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[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
U. Minn. team proposes strategy for automated selection of optimal biomass-derived fuel blends and synthesis paths
May 07, 2013
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| Proposed strategy for connecting automated network generation and optimization. Credit: ACS, Marvin et al. Click to enlarge. |
Researchers at the University of Minnesota are proposing a novel strategy that simultaneously identifies (a) the most desirable biomass-derived chemical products for an application of interest, such as fuels, and (b) the corresponding synthesis routes.
In a paper published in the ACS journal Energy & Fuels, they describe the strategy, and then apply it to identify potential renewable oxygenates and hydrocarbons obtained from heterogeneous catalysis of biomass that can be blended with gasoline to satisfy ASTM specifications.
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Brookhaven team develops molybdenum-soy catalyst that rivals performance of noble metals for hydrogen production
April 24, 2013
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| This illustration depicts the synthesis of a new hydrogen-production catalyst from soybean proteins and ammonium molybdate. Mixing and heating the ingredients leads to a solid-state reaction and the formation of nanostructured molybdenum carbide and molybdenum nitride crystals. The hybrid material effectively catalyzes the conversion of liquid water to hydrogen gas while remaining stable in an acidic environment. Source: BNL. Click to enlarge. |
Researchers at the US Department of Energy’s Brookhaven National Laboratory (BNL) have developed a low-cost, stable, effective catalyst made from earth-abundant molybdenum and common soybeans (MoSoy).
In a paper published in the RSC journal Energy & Environmental Science, the team reports that the catalyst—composed of a catalytic β-Mo2C phase and an acid-proof γ-Mo2N phase, drives the hydrogen evolution reaction (HER) with low overpotentials, and is highly durable in a corrosive acidic solution over a period exceeding 500 hours. When supported on graphene sheets, the MoSoy catalyst exhibits very fast charge transfer kinetics, and its performance rivals that of noble-metal catalysts such as platinum (Pt) for hydrogen production.
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PNNL solar thermochemical reaction system can reduce fuel consumption in natural gas power plants by about 20%; future potential for transportation fuels
April 11, 2013
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| PNNL’s thermochemical conversion device is installed in front of a concentrating solar power dish. Photo: PNNL. Click to enlarge. |
A new concentrating solar power system developed by Pacific Northwest National Laboratory (PNNL) can reduce the fuel consumption of a modified natural-gas combined-cycle (NGCC) power plant by about 20%. The system converts natural gas into syngas—with higher energy content than natural gas—using a thermochemical conversion device installed in front of a concentrating solar power dish. The power plant then combusts the more energy dense syngas to produce electricity.
PNNL’s system uses a mirrored parabolic dish to direct sunbeams to a central point, where the thermochemical device uses the solar heat to produce syngas form natural gas. About four feet long and two feet wide, the device contains a chemical reactor and several heat exchangers. Concentrated sunlight heats up the natural gas flowing through the reactor’s channels, which hold a catalyst that helps turn natural gas into syngas.
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New catalysts convert ethanol to butanol with high selectivity; potential low-cost upgrade for ethanol plants
Researchers at the University of Bristol (UK) have developed a new family of catalysts that enables the conversion of ethanol into n-butanol—a higher alcohol with better characteristics for transportation applications than ethanol—with selectivity of more than 95% at good conversion. The team presented a pair of papers on their work at the Spring meeting of the American Chemical Society this week in New Orleans.
While butanol has emerged as a potential sustainable liquid fuel replacement for gasoline, development of biosynthetic pathways for its synthesis are challenged by very low conversion and modest selectivity, they noted. Although catalytically upgrading the more readily available bioethanol to butanol is theoretically attractive, this has been hampered by modest selectivity in most cases.
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EBEI researchers shed light on how multiple cellulase enzymes attack cellulose; potential avenue to boosting sugar yields for biofuels
April 08, 2013
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| PALM enables researchers to quantify how and where enzymes are binding to the surface of cellulose in heterogeneous surfaces, such as those in plant cell walls. Source: Berkeley Lab. Click to enlarge. |
Researchers with the Energy Biosciences Institute, University of California, Berkeley have provided insight into how multiple cellulase enzymes attack cellulose, potentially yielding a way to improve the collective catalytic activity of enzyme cocktails that can boost the yields of sugars for making fuels.
Increasing the sugar yields from cellulosic biomass to help bring down biofuel production costs is essential for the widespread commercial adoption of these fuels. A paper on their work is published in Nature Chemical Biology.
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Primus Green Energy to support gas-to-liquids research at Princeton University; comparing STG+ to other GTL platforms
March 28, 2013
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| Schematic diagram of the Primus STG+ process. Click to enlarge. |
Primus Green Energy Inc., developer of a proprietary process to produce gasoline and other fuels from biomass and/or natural gas (earlier post), will provide financial support to engineers at Princeton University for general research on synthetic fuels, which will include assessments of various gas-to-liquids (GTL) technologies—including Primus’ own STG+—for sustainability and economic viability.
STG+ technology converts syngas into drop-in high-octane gasoline and jet fuel with a conversion efficiency of ~35% by mass of syngas into liquid transportation fuels (the highest documented conversion efficiency in the industry) or greater than 70% by mass of natural gas. The fuels produced from the Primus STG+ technology are very low in sulfur and benzene compared to fuels produced from petroleum, and they can be used directly in vehicle engines as a component of standard fuel formulas and transported via the existing fuel delivery infrastructure.
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UNSW team develops bio-inspired catalytic approach to chemical reduction for production of fuels and chemicals
March 25, 2013
Scientists at the University of New South Wales (Australia) have developed a new bio-inspired method for carrying out chemical reduction—an industrial process used to produce fuels and chemicals. A report on their work is published in the journal Angewandte Chemie.
Chemical reduction involves the addition of electrons to a substance, and is the basis of making many fuels, including the sugars that plants produce during photosynthesis. The catalyst designed by the team led by Associate Professor Stephen Colbran of the UNSW School of Chemistry mimics the activity of naturally occurring metallo-(de)hydrogenase enzymes that catalyse reduction, such as alcohol dehydrogenase in yeast, that helps produce alcohol from sugar.
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Univ. of Calgary team developing nanocatalysts for underground upgrading of heavy oil and bitumen; possible “next generation” of oil sands production
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| Total injected hot fluid and total produced liquid for the nanocatalyst experiments at temperatures of 320 and 340 °C. Credit: ACS, Hashemi et al. Click to enlarge. |
Researchers at the University of Calgary are developing ultra-dispersed (UD) nanocatalysts for the in situ upgrading of heavy oil and bitumen from deep reservoirs. Such an “underground refinery” approach is one of the alternatives to surface upgrading that may become the next-generation of oil sands industry improvement, they suggest in a paper published in the ACS journal Energy & Fuels.
One of the challenges of such an approach is the placement of the catalyst deep into the heavy oil plume by transporting a catalyst suspension through the sand medium. In their paper, they report that water-in-vacuum gas oil microemulsions containing trimetallic (W, Ni, and Mo) ultradispersed colloidal nanoparticles could penetrate inside the porous medium and react with the bitumen, resulting in enhanced recovery.
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Yale team develops new silver-palladium core-shell catalyst for direct alcohol fuel cells
March 19, 2013
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| The core-shell silver-palladium catalyst. Source: Yale. Click to enlarge. |
Yale researchers have synthesized a silver-palladium core-shell catalyst supported on multi-walled carbon nanotubes (Ag@Pd/MWNTs) for use in fuel cells. The new platinum-free catalysts are are highly active and alcohol-tolerant for oxygen reduction reactions (ORR) in alkaline media. A paper on their work is published in the journal Applied Catalysis B.
The new, platinum-free catalyst has a unique core-shell structure; the thin shell is palladium, the core silver. This allows for higher catalytic activity and greater tolerance for impurities than standard platinum-based catalysts. Particles of silver coated with palladium cover the surface of multi-walled carbon nanotubes, promoting the reduction of oxygen over the oxidation of alcohol.
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Researchers use LCLS to get real-time view of chemical reaction; important insight into how catalysts work
March 15, 2013
An international team of researchers has used the ultrafast, ultrabright X-ray pulses of the Linac Coherent Light Source (LCLS) at the US Department of Energy’s (DOE) SLAC National Accelerator Laboratory (earlier post) to gain unprecedented views of a catalyst in action, an important step in the effort to develop cleaner and more efficient energy sources. A paper on their work is published in the journal Science.
The scientists used LCLS, together with computerized simulations, to probe the electronic structure of CO molecules as their chemisorption state on a ruthenium catalyst sample changed upon exciting the substrate. The study revealed surprising details of a short-lived early state in the chemical reaction, offering important clues about how catalysts work and launching a new era in probing surface chemistry as it happens.
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Stanford GCEP awards $6.6M to 7 projects; focus on combining energy conversion with carbon-neutral fuel production
March 13, 2013
Stanford’s Global Climate and Energy Project (GCEP) is awarding $6.6 million to seven research teams—six from Stanford and one from Carnegie Mellon University—to advance research on technologies for renewable energy conversion to electricity or fuels and for capturing CO2 emissions and converting CO2 to fuels.
The 7 awards bring the total number of GCEP-supported research programs to 104, with total funding of approximately $125 million since the project’s launch in 2002.
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IACS team develops high-performing bio-inspired electrocatalyst for hydrogen generation in an aqueous medium
March 11, 2013
Researchers from the Indian Association for the Cultivation of Science (IACS), an autonomous—and the oldest—research institute in India, have developed a high-performing bio-inspired catalyst (an Fe−Fe hydrogenase mimic immobilized on graphite surfaces) for electrocatalytic hydrogen generation in an aqueous medium.
In a paper published in the journal ACS Catalysis, they report that the catalyst shows a turnover frequency of 6,400 s−1 at −0.5 V and an onset potential of −0.36 V vs NHE (normal hydrogen electrode, an early standard for zero potential). Prolonged electrolysis shows that the catalyst has a turnover number ≫108 and a Faradaic efficiency > 95%. Even at pH 2, more than 400 s−1 is obtained. The catalyst can be immobilized on inexpensive carbon electrodes, such as those used in domestic Zn-carbon dry batteries, to generate H2 from acid aqueous solutions.
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China-US team develops new platinum-cobalt nanocatalysts for low-temperature aqueous phase Fischer-Tropsch synthesis
March 07, 2013
Researchers from China and the US have developed Pt−Co nanoparticles (NPs) which proved to be effective and efficient catalysts for aqueous-phase Fischer-Tropsch synthesis (FTS) at 433 K (160 °C)—a lower operational temperature than can be achieved with conventional catalysts. A report on their work is published in the Journal of the American Chemical Society.
Fischer−Tropsch synthesis is a well-established catalytic process that converts syngas derived from fossil fuels or biomass to liquid fuel products. As the process is highly exothermic and thermodynamically favored at low temperature, it is desirable to develop a catalyst system that could facilitate working at low reaction temperature while maintaining excellent catalytic performance, they note.
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Researchers develop new Fischer-Tropsch catalyst and production method; Total patents both
March 05, 2013
A team of researchers led by University of Amsterdam (UvA) chemists has developed new Fischer-Tropsch catalysts—consisting of ultra-thin cobalt shells surrounding inexpensive iron oxide cores—that can be used to produce synthetic fuels from natural gas and biomass. The method used to produce the catalysts is based on an approach previously optimized for preparing magnetic tape for audio cassettes in the 1960s.
France-based energy major Total, which was part of the research team, has patented the new catalysts and the method for their preparation, naming the UvA researchers as co-inventors. The research has just been published online as a VIP (very important paper) communication in the journal Angewandte Chemie.
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New low-temperature catalytic process for producing hydrogen from methanol; potential future application for fuel cell vehicles
February 28, 2013
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| (a) Schematic pathway for a homogeneously catalyzed methanol reforming process via three discrete dehydrogenation steps. (b) Best performing catalysts. Nielsen et al. Click to enlarge. |
Researchers from Germany and Italy have developed an efficient low-temperature catalytic process to produce hydrogen from methanol. Hydrogen generation by this method proceeds at 65–95 °C (149-203 °F) and ambient pressure with excellent catalyst turnover frequencies (4,700 per hour) and turnover numbers (exceeding 350,000). This could make the delivery of hydrogen on mobile devices—and hence the use of methanol as a practical hydrogen carrier—eventually feasible, the team suggests in a paper published in the journal Nature.
One of the challenges to hydrogen fuel cell vehicles is the efficient on-board storage of adequate amounts of the hydrogen gas required for fuel cell operation due to the properties of the gas. Methanol conceptually is an interesting alternative, as it is a liquid at room temperature (easier transportation and handling) and contains 12.6% hydrogen. However, current methanol reforming technologies for the production of hydrogen are conducted at high temperatures (> 200 °C) and high pressures (25–50 bar), limiting potential mobile applications of “so-called reformed methanol fuel cells”, they note.
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PNNL team develops bio-inspired iron-based catalyst for hydrogen fuel cells
February 18, 2013
Researchers at the US Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) have developed a new biologically inspired catalyst that is the first iron-based catalyst that converts hydrogen directly to electricity. The catalyst could support the achievement of more affordable fuel cells.
The team developed a molecular complex of iron—CpC6F5Fe(PtBu2NBn2)(H)—as a rationally designed electrocatalyst for the oxidation of hydrogen at room temperature, with turnover frequencies of 0.66–2.0 s−1 and low overpotentials of 160–220 mV. A paper on their work is published in Nature Chemistry.
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Researchers use LCLS x-ray laser to view simultaneously the structure and chemical behavior of Photosystem II catalyst; major step in studying catalytic processes
February 14, 2013
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| Conceptual view shows a Photosystem II crystal hit by a femtosecond X-ray pulse. The resulting diffraction pattern (left) is used to map the overall protein structure. The emission spectrum (right) is simultaneously collected and used to probe the intactness and oxidation state of the crystal’s key Mn complex. (Credit: Greg Stewart, SLAC) Click to enlarge. |
An international team of researchers has used an X-ray laser at the Department of Energy’s (DOE) SLAC National Accelerator Laboratory to look simultaneously at the structure and chemical behavior of the Photosystem II catalyst involved in photosynthesis for the first time. The work, made possible by the ultrafast, ultrabright X-ray pulses at SLAC’s Linac Coherent Light Source (LCLS), is a breakthrough in studying atomic-scale transformations in photosynthesis and other biological and industrial processes that depend on catalysts, which efficiently speed up reactions.
This pioneering experimental technique can be used to further study photosynthesis and other catalytic reactions, the researchers said in a paper published in the journal Science.
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Southern Research Institute wins $1.5M DOE award to test new coal-biomass-to-liquids method; seeking to reduce cost and environmental impact
January 08, 2013
Southern Research Institute has entered into a $1.5-million cooperative agreement with the US Department of Energy to test an innovative method for producing liquid transportation fuels from coal and biomass, thereby improving the economics and lifecycle impacts of coal-to-liquid (CTL) and coal-biomass-to-liquid (CBTL) processes.
The novel approach eliminates the conventional Fischer-Tropsch (FT) product upgrading and refining steps and enhances the ability of CTL and CBTL processes to compete with petroleum-based processes.
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Univ. of Washington and partners working to engineer microbes for conversion of methane to lipids for processing into liquid intermediates for diesel or jet fuels
January 03, 2013
In a $4.8-million project funded by ARPA-E (earlier post), the University of Washington, the US Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL), Johnson-Matthey, and Lanza Tech are working to develop optimized microbes to convert methane found in natural gas into lipids for further processing into an intermediate liquid for diesel or jet fuel.
The University of Washington is taking the lead and focusing on genetically modifying the microbes. NREL will be in charge of fermentation to demonstrate the productivity of the microbes, both the natural organism and the genetically-altered varieties. NREL will also extract the lipids from the organisms and analyze the economic potential of the plan.
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Researchers develop four-step catalytic process to produce petroleum refinery feedstocks from biomass sugars
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| Molar carbon selectivities for different renewable petroleum refinery feedstocks obtained by hydrocycloaddition and hydrodeoxygenation of condensed furfural–acetone mixtures. Source: Olcay et al. Click to enlarge. |
A team of researchers led by James Dumesic and George Huber, both now at the University of Wisconsin-Madison, have demonstrated how C5 sugars derived from hemicellulose can be converted into a high-quality petroleum refinery feedstock via a four-step catalytic process. An open-access paper on their work is published in the RSC journal Energy & Environmental Science.
The renewable petroleum feedstock comprises normal, branched and cyclic alkanes up to 31 carbons in length and is similar in composition to the feedstocks produced in a petroleum refinery from crude oil. The new process can be tuned to adjust the size of the liquid alkanes.
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Platinum on tin-doped indium oxide as promising next-generation catalyst for PEM fuel cells; exceeding DOE 2015 mass activity target
January 02, 2013
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| Mass activity and specific activity at 0.9V vs RHE (reversible hydrogen electrode) for Pt/ITO and Pt/C. Mass and specific activities are given as kinetic current densities (jk) normalized in reference to the loading amount and ECSA of metal, respectively. Credit: ACS, Liu and Mustain. Click to enlarge. |
Researchers at the University of Connecticut report that a new catalyst material using tin (Sn)-doped indium oxide (ITO) nanoparticles (NPs) as a high stability non-carbon support for platinum (Pt) NPs is a very promising candidate as a next-generation catalyst for proton exchange membrane fuel cells (PEMFCs).
In a paper published in the Journal of the American Chemical Society, they report that the PT/ITO catalyst showed mass activity of 621 ± 31 mA/mgPt—far exceeding the 2015 US Department of Energy (DOE) goal for Pt mass activity of 440 mA/mgPt. The stability of the Pt/ITO material was also “very impressive” under harsh conditions for ORR electrocatalysts in which state-of-the-art Pt/C electrocatalysts typically show very poor stability, they reported.
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New catalyst for efficient bi-reforming of methane from any source for methanol and hydrocarbon synthesis; “metgas”
December 30, 2012
Researchers at the Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, have developed a new catalyst based on nickel oxide on magnesium oxide (NiO/MgO) that is effective for the bi-reforming with steam and CO2 (combined steam and dry reforming) of methane as well as natural gas in a tubular flow reactor at elevated pressures (5−30 atm) and temperatures (800−950 °C).
In a paper published in the Journal of the American Chemical Society, they report that the bi-reforming effectively converts methane and its natural sources (natural or shale gas, coal-bed methane, methane hydrates) to what they call “metgas”, a 2/1 H2/CO mixture directly applicable for subsequent well-studied methanol synthesis with high selectivity. A typical single pass conversion at 7 atm is about 70−75%, which can be increased to 80−85% by adjusting the feed gas composition. Unreacted feed gases can be recycled.
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Highly efficient non-precious metal electrocatalyst for ORR in fuel cells and metal-air batteries
December 18, 2012
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| a)Current–voltage and b) power–voltage curves of Zn–air cells with one of the nanotetrapod non-precious metal and 20% Pt/C catalysts. A gas diffusion layer without any catalysts was used as the baseline air electrode for comparison. Source: Lee et al. Click to enlarge. |
A team of S. Korean and American scientists led by Dr. Jaephil Cho at Ulsan National Institute of Science and Technology (UNIST) reports on a newly developed, highly efficient non-precious metal electrocatalyst for the oxygen reduction reaction (ORR) in the journal Angewandte Chemie.
Inspired by the tetrapod structures of a breakwater, the novel material for electrodes is created from affordable melamine foam and carbon black. The unique porous architecture greatly facilitates rapid mass transport, while the N-doped ketjenblack and Fe/Fe3C-functionalized surface of the framework significantly enhance the ORR activity of cathodes for fuel cells and metal-air batteries.
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NREL and Johnson Matthey in 5-Year collaboration on catalytic fast pyrolysis for drop-in biofuels
December 14, 2012
The US Department of Energy’s National Renewable Energy Laboratory (NREL) will partner with Johnson Matthey, a global specialty chemicals company, in a five-year, $7-million effort to produce economically drop-in gasoline, diesel and jet fuel from non-food biomass feedstocks.
The goal is to improve vapor-phase upgrading during the biomass pyrolysis process in order to lower costs and speed production of lignocellulose-based fuels; as part of the work, Johnson Matthey will supply and develop innovative new catalytic materials for such upgrading.
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€3.9M European project to develop automotive fuel cell MEAs with ultra-low platinum loadings
November 09, 2012
ITM Power announced it received confirmation of a €3.9 million (US$4.96 million) grant award to a consortium to develop Proton Exchange Membrane (PEM) Fuel Cell Membrane Electrode Assemblies (MEAs) with ultra-low platinum loadings for automotive applications. ITM Power’s share of this award is €0.59 million (US$.75 million), recognized over the three years of the program.
One of the main cost issues for the commercialization of fuel cells is the amount of the platinum (Pt) that is used as catalyst in the cathode where the oxygen reduction reaction (ORR) takes place. Known as the IMPACT project and funded under the Seventh Framework Programme, the project aims to improve the lifetime (>5,000 hours) of PEM fuel cells with MEAs containing ultra-low platinum loadings (<0.2 mg/cm2).
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Berkeley researchers integrate ABE fermentation and chemical catalysis to produce bio-hydrocarbon blend stocks from sugars at high yields
November 07, 2012
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| A general approach to the catalyzed production of biofuels from the ABE fermentation mixture. Source: Anbarasan et al. Click to enlarge. |
Researchers at UC Berkeley have devised a new process that integrates chemical catalysis with extractive fermentation selectively to produce gasoline, jet and diesel blend stocks from lignocellulosic and cane sugars at yields near their theoretical maxima.
The process efficiently converts acetone–n-butanol–ethanol (ABE) fermentation products produced by Clostridium acetobutylicum into ketones via a palladium-catalyzed alkylation. These ketones can be deoxygenated to paraffins; these paraffins—from pentane to undecane—are components of gasoline, diesel and jet fuel. Tuning of the reaction conditions permits the production of either gasoline or jet and diesel precursors.
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New platinum-cobalt nanocatlysts for fuel cells greatly enhance activity and stability and cut costs
October 31, 2012
A research team at the Energy Materials Center at Cornell (EMC2) is developing platinum-cobalt nanoparticles with a platinum enriched shell that show improved catalytic activity for the oxygen reduction reaction in fuel-cell applications. The new class of Pt–Co nanocatalysts—composed of ordered Pt3Co intermetallic cores with a 2–3 atomic-layer-thick platinum shell—exhibited a more than 200% increase in mass activity and a more than 300% increase in specific activity when compared with the disordered Pt3Co alloy nanoparticles as well as Pt/C.
The new material could reduce the cost by a factor of five, according to Héctor Abruña, the E.M. Chamot Professor of Chemistry and Chemical Biology, senior author of a paper describing the work published in the journal Nature Materials. The mass activity for the oxygen reduction reaction is the highest among the Pt–Co systems reported in the literature under similar testing conditions, the authors noted. These ordered nanoparticles provide a new direction for catalyst performance optimization for next-generation fuel cells, they suggested.
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IACT team using ALD to build nanobowls for tailored catalysts for biofuel production
October 27, 2012
A team of scientists from the Institute for Atom Efficient Chemical Transformations (IACT)—an Energy Frontier Research Center (earlier post) led by Argonne National Laboratory (ANL), and including Northwestern University, the University of Wisconsin and Purdue University—is using atomic layer deposition (ALD) to build nanoscale “bowls” that protect metal catalysts from the harsh conditions of biofuel refining.
In recent years, nanoparticles of metals such as platinum, iridium and palladium supported on metal oxide surfaces have been considered as catalysts to convert biomass into alternative fuels as efficiently as possible. Unfortunately, under typical biorefining conditions where liquid water may reach temperatures of 200 °C and pressures of 4,100 kilopascals (597 psi), the tiny metal nanoparticles can agglomerate into much larger particles which are not catalytically active. Additionally, these extreme conditions can dissolve the support.
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China-US team develops inkjet-printing assisted method for high-throughput generation of catalyst libraries
October 19, 2012
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| Inkjet printing assisted cooperative-assembly (IJP-A) synthesis uses stabilized “inks”, a specially modified color management system, and multidimensional group testing rapidly to identify optimal catalysts. Credit: ACS, Liu et al. Click to enlarge. |
A team from Zhejiang University (China) and the University of California, Santa Barbara have developed an inkjet printing assisted cooperative-assembly technique for ultrafast explorations in combinatorial chemistry. The system can precisely synthesize up to eight-component meso-structured metal oxides catalysts at a rate of 1,000,000 formulations per hour.
The method can also be applied to explore most multiple-component metal oxides, metal sulfides, metal nitrides, and metal complexes for functional materials and establish composition-structure−property relationships. The technique should have immediate practical implications and advantages for addressing biology, energy, and environment challenges, the team suggests in a paper published in the ACS journal Nano Letters.
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Cobalt/cobalt oxide/graphene catalyst shows comparable activity and better stability as fuel cell catalyst than platinum
October 17, 2012
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| Left: CoO shell is shown in green, Co core in black. Right: Nanoparticles of cobalt attach themselves to a graphene substrate in a single layer. Credit: Sun Lab/Brown University. Click to enlarge. |
Chemists at Brown University have engineered a cobalt/cobalt oxide/graphene catalyst for the oxygen reduction reaction in fuel cells that shows comparative activity and better stability than a commercial platinum nanoparticle catalyst supported on carbon (C–Pt). Their report appears in the journal Angewandte Chemie International Edition.
The team led by Shouheng Sun and his students used a solution-phase self-assembly approach to produce Co/CoO core/shell nanoparticles deposited on graphene (G–Co/CoO NPs). They found that the catalytic activity for the oxygen reduction reaction in O2-saturated KOH solution depends on the thickness of the CoO shell.
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Researchers identify ignition behavior of catalysts in catalytic converters; more efficient catalysts for cold-start conditions
October 08, 2012
Researchers from the Vienna University of Technology (Austria), Chalmers University of Technology (Sweden) and the Fritz-Haber-Institute of the Max-Planck-Society (Germany) have identified the inherent reaction behavior of different catalysts for ignition in the CO oxidation reaction in catalytic converters.
The results, presented in an open access paper published in the journal Angewandte Chemie International Edition, can make it possible to perform targeted searches for manufacturing processes for catalytic converters with lower ignition temperatures—i.e., for catalytic converters that can operate more efficiently just after a cold-start.
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Researchers use PEM fuel cell reactor to convert biomass-derived acetone into isopropanol; new biomass to fuels pathway
October 03, 2012
A team from the University of Wisconsin-Madison, University of Massachusetts-Amherst and Gwangju Institute of Science and Technology of South Korea has demonstrated the feasibility of using proton-exchange-membrane (PEM) reactors electrocatalytically to reduce biomass-derived oxygenates into renewable fuels and chemicals.
George Huber, UW-Madison professor of chemical and biological engineering, and his collaborators used a PEM fuel cell reactor to reduce the model biomass compound acetone into isopropanol— a chemical compound with a wide variety of pharmaceutical and industrial applications, including as a gasoline additive—on an unsupported platinum cathode. The advance paves the way for researchers to convert biomass molecules such as glucose into hexanes, which are significant components of gasoline currently derived by refining crude oil.
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Chevron Lummus and ARA partner with Agrisoma, US AFRL and Canada’s NRC to evaluate and to flight test ReadiJet 100% renewable biojet fuel
September 13, 2012
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| Overview of the ReadiJet process. Click to enlarge. |
Applied Research Associates (ARA) and Chevron Lummus Global (CLG) are partnering with the National Research Council of Canada (NRC), the US Air Force Research Laboratory (AFRL), and Agrisoma Biosciences Inc. to evaluate CLG and ARA’s 100% drop-in ReadiJet Fuel derived from Agrisoma Resonance feedstock.
The ReadiJet effort combines ARA’s CH PROCESS technology— a catalytic hydrothermolysis (CH) process to convert triglycerides (e.g., crop oils and animal fats) to non-ester biofuels or intermediates—with Chevron Lummus Global’s ISOCONVERSION process technology to create drop-in biofuels that will be ready to use at 100% levels in jet and diesel engines, eliminating the need for blending with petroleum-derived fuels. (Earlier post.)
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2013 Accord featuring first use of new Honda emissions aftertreatment catalyst and new technology to weld together steel and aluminum
September 06, 2012
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| The new catalyst enhances the performance of palladium, also allowing a reduction in rhodium use. Click to enlarge. |
The 2013 Honda Accord, due to go on sale in the US on 19 September, features the first use of a new Honda-developed catalyst which significantly reduces the precious metals required in catalysts for emissions aftertreatment. Honda will continue to adopt this catalyst sequentially to other models.
The 2013 Accord also features first use of a new technology for the continuous welding of the dissimilar metals of steel and aluminum. Honda applied this for the first time to the vehicle subframe, a key component of a vehicle body frame. Honda will expand application sequentially to other models after the Accord.
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IBN researchers develop new gold-copper-platinum core-shell electrocatalyst for fuel cells
August 24, 2012
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| An illustration of the new IBN nanocomposite material which is composed of gold-copper alloy atoms in the core and platinum atoms at the outer layer. Source: IBN. Click to enlarge. |
Researchers at the Institute of Bioengineering and Nanotechnology (IBN) in Singapore report the synthesis of core–shell AuCu@Pt nanoparticles exhibiting superior electrocatalytic activity and excellent stability towards the oxygen reduction reaction (ORR) in fuel cells. A paper on their work appears in the RSC journal Energy and Environmental Science.
A general challenge in fuel cell development involves improving the durability and electrocatalytic activity of platinum-based electrocatalysts, while reducing the loading of the expensive metal. Professor Jackie Y. Ying and colleagues discovered that by replacing the central part of the catalyst with gold and copper alloy and leaving just the outer layer in platinum, the new hybrid material can provide 5 times higher activity and much greater stability than the commercial platinum catalyst. With further optimization, it would be possible to further increase the material’s catalytic properties, they said.
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Consolidated bioprocessing company Aemetis licenses plant oil hydroprocessing technology from Chevron Lummus Global for renewable jet and diesel
August 22, 2012
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| Outline of the Biofuels ISOCONVERSION process. Source: ARA. Click to enlarge. |
Aemetis, Inc., originally known as AE Biofuels, an industrial biotechnology company producing renewable chemicals and advanced fuels using patented microbes and processes, has signed a license agreement with Chevron Lummus Global (CLG) for the use of the Biofuels ISOCONVERSION process for the production of 100% drop-in renewable jet fuel and diesel from plant oils.
The Biofuels ISOCONVERSION Process utilizes patented Catalytic Hydrothermolysis (CH) reactor technology, developed by Applied Research Associates (ARA). CH utilizes water to reduce hydrogen and catalyst consumption and quickly and inexpensively converts plant oils into stable intermediate oil products which are very similar to petroleum crude oil. The intermediate oils are then hydrotreated and deoxygenated using CLG’s ISOCONVERSION catalysts to produce drop-in jet fuel and diesel.
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SLAC-Stanford study suggests that tailored 3D nanostructures can enhance activity and stability of fuel cell catalysts
August 18, 2012
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| An example of a platinum island of optimized thickness and shape, containing a high number of very active sites (shown in yellow). The graph shows how the predicted catalytic activity (the black dots) decreases as such islands increase in width. (Image courtesy Daniel Friebel, et. al.) Click to enlarge. |
A study by researchers from two SLAC-Stanford joint institutes—the Stanford Institute for Materials and Energy Sciences (SIMES) and the SUNCAT Center for Interface Science and Catalysis—has found that engineering fuel cell catalysts with tailored 3D nanostructures—with increased occurrence of the most active sites—could strongly enhance catalyst stability and activity.
The results argue for adding three-dimensional nanostructuring as an additional catalyst design criterion and so provide insight into novel approaches to catalyst design that could result in less expensive catalysts for fuel cells. A paper on their work was recently published in the Journal of the American Chemical Society.
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New mixed-oxide catalysts shown as viable substitute for platinum catalysts for diesel exhaust aftertreatment
August 17, 2012
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| NO conversion versus ramp-up and ramp-down temperatures for MnCe-7:1 (●), SmMn2O5 (□), GdSrCeMn7O14.83 (■), and Pt (○). Credit: Science, Wang et al. Click to enlarge. |
Researchers at nano-material catalysts startup Nanostellar and colleagues at the University of Kentucky and Huazhong University of Science and Technology in China have shown that mixed-phase oxide materials based on Mn-mullite (Sm, Gd)Mn2O5 are an efficient substitute for the current commercial platinum (Pt)-based catalysts for the aftertreatment of diesel exhaust.
Under laboratory-simulated diesel exhaust conditions, this mixed-phase oxide material was superior to Pt in terms of cost, thermal durability, and catalytic activity for NO oxidation. The new material is active at temperatures as low as 120 °C with conversion maxima of ~45% higher than that achieved with Pt. A paper on their work is published in the journal Science.
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Researchers develop new highly efficient core-shell catalyst for methane oxidation; potential for reducing emissions from automotive engines
August 13, 2012
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| A representation of the newly developed catalyst on an aluminium oxide surface depicts the core-shell structure. Click to enlarge. |
Researchers from the University of Pennsylvania, along with collaborators from Italy and Spain, have designed new core-shell type catalysts inspired by the concepts of supramolecular chemistry that oxidize methane 30 times better than do currently available catalysts. (Supramolecular chemistry is an interdisciplinary field covering the chemical, physical and biological features of chemical species of higher complexity that are held together and organized by means of intermolecular (non-covalent) binding interactions.) A paper on the new catalysts developed by Cargnello et al. is published in the journal Science.
The new approach in catalyst structure is important for catalyst-assisted combustion in gas turbines fueled with natural gas, and may also help to address methane emissions in the automobile exhaust within the temperature range required for emission control, comments Dr. Robert J. Farrauto of Columbia University in a Perspective piece accompanying the report in Science.
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New hierarchical nanosheet zeolite catalysts could improve efficiences in fuel, chemical and pharmaceutical production
June 29, 2012
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| The research team used a unique process to encourage growth of ultra-thin zeolite nanosheets at 90-degree angles, similar to building a house of cards. Credit: U of Minn. Click to enlarge. |
An international team led by University of Minnesota chemical engineering and materials science professor Michael Tsapatsis reports in the journal Science on a prototype of a new catalyst made of orthogonally connected microporous zeolite nanosheets (earlier post). The new development could lead to major efficiencies and cost-savings in catalyst-dependent production of gasoline, plastics, biofuels, pharmaceuticals, and other chemicals.
The “house-of-cards” arrangement of the nanosheets creates a permanent network of 2- to 7-nanometer mesopores, which, along with the high external surface area and reduced micropore diffusion length, account for the higher reaction rates for bulky molecules relative to those of other mesoporous and conventional MFI zeolites. The structure improves efficiencies by giving molecules fast access to the catalysts where the chemical reactions occur.
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Winners of 2012 Presidential Green Chemistry Challenge
June 18, 2012
American Chemical Society (ACS) President Bassam Z. Shakhashiri, Ph.D., and Jim Jones, Acting Assistant Administrator for the Office of Chemical Safety and Pollution Prevention at the US Environmental Protection Agency (EPA), announced the winners of the 2012 Presidential Green Chemistry Challenge Awards.
The Presidential Green Chemistry Challenge was established to recognize and promote innovative chemical technologies that prevent pollution and have broad applicability in industry. The Challenge is sponsored by the EPA Office of Chemical Safety and Pollution Prevention in partnership with the ACS Green Chemistry Institute and other members of the chemical community. The awardees for 2012 are:
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PNNL team finds that use of an ionic liquid/aqueous solution boosts performance of nickel-based catalyst for hydrogen production more than 50-fold
June 16, 2012
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| Cyclic voltammograms of the catalytic system initially and after each of seven additions of 20 μL water shows how the catalyst picks up speed as water is added to the ionic liquid (more water equals taller, faster current). Credit: Pool et al. Click to enlarge. |
Researchers at the Center for Molecular Electrocatalysis at the US Department of Energy’s (DOE) Pacific Northwest National Laboratory (PNNL) have found that dissolving a nickel-based, hydrogenase-inspired catalyst in an ionic liquid/aqueous solution improves the observed catalytic rate of hydrogen production by more than a factor of 50, compared to the use of a traditional organic solvent.
In an open access paper published in the Proceedings of the National Academy of Sciences, they reported that their ionic liquid system showed a turnover frequency of 43,000–53,000 s−1 for hydrogen production at 25 °C when the mole fraction of water (χH2O is 0.72. The same catalyst in acetonitrile with added dimethylformamidium trifluoromethanesulfonate and water has a turnover frequency of 720 s−1.
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Researchers optimize production of high-quality transportation fuels from LDPE plastics
June 10, 2012
Researchers in Spain have obtained high-quality transportation fuels (gasoline with RON >80 and diesel with cetane number >70) from oil obtained by the thermal cracking of low-density polyethylene (LDPE) using a bifunctional catalyst comprising Ni (7 wt %) deposited on a hierarchical Beta zeolite (Ni/h-Beta). A paper on their work is published in the ACS journal Energy & Fuels.
LDPE—the first grade of polyethylene, discovered in 1933 in the course of fundamental research at Imperial Chemical Industries in England— is created by the high pressure polymerization of ethylene. LDPE (SPI resin code “4” for recycling) is currently mainly used in the packaging, construction and automotive sectors, which accounted for 80% of the global LDPE demand in 2010, according to a 2011 market research report.
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China team optimizes catalytic hydrogenation process to convert coal tar to gasoline and diesel
June 09, 2012
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| Flow diagram of coal tar hydrogenation process. Credit: ACS, Kan et al. Click to enlarge. |
Researchers in China report the production of gasoline and diesel from coal tar via an optimized catalytic hydrogenation using two serial fixed beds, the first with a hydrofining catalyst of MoNi/γ-Al2O3 and the second with a hydrocracking catalyst of WNiP/γ-Al2O3-USY. Their paper was published in the ACS journal Energy & Fuels.
Coal tars—highly viscous liquids—are byproduct of the carbonization of coal to produce metallurgical coke and/or natural gas. In 2010, China’s coke output reached 387.571 million tons, accounting for 61.6% of the world’s total, according to a 2011 market research report; 9.94 million tons of coal tar was further processed. The current downstream markets of coal tar mainly include coal tar deep-processing (phenol, anthracene, industrial naphthalin, and coal tar pitch), carbon black, substitutes for heavy oil and exportation. Among these applications in China, deep processing ranked first with 66.4% of the total consumption volume in 2009, followed by carbon black raw oil sharing 28.1% of the total.
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Carbon nanotube–graphene complexes show promise as low-cast, high-activity electrocatalysts for fuel cells or metal-air batteries
May 28, 2012
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| This drawing shows the damaged outer wall of a carbon nanotube with nanosized graphene pieces (white patches), which facilitate the formation of catalytic sites made of iron (yellow) and nitrogen (red) atoms. The catalyst reduces oxygen to water. Click to enlarge. |
A team of researchers has demonstrated the ability of “partially unzipped” carbon nanotubes to act as an oxygen reduction electrocatalyst in both acidic and alkaline solution. The work, led by Stanford University’s Dr. Hongjie Dai, and reported in the journal Nature Nanotechnology, could lead to lower-cost alternatives to platinum for use in fuel cells and metal-aire batteries.
In the new process, the outer walls of the few-walled carbon nanotubes are partially unzipped, creating nanoscale sheets of graphene attached to the inner tubes (carbon nanotube–graphene complexes). The graphene sheets contain extremely small amounts of iron originated from nanotube growth seeds, and nitrogen impurities, which facilitate the formation of catalytic sites and boost the activity of the catalyst.
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BNL Researchers develop low-cost, efficient, non-noble metal electrocatalyst to produce hydrogen from water
May 09, 2012
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| Details of the unexpected nanosheet structure of the nickel-molybdenum-nitride catalyst, seen here as dark, straight lines. Source: BNL. Click to enlarge. |
A team of researchers led by Dr. James Muckerman at the US Department of Energy’s (DOE) Brookhaven National Laboratory (BNL) have developed a new class of high-activity, low-cost, non-noble metal electrocatalyst that generates hydrogen gas from water. The carbon-supported nickel–molybdenum nitride (NiMoNx) catalyst has a nanoscale sheet structure comprising a few layers and an abundance of highly accessible reactive sites.
The novel form of catalytic nickel-molybdenum-nitride—described in a paper published in the journal Angewandte Chemie International Edition—surprised scientists with its high-performing nanosheet structure, introducing a new model for effective hydrogen catalysis.
