A5021781650- Catalytic Processes in Materials Science
- Catalysis and Hydrodesulfurization Studies
- Catalysts for Methane Reforming
- Zeolite Catalysis and Synthesis
- Catalysis for Biomass Conversion
- Catalysis and Oxidation Reactions
- Electrocatalysts for Energy Conversion
- Thermochemical Biomass Conversion Processes
- Nanomaterials for catalytic reactions
- Biodiesel Production and Applications
- Carbon dioxide utilization in catalysis
- Mesoporous Materials and Catalysis
- Polyoxometalates: Synthesis and Applications
- Advanced Combustion Engine Technologies
- CO2 Reduction Techniques and Catalysts
- Carbon Dioxide Capture Technologies
- Biofuel production and bioconversion
- Analytical Chemistry and Chromatography
- Asymmetric Synthesis and Catalysis
- Analytical Methods in Pharmaceuticals
- Advanced Photocatalysis Techniques
- Quantum Dots Synthesis And Properties
- Supercapacitor Materials and Fabrication
- Silicon Nanostructures and Photoluminescence
- Copper-based nanomaterials and applications
National Renewable Energy Laboratory
2016-2025
Lawrence Berkeley National Laboratory
2005-2021
University of California, Berkeley
2005-2021
Colorado School of Mines
2017
Argonne National Laboratory
2008
University of California System
2008
Lafayette College
2002-2007
Advances in heterogeneous catalysis are driven by the structure–function relationships that define catalyst performance (i.e., activity, selectivity, lifetime). To understand these relationships, cooperative research is required: prediction and analysis using computational models, development of new synthetic methods to prepare specific solid-state compositions structures, identification catalytically active site(s), surface-bound intermediates, mechanistic pathways. In application...
We present a novel colloidal synthesis of alkyl-terminated Ge nanocrystals based on the reduction GeI4/GeI2 mixtures. The size (2.3−11.3 nm) was controlled by adjusting both Ge(IV)/Ge(II) ratio and temperature ramp rate following reductant injection. near-infrared absorption (1.6−0.70 eV) corresponding band-edge emission demonstrate highly tunable quantum confinement effects in prepared using this mixed-valence precursor method. A mechanism is proposed for observed control, which relies upon...
The catalytic deoxygenation of biomass fast pyrolysis vapors offers a promising route for the sustainable production liquid transportation fuels. However, clear understanding mechanistic details involved in this process has yet to be achieved, and questions remain regarding role catalyst support influence reaction conditions. In order gain insight into these questions, m-cresol was investigated over Pt/C Pt/TiO2 catalysts using experimental computational techniques. performance each...
We have synthesized alkylselenide reagents to replace the native oleate ligand on PbSe quantum dots (QDs) in order investigate effect of surface modification their stoichiometry, photophysics, and air stability. The reagent removes all QD results Se addition; however, complete enrichment does not occur, achieving a 53% decrease amount excess Pb for 2 nm diameter QDs 23% 10 QDs. Our analysis suggests that preferentially binds {111} faces, which are more prevalent smaller find attachment...
Transition metal carbides (TMCs) have demonstrated outstanding potential for utilization in a wide range of catalytic applications because their inherent multifunctionality and tunable composition. However, the harsh conditions required to prepare these materials limited scope synthetic control over physical properties. The development low-temperature, carburization-free routes TMCs would unlock versatility this class materials, enhance our understanding properties, enable cost-effective...
Ga(<sc>iii</sc>)-alkyl and alkoxide model compounds demonstrate XANES edge energy shifts similar to those in Ga dehydrogenation catalysts without a change oxidation state.
Bifunctional fixed-bed catalysts improve CFP performance.
Ex situ catalytic fast pyrolysis (CFP) is a promising route for producing fungible biofuels; however, this process requires bifunctional catalysts that favor C–O bond cleavage, activate hydrogen at near atmospheric pressure and high temperature (350–500 °C), are stable under high-steam, low hydrogen-to-carbon environments. Recently, early transition-metal carbides have been reported to selectively cleave bonds of alcohols, aldehydes, oxygenated aromatics, yet there limited understanding the...
Metal phosphides have been identified as a promising class of materials for the catalytic upgrading bio-oils, which are renewable and potentially inexpensive sources liquid fuels. Herein, we report facile synthesis series solid, phase-pure metal phosphide nanoparticles (NPs) (Ni2P, Rh2P, Pd3P) utilizing commercially available, air-stable metal–phosphine complexes in one-pot reaction. This single-source molecular precursor route provides an alternative method to access NPs with controlled...
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
The reaction kinetics of cyclohexene epoxidation using aqueous H2O2 oxidant and the highly selective catalyst BucapTaSBA15 were studied. was determined to be first-order in Ta(V) surface coverage. rate exhibited saturation with respect increasing concentrations H2O2. An Eley−Rideal mechanism equation may used describe kinetics, which are similar those for Ti(IV)SiO2-catalyzed epoxidations. observed also modeled by a double-displacement typically associated enzyme catalysts. In addition, 1H...
The translation of batch chemistries to high-throughput flow methods addresses scaling concerns associated with the implementation colloidal nanoparticle (NP) catalysts for industrial processes. A literature procedure synthesis Ni-NPs was adapted a continuous millifluidic (mF) method, achieving yields >60%. Conversely, NPs prepared in (B) reaction under conditions analogous gave only 45% yield. Both mF- and B-Ni-NP were supported on SiO2 compared Ni/SiO2 catalyst by traditional incipient...
Molybdenum carbide has been identified as a promising bifunctional catalyst in the deoxygenation of variety pyrolysis vapor model compounds. Although high activity demonstrated, complementary hydrogenation limited, especially for lignin-derived, aromatic The ability to control relative site densities acidic and functionalities represents design challenge these materials with goal improve under ex situ catalytic fast (CFP) conditions. Here we demonstrate that addition Pt Ni β-Mo2C resulted an...
High emissions of particulate matter from diesel engines presents a serious risk to human health and the environment. The addition oxygenated molecules fuels has been shown reduce soot formation during combustion. Polyoxymethylene ethers (POMEs) are novel class that can be produced biomass have potential used as soot-reducing fuel blendstocks. However, only few variations these studied thus far, those characterized present significant disadvantages could compromise current liquid systems...
The thermocatalytic hydrogenation of CO2 to hydrocarbons using a composite catalyst system in single reactor under mild reaction conditions was investigated, by combining methanol synthesis, dehydration and dimethyl ether homologation catalysts. High selectivity isoparaffins, which are versatile precursors sustainable aviation fuels, achieved. use Cu/BEA significantly improved both the conversion oxygenates hydrocarbon yield compared HBEA facilitating H-incorporation C-chain growth during...
A novel RCC process using modified CZA DFMs to produce renewable MeOH is presented. K/CZA provides exceptionally high productivity of compared previously reported attempts MeOH.
The thermolytic molecular precursor method was used to introduce site-isolated Ti(IV) centers onto the surface of a mesoporous SBA15 support. resulting Si-OH/Ti-OH sites Ti-SBA15 catalysts were modified with series (N,N-dimethylamino)trialkylsilanes, Me(2)N-SiMe(2)(R) (where R = Me, (n)Bu, or (n)Oc). Compared unmodified catalysts, surface-modified are more active in oxidation cyclohexene H(2)O(2) and exhibit significantly higher selectivity (up 58%) for oxide formation (vs allylic products)....
Abstract Surface modification of mesoporous SBA‐15 silica generated a hydrophobic environment for molybdenum diamine (Mo‐diamine) precursor solution, enabling direct growth isolated 1.9±0.4 nm α‐MoC 1− x nanoparticles (NPs) inside the pores support. The resulting NP catalysts are bifunctional, and compared to bulk β‐Mo 2 C, NPs exhibit greater acid‐site:H‐site ratio fraction stronger acid sites. results in higher decarbonylation (DCO) selectivity during acetic hydrodeoxygenation (HDO)...