungstate. Using a multimodal approach,...
The splitting of water into molecular hydrogen and oxygen with the use renewable solar energy is considered one most promising routes to yield sustainable fuel. Herein, we report H2 evolution performance gallium doped TiO2 photocatalysts varying degrees Ga dopant. gallium(iii) ions induced significant changes in structural, textural electronic properties nanoparticles, resulting remarkably enhanced photocatalytic activity good stability for production. Ga3+ can act as hole traps that enable...