A5064987627- Catalytic Processes in Materials Science
- Electrocatalysts for Energy Conversion
- Catalysis and Oxidation Reactions
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Catalysis and Hydrodesulfurization Studies
- Machine Learning in Materials Science
- Catalysts for Methane Reforming
- Molecular Junctions and Nanostructures
- Fuel Cells and Related Materials
- CO2 Reduction Techniques and Catalysts
- Organometallic Complex Synthesis and Catalysis
- Catalysis for Biomass Conversion
- Zeolite Catalysis and Synthesis
- Chalcogenide Semiconductor Thin Films
- MXene and MAX Phase Materials
- Quantum Dots Synthesis And Properties
- Sulfur-Based Synthesis Techniques
- Metal-Organic Frameworks: Synthesis and Applications
- Ionic liquids properties and applications
- Advanced Chemical Physics Studies
- Advanced Materials Characterization Techniques
- Carbon dioxide utilization in catalysis
- Lignin and Wood Chemistry
- Polyoxometalates: Synthesis and Applications
National Renewable Energy Laboratory
2020-2024
Purdue University West Lafayette
2018-2024
Argonne National Laboratory
2019-2020
Abstract Iron- and nitrogen-doped carbon (Fe-N-C) materials are leading candidates to replace platinum catalysts for the oxygen reduction reaction (ORR) in fuel cells; however, their active site structures remain poorly understood. A postulate is that iron-containing sites exist primarily a pyridinic Fe-N 4 ligation environment, yet, molecular model generally feature pyrrolic coordination. Herein, we report hexaazacyclophane macrocycle, (phen 2 N )Fe, compare its spectroscopic,...
Alloying is an important strategy for the design of catalytic materials beyond pure metals. The conventional alloy catalysts however lack precise control over local atomic structures active sites. Here we report on investigation active-site ensemble effect in bimetallic Pd-Au electrocatalysts CO2 reduction. A series Pd@Au are synthesized by decorating Au nanoparticles with Pd controlled doses, giving rise to surfaces containing ensembles various sizes. Their activity electroreduction CO...
We report on the continuous fine-scale tuning of band gaps over 0.4 eV and electrical conductivity 4 orders magnitude in a series highly crystalline binary alloys two-dimensional electrically conducting metal-organic frameworks M3(HITP)2 (M = Co, Ni, Cu; HITP 2,3,6,7,10,11-hexaiminotriphenylene). The isostructurality permits direct synthesis (MxM'3-x)(HITP)2 (MM' CuNi, CoNi, CoCu) with metal compositions precisely controlled by precursor ratios. attribute both to changes free-carrier...
Abstract Supported nanoparticles are broadly employed in industrial catalytic processes, where the active sites can be tuned by metal-support interactions (MSIs). Although it is well accepted that supports modify chemistry of metal nanoparticles, systematic utilization MSIs for achieving desired performance still challenging. The developments with appropriate chemical properties and identification resulting main barriers. Here, we develop two-dimensional transition carbides (MXenes)...
Electrochemical capacitors (ECs) have emerged as reliable and fast-charging electrochemical energy storage devices that offer high power densities. Their use is still limited, nevertheless, by their relatively low density. Because specific surface area electrical conductivity are widely seen key metrics for improving the density overall performance of ECs, materials excellent conductivities but otherwise nonporous, such coordination polymers (CPs), often overlooked. Here, we report a new...
Catalysts based on earth-abundant elements, such as Ni and Mo, that can be used for the conversion of lignin-derived compounds are desirable. However, they usually exhibit low activity and/or selectivity toward target reaction, hydrodeoxygenation (HDO). For example, m-cresol in H2 over a typical Ni/SiO2 leads to ring hydrogenation at temperatures C–C hydrogenolysis CH4 high temperatures. Here, we report bimetallic Ni–Mo/SiO2 catalyst with Ni:Mo ratio ≈ 1 reduced an optimized temperature very...
Bi-Oxazoline (biOx) has emerged as an effective ligand framework for promoting nickel-catalyzed cross-coupling, cross-electrophile coupling, and photoredox-nickel dual catalytic reactions. This report fills the knowledge gap of organometallic reactivity (biOx)Ni complexes, including catalyst reduction, oxidative electrophile activation, radical capture, reductive elimination. The biOx displays no redox activity in (biOx)Ni(I) contrast to other chelating imine oxazoline ligands. lack results...
Electroreduction of carbon dioxide (CO2) or monoxide (CO) toward C2+ hydrocarbons such as ethylene, ethanol, acetate and propanol represents a promising approach carbon-negative electrosynthesis chemicals. Fundamental understanding the carbon─carbon (C-C) coupling mechanisms in these electrocatalytic processes is key to design development electrochemical systems at high energy conversion efficiencies. Here, we report investigation CO electreduction on single-atom copper (Cu)...
As a non-noble metal, Ni could offer significant economic advantages if used as catalyst for hydrodeoxygenation (HDO) of lignin-derived phenolics to produce aromatics. However, on unmodified catalysts, the desirable direct deoxygenation reaction must compete with high rates phenyl-ring hydrogenation and C–C hydrogenolysis reactions, which lead low aromatics yields. Here, we report bimetallic NiW/SiO2 (W/Ni = 1) prepared by coimpregnation that shows an HDO rate m-cresol almost order magnitude...
Abstract In heterogeneous catalysis, olefin oligomerization is typically performed on immobilized transition metal ions, such as Ni 2+ and Cr 3+ . Here we report that silica-supported, single site catalysts containing immobilized, main group Zn Ga ion sites catalyze ethylene propylene to an equilibrium distribution of linear olefins with rates similar The molecular weight products formed , while forms higher olefins. situ spectroscopic computational studies suggest unexpectedly occurs by the...
Transition-metal phosphides (TMPs) are versatile materials with tunable electronic and structural properties that have led to exceptional catalytic performances for important energy applications. Identifying predictive relationships between the performance key features such as composition, morphology, crystalline structure hinges on ability independently tune these variables within a TMP system. Here, we developed versatile, low-temperature solution synthesis route alloyed nickel phosphide...
The hydrogenation of CO
A precise understanding of the catalytic surface nanoparticles is critical for relating their structure to activity. For silica-supported Pt–Cr bimetallic catalysts containing nominal Cr/Pt molar ratios 0, 1.9, and 5.6, a fundamental difference in selectivity was observed as function composition propane dehydrogenation, suggesting different structures. The formation phases present were confirmed by synchrotron situ X-ray absorption spectroscopy (XAS) diffraction (XRD) nanoparticle reduction...
Precise synthesis and characterization of bimetallic nanoparticles are critical toward understanding structure–activity relationships in alkane dehydrogenation catalysis. Traditional synthetic methods for Pt alloy catalysts involve impregnation two metal salts onto high surface area supports followed by thermal reduction to form an alloy, which frequently results inhomogeneous alloying phase segregation excess oxides the material. In this work, we utilize colloidal synthesize supported Pt–In...
Atomic regulation of metal catalysts, especially the active surface, is key to optimizing catalytic performance. In this work, we tuned surface Pd coordination by varying bismuth loadings in Pd–Bi alloy system, facilitating different performances for propane dehydrogenation (PDH) and acetylene semihydrogenation model reactions. situ X-ray absorption spectroscopy, atom-resolved scanning transmission electron microscopy combined with elemental distribution analysis, infrared photoelectron...
The design of nanoparticles (NPs) with tailored morphologies and finely tuned electronic physical properties has become a key strategy for controlling selectivity improving conversion efficiency in variety important electrocatalytic transformations. Transition metal phosphide NPs, particular, have emerged as versatile class catalytic materials due to their multifunctional active sites composition- phase-dependent properties. Access targeted transition NPs controlled features is necessary...
Cobalt phosphide catalysts exhibit remarkable stability and selectivity for ethane dehydrogenation.
We demonstrate that single-atom alloy catalysts can be made by exposing physical mixtures of monometallic supported Cu and Pd to vinyl acetate (VA) synthesis reaction conditions. This induces the formation mobile clusters metal diacetate species drive extensive nanoparticle restructuring, leading atomic dispersion precious metal, smaller sizes than parent catalysts, high activity selectivity for both VA ethanol dehydrogenation reactions. approach is scalable appears generalizable other catalysts.
Controlled synthesis of Ni 2− x Rh P nanoparticle catalysts enables an understanding composition-dependent selectivity for the hydrodeoxygenation reaction phenolic molecules.
The amine–thiol solvent system has been used extensively to synthesize metal chalcogenide thin films and nanoparticles because of its ability dissolve various chalcogen precursors. While previous studies this have focused on understanding the dissolution precursors, here we provide an in-depth investigation chalcogens, specifically Se Te. Analytical techniques, including Raman, X-ray absorption, NMR spectroscopy high-resolution tandem mass spectrometry, were identify pathways for Te in...
We investigated the influence of P incorporation into a Ni catalyst on ethane dehydrogenation (EDH). Density functional theory calculations model Ni(111) and Ni2P(001) surfaces reveal that surface generally decreases adsorption energies fragments relevant to EDH at sites but itself participates in binding some these intermediates. These nonlinear influences cause CH3CH2–H activation occur with similar facility metal phosphide surfaces, while CH2CH–H activation, an indicator coking tendency,...