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  • richardmitnick 6:11 pm on August 8, 2014 Permalink | Reply
    Tags: , Catalyst technology,   

    From EMSL: “Improving catalysts” 

    EMSL
    Environmental Molecular Sciences Laboratory (EMSL)

    No Date
    No Writer Credit

    Better bimetallic catalysts for fuel and chemical industries

    The Science

    Nanocatalysts consisting of two metals can offer superior performance compared with those made up of only one metal, so they are widely used for industrial processes that generate fuels and chemicals from natural gas, coal or plant biomass. However, complex interactions between the two metals during catalytic reactions can lower catalytic efficiency. This study addresses this issue by directly observing the changes of platinum-cobalt nanoparticles in operating conditions. Such particles are used as catalysts to convert carbon dioxide and hydrogen into long-chain carbon fuels and are important to the operation of low-temperature fuel cells.

    cat
    No image credit

    The Impact

    The new insights on the transformations of multiple component catalysts will allow researchers to optimally design similar catalysts to improve their performance, extend their lifetime, and reduce their environmental impact. Moreover, this research could guide efforts to minimize the use of precious metal components such as platinum and therefore reduce the cost of catalysts and lead to a more economical product for consumers.

    Summary

    In a multi-national lab effort led by Haimei Zheng from Lawrence Berkeley National Laboratory, researchers from DOE’s Pacific Northwest National Laboratory and collaborators examined real-time changes in the atomic structure of nanoparticles consisting of platinum and cobalt during reactions with oxygen and hydrogen using environmental transmission electron microscopy (ETEM), a specialized instrument housed in the Quiet Wing at the Environmental Molecular Sciences Laboratory (EMSL), a DOE national scientific user facility. The work was supported by the Chemical Imaging Initiative at PNNL.

    During oxidation in an oxygen gas environment, cobalt migrated to the nanoparticle surface, where it formed a cobalt oxide film that covered the platinum. Within ten seconds, this oxide film broke apart to form distinct islands and created voids in the interior of the particle, which can impair catalyst performance. This process was reversed during reduction in a hydrogen gas environment, which caused the cobalt oxide patches to decrease and the cobalt to migrate back to the bulk of the particle. Reduction with hydrogen also caused a layer of platinum to form on the particle surface, which is expected to improve catalyst performance.

    These new insights into the atomic scale behavior of nanoparticles consisting of multiple metals in reactive environments pave the way for a deeper understanding of the properties of multi-component catalysts and will guide efforts to improve their performance. In particular, the findings can be used to design multi-component catalysts that do not form oxide islands on the nanoparticle surface, but rather retain the material with higher catalytic performance on the nanoparticle surface during catalytic reactions.

    Funding

    This research was supported by DOE’s Office of Science and the Office of Basic Energy Sciences’ Chemical Science Division, as well as the Chemical Imaging Initiative at PNNL through the

    Laboratory Directed Research and Development Programs at PNNL and LBNL.

    See the full article here.

    EMSL is a national scientific user facility that is funded and sponsored by DOE’s Office of Biological & Environmental Research. As a user facility, our scientific capabilities – people, instruments and facilities – are available for use by the global research community. We support BER’s mission to provide innovative solutions to the nation’s environmental and energy production challenges in areas such as atmospheric aerosols, feedstocks, global carbon cycling, biogeochemistry, subsurface science and energy materials.

    A deep understanding of molecular-level processes is critical to gaining a predictive, systems-level understanding of the impacts of aerosols and terrestrial systems on climate change; making clean, affordable, abundant energy; and cleaning up our legacy wastes. Visit our Science page to learn how EMSL leads in these areas, through our Science Themes.

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  • richardmitnick 9:13 am on August 1, 2014 Permalink | Reply
    Tags: , , Catalyst technology,   

    From Brookhaven Lab: “Nanostructured Metal-Oxide Catalyst Efficiently Converts CO2 to Methanol” 

    Brookhaven Lab

    July 31, 2014
    Karen McNulty Walsh, (631) 344-8350 or Peter Genzer, (631) 344-3174printer iconPrint

    Highly reactive sites at interface of two nanoscale components could help overcome hurdle of using CO2 as a starting point in producing useful products

    people
    Dario Stacchiola and Kumudu Mudiyanselage make notes in the data log while Fang Xu (seated) and Jose Rodriguez view microscopic images of the catalyst and Ping Liu and Sanjaya Senanayake adjust the ambient-pressure scanning tunneling microscope. No image credit

    Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have discovered a new catalytic system for converting carbon dioxide (CO2) to methanol—a key commodity used to create a wide range of industrial chemicals and fuels. With significantly higher activity than other catalysts now in use, the new system could make it easier to get normally unreactive CO2 to participate in these reactions.

    “Developing an effective catalyst for synthesizing methanol from CO2 could greatly expand the use of this abundant gas as an economical feedstock,” said Brookhaven chemist Jose Rodriguez, who led the research. It’s even possible to imagine a future in which such catalysts help mitigate the accumulation of this greenhouse gas, by capturing CO2 emitted from methanol-powered combustion engines and fuel cells, and recycling it to synthesize new fuel.

    That future, of course, will be determined by a variety of factors, including economics. “Our basic research studies are focused on the science—the discovery of how such catalysts work, and the use of this knowledge to improve their activity and selectivity,” Rodriguez emphasized.

    The research team, which included scientists from Brookhaven, the University of Seville in Spain, and Central University of Venezuela, describes their results in the August 1, 2014, issue of the journal Science.

    New tools for discovery

    fu
    Fang Xu, a Stony Brook University PhD student working with the Brookhaven Lab team on studies to identify more effective catalysts for industrial processes, peers into the ambient-pressure scanning tunneling microscope used in these experiments.

    Because CO2 is normally such a reluctant participant in chemical reactions, interacting weakly with most catalysts, it’s also rather difficult to study. These studies required the use of newly developed in-situ (or on-site, meaning under reaction conditions) imaging and chemical “fingerprinting” techniques. These techniques allowed the scientists to peer into the dynamic evolution of a variety of catalysts as they operated in real time. The scientists also used computational modeling at the University of Seville and the Barcelona Supercomputing Center to provide a molecular description of the methanol synthesis mechanism.

    The team was particularly interested in exploring a catalyst composed of copper and ceria (cerium-oxide) nanoparticles, sometimes also mixed with titania. The scientists’ previous studies with such metal-oxide nanoparticle catalysts have demonstrated their exceptional reactivity in a variety of reactions. In those studies, the interfaces of the two types of nanoparticles turned out to be critical to the reactivity of the catalysts, with highly reactive sites forming at regions where the two phases meet.

    To explore the reactivity of such dual particle catalytic systems in converting CO2 to methanol, the scientists used spectroscopic techniques to investigate the interaction of CO2 with plain copper, plain cerium-oxide, and cerium-oxide/copper surfaces at a range of reaction temperatures and pressures. Chemical fingerprinting was combined with computational modeling to reveal the most probable progression of intermediates as the reaction from CO2 to methanol proceeded.

    These studies revealed that the metal component of the catalysts alone could not carry out all the chemical steps necessary for the production of methanol. The most effective binding and activation of CO2 occurred at the interfaces between metal and oxide nanoparticles in the cerium-oxide/copper catalytic system.

    “The key active sites for the chemical transformations involved atoms from the metal [copper] and oxide [ceria or ceria/titania] phases,” said Jesus Graciani, a chemist from the University of Seville and first author on the paper. The resulting catalyst converts CO2 to methanol more than a thousand times faster than plain copper particles, and almost 90 times faster than a common copper/zinc-oxide catalyst currently in industrial use.

    two
    Scanning tunneling microscope image of a cerium-oxide and copper catalyst (CeOx-Cu) used in the transformation of carbon dioxide (CO2) and hydrogen (H2) gases to methanol (CH3OH) and water (H2O). In the presence of hydrogen, the Ce4+ and Cu+1 are reduced to Ce3+ and Cu0 with a change in the structure of the catalyst surface.

    This study illustrates the substantial benefits that can be obtained by properly tuning the properties of a metal-oxide interface in catalysts for methanol synthesis.

    “It is a very interesting step, and appears to create a new strategy for the design of highly active catalysts for the synthesis of alcohols and related molecules,” said Brookhaven Lab Chemistry Department Chair Alex Harris.

    The work at Brookhaven Lab was supported by the DOE Office of Science. The studies performed at the University of Seville were funded by the Ministerio de Economía y Competitividad of Spain and the European Regional Development Fund. The Instituto de Tecnologia Venezolana para el Petroleo supported part of the work carried out at the Central University of Venezuela.

    Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

    See the full article, with video, here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 8:46 am on June 6, 2014 Permalink | Reply
    Tags: , , Catalyst technology, ,   

    From Brookhaven Lab: “Ionic Liquid Boosts Efficiency of CO2 Reduction Catalyst” 

    Brookhaven Lab

    June 6, 2014
    Karen McNulty Walsh

    Promising approach for converting abundant gas to building blocks for liquid fuels and other useful chemicals

    Wouldn’t it be nice to use solar- or wind-generated electricity to turn excess carbon dioxide—one of the gases trapping heat in Earth’s atmosphere—into fuels and other useful chemicals? The process would store up the intermittent solar or wind energy in a form that could be used when and where it was needed, including in transportation applications, all while getting rid of some greenhouse gas. The trick is to find the right catalysts to facilitate the conversion of CO2 with high activity and minimal energy input.

    two
    Yasuo Matsubara and David Grills

    One useful product of such CO2 reduction reactions is carbon monoxide (CO), a building block for making methanol and liquid hydrocarbons that could replace gasoline. So far, the catalysts tried for this reaction are often lacking in efficiency and/or specificity; either they take too much energy, are too slow, or make too wide a variety of products to be useful. Now a group of chemists at the U.S. Department of Energy’s Brookhaven National Laboratory reports a new approach: performing the electrochemical reaction in an ionic liquid, which acts as both the solvent and electrolyte.

    The process—described in a paper recently published in The Journal of Physical Chemistry Letters, published by the American Chemical Society (ACS)—was shown to boost both the energy efficiency and speed of the reaction for a well-known catalyst, with no loss of product selectivity, compared to the same reaction in a standard organic solvent solution. The paper was just selected as an ACS Editors’ Choice article. Only one such article is selected each day from the entire portfolio of ACS journals.

    Ionic liquids are salts made of positive and negative ions, similar to the sodium and chloride ions of table salt, but in liquid form at room temperature. Their blend of positive and negative charges makes them excellent conductors (electrolytes) and gives them unique properties, resulting in their recent emergence as superior alternatives to conventional organic solvents for many energy-related applications.

    Ionic liquids have previously shown some promise at improving the energy efficiency of the direct electrochemical reduction of CO2 at metal electrodes. The new work, led by Brookhaven Lab chemist David Grills and Yasuo Matsubara of the Japan Science and Technology Agency, is the first attempt to use ionic liquids to improve CO2 reduction using a homogeneous electrocatalyst—where both the reactants and catalyst are dissolved in a liquid. Homogeneous CO2 reduction catalysts are generally more selective in the products they produce.

    “Our experiment resulted in an improvement in both the energy efficiency and kinetics of the CO2 reduction process for the catalyst we studied, with no loss of product selectivity,” Grills said.

    The reason for the improvement, the scientists suspect, is a special interaction between one of the ionic liquid’s ions and an intermediate form of the catalyst that results in a lowering of the activation energy required for the reaction.

    The new approach will undoubtedly inspire a great deal of follow-up effort.

    “We expect that these initial results will open up new possibilities for studying ionic-liquid-enhanced CO2 reduction with a range of homogeneous catalysts and different types of ionic liquids,” said Matsubara.

    The work may even point the way to catalytic systems that can directly convert CO2 to other useful chemicals.

    Brookhaven’s role in this research was funded by the DOE Office of Science.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 11:55 am on April 23, 2014 Permalink | Reply
    Tags: , Catalyst technology, , ,   

    From PNNL Lab: “Halving hydrogen” 

    PNNL Lab

    April 23, 2014
    Mary Beckman

    – Like a hungry diner ripping open a dinner roll, a fuel cell catalyst that converts hydrogen into electricity must tear open a hydrogen molecule. Now researchers have captured a view of such a catalyst holding onto the two halves of its hydrogen feast. The view confirms previous hypotheses and provides insight into how to make the catalyst work better for alternative energy uses.

    cat
    Neutron crystallography shows this iron catalyst gripping two hydrogen atoms (red spheres). This arrangement allows an unusual dihydrogen bond to form between the hydrogen atoms (red dots).

    This study is the first time scientists have shown precisely where the hydrogen halves end up in the structure of a molecular catalyst that breaks down hydrogen, the team reported online April 22 in Angewandte Chemie International Edition. The design of this catalyst was inspired by the innards of a natural protein called a hydrogenase enzyme.
    “The catalyst shows us what likely happens in the natural hydrogenase system,” said Morris Bullock of the Department of Energy’s Pacific Northwest National Laboratory. “The catalyst is where the action is, but the natural enzyme has a huge protein surrounding the catalytic site. It would be hard to see what we have seen with our catalyst because of the complexity of the protein.”

    Ironing Out Expense

    Hydrogen-powered fuel cells offer an alternative to burning fossil fuels, which generates greenhouse gases. Molecular hydrogen — two hydrogen atoms linked by an energy-rich chemical bond — feeds a fuel cell. Generating electricity through chemical reactions, the fuel cell spits out water and power.

    If renewable power is used to store energy in molecular hydrogen, these fuel cells can be carbon-neutral. But fuel cells aren’t cheap enough for everyday use.
    To make fuel cells less expensive, researchers turned to natural hydrogenase enzymes for inspiration. These enzymes break hydrogen for energy in the same way a fuel cell would. But while conventional fuel cell catalysts require expensive platinum, natural enzymes use cheap iron or nickel at their core.
    Researchers have been designing catalysts inspired by hydrogenase cores and testing them. In this work, an important step in breaking a hydrogen molecule so the bond’s energy can be captured as electricity is to break the bond unevenly. Instead of producing two equal hydrogen atoms, this catalyst must produce a positively charged proton and a negatively charged hydride.

    The physical shape of a catalyst — along with electrochemical information — can reveal how it does that. So far, scientists have determined the overall structure of catalysts with cheap metals using X-ray crystallography, but hydrogen atoms can’t be located accurately using X-rays. Based on chemistry and X-ray methods, researchers have a best guess for the position of hydrogen atoms, but imagination is no substitute for reality.

    Bullock, Tianbiao “Leo” Liu and their colleagues at the Center for Molecular Electrocatalysis at PNNL, one of DOE’s Energy Frontier Research Centers, collaborated with scientists at the Spallation Neutron Source at Oak Ridge National Laboratory in Tennessee to find the lurking proton and hydride. Using a beam of neutrons like a flashlight allows researchers to pinpoint the nucleus of atoms that form the backbone architecture of their iron-based catalyst.

    Bonding Jamboree

    To use their iron-based catalyst in neutron crystallography, the team had to modify it chemically so it would react with the hydrogen molecule in just the right way. Neutron crystallography also requires larger crystals as starting material compared to X-ray crystallography.

    “We were designing a molecule that represented an intermediate in the chemical reaction, and it required special experimental techniques,” Liu said. “It took more than six months to find the right conditions to grow large single crystals suitable for neutron diffraction. And another six months to pinpoint the position of the split H2 molecule.”

    Crystallizing their catalyst of interest into a nugget almost 40 times the size needed for X-rays, the team succeeded in determining the structure of the iron-based catalyst.
    The structure, they found, confirmed theories based on chemical analyses. For example, the barbell-shaped hydrogen molecule snuggles into the catalyst core. On being split, the negatively charged hydride attaches to the iron at the center of the catalyst; meanwhile, the positively charged proton attaches to a nitrogen atom across the catalytic core. The researchers expected this set-up, but no one had accurately characterized it in an actual structure before.

    In this form, the hydride and proton form a type of bond uncommonly seen by scientists — a dihydrogen bond. The energy-rich chemical bond between two hydrogen atoms in a molecule is called a covalent bond and is very strong. Another bond called a “hydrogen bond” is a weak one formed between a slightly positive hydrogen and another, slightly negative atom.
    Hydrogen bonds stabilize the structure of molecules by tacking down chains as they fold over within a molecule or between two independent molecules. Hydrogen bonds are also key to water surface tension, ice’s ability to float and even a snowflake’s shape.

    The dihydrogen bond seen in the structure is much stronger than a single hydrogen bond. Measuring the distance between atoms reveals how tight the bond is. The team found that the dihydrogen bond was much shorter than typical hydrogen bonds but longer than typical covalent bonds. In fact, the dihydrogen bond is the shortest of its type so far identified, the researchers report.

    This unusually strong dihydrogen bond likely plays into how well the catalyst balances tearing the hydrogen molecule apart and putting it back together. This balance allows the catalyst to work efficiently.

    “We’re not too far from acceptable with its efficiency,” said Bullock. “Now we just want to make it a little more efficient and faster.”

    This work was supported by the Department of Energy Office of Science.

    See the full article here.

    Pacific Northwest National Laboratory (PNNL) is one of the United States Department of Energy National Laboratories, managed by the Department of Energy’s Office of Science. The main campus of the laboratory is in Richland, Washington.

    PNNL scientists conduct basic and applied research and development to strengthen U.S. scientific foundations for fundamental research and innovation; prevent and counter acts of terrorism through applied research in information analysis, cyber security, and the nonproliferation of weapons of mass destruction; increase the U.S. energy capacity and reduce dependence on imported oil; and reduce the effects of human activity on the environment. PNNL has been operated by Battelle Memorial Institute since 1965.

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  • richardmitnick 7:38 pm on March 3, 2014 Permalink | Reply
    Tags: , Catalyst technology, ,   

    From SLAC: “Scientists Say New Catalyst Could Lead to Clean, Low-Cost Methanol Production” 

    Created by scientists from Stanford, SLAC and Denmark, the new nickel-gallium catalyst converts carbon dioxide emissions into an important industrial chemical and potential fuel

    March 3, 2014
    Mark Shwartz, Precourt Institute for Energy, Stanford University

    An international research team has discovered a potentially clean, low-cost way to convert carbon dioxide into methanol, a key ingredient in the production of plastics, adhesives and solvents, and a promising fuel for transportation.

    Scientists from Stanford University, SLAC National Accelerator Laboratory and the Technical University of Denmark combined theory and experimentation to identify a new nickel-gallium catalyst that converts hydrogen and carbon dioxide into methanol with fewer side-products than the conventional catalyst. The results are published in the March 2 online edition of the journal Nature Chemistry.

    “Methanol is processed in huge factories at very high pressures using hydrogen, carbon dioxide and carbon monoxide from natural gas,” said study lead author Felix Studt, a staff scientist at SLAC. “We are looking for materials than can make methanol from clean sources, such as sunshine, under low-pressure conditions, while generating low amounts of carbon monoxide.”

    The ultimate goal is to develop a large-scale manufacturing process that is nonpolluting and carbon neutral using clean hydrogen, the authors said.

    “Imagine if you could synthesize methanol using hydrogen from renewable sources, such as water split by sunlight, and carbon dioxide captured from power plants and other industrial smokestacks,” said co-author Jens Nørskov, a professor of chemical engineering at Stanford. “Eventually we would also like to make higher alcohols, such as ethanol and propanol, which, unlike methanol, can be directly added to gasoline today.”
    Industrial methanol

    Worldwide, about 65 million metric tons of methanol are produced each year for use in the manufacture of paints, polymers, glues and biofuels. In a typical methanol plant, natural gas and water are converted to synthesis gas (syngas), which consists of carbon monoxide, carbon dioxide and hydrogen. The syngas is then converted into methanol in a high-pressure process using a catalyst made of copper, zinc and aluminum.

    “We spent a lot of time studying methanol synthesis and the industrial process,” Studt said. “It took us about three years to figure out how the process works and to identify the active sites on the copper-zinc-aluminum catalyst that synthesize methanol.”

    Once he and his colleagues understood methanol synthesis at the molecular level, they began the hunt for a new catalyst capable of synthesizing methanol at low pressures using only hydrogen and carbon dioxide. Instead of testing a variety of compounds in the lab, Studt searched for promising catalysts in a massive computerized database that he and co-author Frank Abild-Pedersen developed at SLAC.

    “The technique is known as computational materials design,” explained Nørskov, the director of the SUNCAT Center for Interface Science and Catalysis at Stanford and SLAC. “You get ideas for new functional materials based entirely on computer calculations. There is no trial-and-error in the lab first. You use your insight and enormous computer power to identify new and interesting materials, which can then be tested experimentally.”

    image
    Artist’s rendering of the nickel-gallium active site, which synthesizes hydrogen and carbon dioxide into methanol. Nickel atoms are light grey, gallium atoms are dark grey, and oxygen atoms are red. (Jens Hummelshoj/SLAC)

    Studt compared the copper-zinc-aluminum catalyst with thousands of other materials in the database. The most promising candidate turned out to be a little-known compound called nickel-gallium.

    “Once we got the name of the compound out of the computer, someone still had to test it,” Nørskov said. “So we had to have a good experimental partner.”

    Nørskov turned to a research group at the Technical University of Denmark led by Ib Chorkendorff, a co-author of the research paper. First, the Danish team carried out the task of synthesizing nickel and gallium into a solid catalyst. Then the scientists conducted a series of experiments to see if the new catalyst could actually produce methanol at ordinary room pressure.

    The lab tests confirmed that the computer had made the right choice. At high temperatures, nickel-gallium produced more methanol than the conventional copper-zinc-aluminum catalyst, and considerably less of the carbon monoxide byproduct.

    “You want to make methanol, not carbon monoxide,” Chorkendorff said. “You also want a catalyst that’s stable and doesn’t decompose. The lab tests showed that nickel-gallium is, in fact, a very stable solid.”

    While these results show promise, a great deal of work lies ahead. “We’d like to make the catalyst a little more clean,” Chorkendorff added. “If it contains just a few nanoparticles of pure nickel, the output drops quite a bit, because pure nickel is lousy at synthesizing methanol. In fact, it makes all sorts of chemical byproducts that you don’t want.”

    Nickel is relatively abundant, and gallium, although more expensive, is widely used in the electronics industry. This suggests that the new catalyst could eventually be scaled up for industrial use, according to the authors. But to make methanol synthesis a truly carbon-neutral process will require overcoming many additional hurdles, they noted.

    Other co-authors of the study are Jens Hummelshøj of SLAC; and Irek Sharafutdinov, Christian Elkjaer and Søren Dahl of the Technical University of Denmark.

    The research was supported by the U.S. Department of Energy, the Danish National Research Foundation and the Danish Ministry of Science, Technology and Innovation.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 4:07 pm on August 13, 2013 Permalink | Reply
    Tags: , Catalyst technology,   

    From PNNL Lab: “New Catalyst Dives into Water to Produce Hydrogen” 

    August 2013
    Suraiya Farukhi
    Web Publishing

    Earth-abundant metal at heart of material that creates 170,000 molecules a second

    Results:Few catalysts are energy efficient, highly active, stable, and operate in water, but a nickel-based catalyst designed at the Center for Molecular Electrocatalysis at Pacific Northwest National Laboratory quickly produces hydrogen molecules in solutions with 75 percent water. This catalyst contains tailored relays that allow the catalyst to quickly shuttle protons from the solution to the heart of the catalyst, where they are added to electrons. The catalyst is known to be energy efficient, stable and highly active. With the modified design, it now operates in water, producing up to 170,000 hydrogen molecules per second. The study on this catalyst was highlighted as a hot article in Chemical Communications.

    ‘We’ve moved from pure organic solvents to solutions with increasing amounts of water,’ said Dr. Monte Helm, Deputy Director of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center. ‘We found that our catalyst performed better with water than in an organic solvent alone.’

    warerbug
    Few catalysts are energy efficient, highly active, stable, and able to operate in water; however, a redesigned nickel-based catalyst quickly and efficiently turns protons and electrons into hydrogen. One day, power generated by solar farms and wind turbines could be used to drive this transformation. This catalyst works in solutions with 75 percent water. John Darmon at PNNL captured this research in an image that was selected for the journal’s cover.
    We report a synthetic nickel complex containing proton relays that catalyzes the production of hydrogen in aqueous acetonitrile with turnover frequencies of 750-170,000/s at experimentally determined overpotentials of 310-470 mV.

    Why It Matters: Solar power is not a large part of our nation’s energy grid, in part because of its intermittent nature and the challenges involved in storing the energy. One option is to combine the electrons generated with protons and create molecular hydrogen. The hydrogen stores the energy for later use. Catalysts are needed to drive this reaction, and this study answers a fundamental question about these catalysts by showing how to design proton relays that achieve fast, energy-efficient materials able to work in water.

    ‘We are getting closer to what we need for a real-world catalyst,’ said Dr. Morris Bullock, Director of the Center for Molecular Electrocatalysis.”

    See the full article here.

    Pacific Northwest National Laboratory (PNNL) is one of the United States Department of Energy National Laboratories, managed by the Department of Energy’s Office of Science. The main campus of the laboratory is in Richland, Washington.

    PNNL scientists conduct basic and applied research and development to strengthen U.S. scientific foundations for fundamental research and innovation; prevent and counter acts of terrorism through applied research in information analysis, cyber security, and the nonproliferation of weapons of mass destruction; increase the U.S. energy capacity and reduce dependence on imported oil; and reduce the effects of human activity on the environment. PNNL has been operated by Battelle Memorial Institute since 1965.

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  • richardmitnick 8:52 pm on July 18, 2013 Permalink | Reply
    Tags: , , Catalyst technology,   

    From Brookhaven Lab: “Researchers Help Show New Way to Study and Improve Catalytic Reactions” 

    Brookhaven Lab

    July 18, 2013
    Contacts: Justin Eure, (631) 344-2347 or Peter Genzer, (631) 344-3174

    [The following press release on advancing nanocatalyst structure and performance was issued by the University of Pennsylvania. Scientists Rosa Diaz and Eric Stach of Brookhaven National Laboratory's Center for Functional Nanomaterials (CFN) combined results from two electron microscopes to reveal crucial information on the size and configuration of the catalysts. The collaboration correlated the CFN structural analysis with reactivity tests to determine the active sites of the catalysts...

    University of Pennsylvania Media contact: Evan Lerner at elerner@upenn.edu or 215-573-6604]

    University of Pennsylvania leads collaboration to test catalyst structures and enhance nanotechnology performance and fabrication.

    Catalysts are everywhere. They make chemical reactions that normally occur at extremely high temperatures and pressures possible within factories, cars and the comparatively balmy conditions within the human body. Developing better catalysts, however, is mainly a hit-or-miss process.

    Now, a study by researchers at the University of Pennsylvania, the University of Trieste and Brookhaven National Laboratory has shown a way to precisely design the active elements of a certain class of catalysts, showing which parameters are most critical for improving performance.

    This highly controlled process could be a new paradigm for fine-tuning catalysts used in everything from making new materials to environmental remediation.

    study
    By precisely designing a series of nanocrystals with different sizes, shapes and compositions, researchers showed that the efficiency of certain catalysts depends on the interface between their two materials. (Image: Matteo Cargnello)

    The research is the result of a highly collaborative effort between the three institutions. It was led by Christopher Murray, a Penn Integrates Knowledge Professor with appointments in the Department of Chemistry in the School of Arts and Sciences and the Department of Materials Science and Engineering in the School of Engineering and Applied Science, and Matteo Cargnello, a postdoctoral fellow in Murray’s group. Cargnello was a graduate student in Paolo Fornasiero’s group at the University of Trieste when the research began and also worked with Raymond Gorte, professor in the Department of Chemical and Biomolecular Engineering, after coming to Penn. Penn graduate students Vicky Doan-Nguyen and Thomas R. Gordon, as well as Brookhaven’s Rosa Diaz and Eric Stach, also contributed to the study. It was published in the journal Science.

    Murray’s team set out to improve the process for designing a class of reaction-promoting materials known as supported catalysts. These catalysts are made of two different solid substances—one supporting the other—but existing techniques for fabricating them don’t provide much in the way of precisely controlling their parameters. Because of the lack of uniformity in conventional catalysts, it can be difficult to tell which aspects of their combination lead to better systems.

    ‘In putting together materials design, functional testing and state-of-the art-characterization tools, we’re looking to develop a feedback loop,’ Murray said. ‘Improving our understanding about the active components of these catalysts can tell us what to emphasize in future systems.'”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 10:26 am on June 21, 2013 Permalink | Reply
    Tags: , , Catalyst technology, ,   

    From Brookhaven Lab: “A Designer Enzyme for Alternative Energy” 

    Brookhaven Lab

    June 20, 2013
    Mona S. Rowe

    “Imagine pulling energy out of thin air. Yi Lu and his colleagues are on that path, in a quest to find alternatives to fossil fuels. The team has designed an enzyme that can harvest the energy of atmospheric oxygen with high efficiency and long life. Their work is a big step in custom designing artificial enzymes for potential applications in alternative energy.

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    Ribbon diagram showing introduction of histadine and tyrosine residues into myoglobin, resulting in enzymes that reduce oxygen (O2)to water (H2O) with more than 1,000 turnovers and minimal release of reactive oxygen species. No image credit

    ‘Oxygen in air is abundant and cheap. Yet converting it to useful energy requires catalysts with high efficiency and stability,’ said Lu, a professor at the University of Illinois. He explained that nature’s catalysts are among the most efficient, certainly better than most fuel-cell catalysts of today. A typical ‘native’ catalyst is the enzyme heme carbon oxidase, or HCO. But HCOs are too big, too expensive and too unstable for practical applications.

    ‘We have designed an enzyme that is much smaller, cheaper and more stable than the native enzymes,’ said Lu.

    In brief, they introduced one tyrosine and two histidine residues into myoglobin, which yielded an enzyme that catalyzed the reduction of oxygen to water with minimal release of reactive oxygen species and more than 1,000 turnovers – the number of times an enzyme can catalyze the same reaction over and over. Reactive oxygen species are incomplete intermediates for the oxygen reduction; they not only decrease the efficiency of the energy-conversion reaction, but also damage fuel-cell components.

    According to Lu, designing enzymes, especially ones such as theirs that contain metal ions, is a real challenge. Most designed enzymes have relatively low turnovers and efficiency, making them difficult to use for applications. The researchers demonstrated the feasibility of designing enzymes with both high turnovers and efficiency.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 5:14 pm on April 10, 2013 Permalink | Reply
    Tags: , , Catalyst technology, ,   

    From Berkeley Lab: “…Black Nanoparticles Could Play Key Role in Clean Energy Photocatalysis” 


    Berkeley Lab

    “A unique atomic-scale engineering technique for turning low-efficiency photocatalytic “white” nanoparticles of titanium dioxide into high-efficiency “black” nanoparticles could be the key to clean energy technologies based on hydrogen.

    Samuel Mao, a scientist who holds joint appointments with Berkeley Lab’s Environmental Energy Technologies Division and the University of California at Berkeley, leads the development of a technique for engineering disorder into the nanocrystalline structure of the semiconductor titanium dioxide. This turns the naturally white crystals black in color, a sign that the crystals are now able to absorb infrared as well as visible and ultraviolet light. The expanded absorption spectrum substantially improves the efficiency with which black titanium dioxide can use sunlight to split water molecules for the production of hydrogen.

    swm
    Berkeley Lab’s Samuel Mao used disorder engineering to transform titanium nanocrystals into highly efficient solar hydrogen photocatalysts, a transformation marked by turning the crystals from white to black. (Photo by Roy Kaltschmidt)

    ‘We have demonstrated that black titanium dioxide nanoparticles are capable of generating hydrogen through solar-driven photocatalytic reactions with a record-high efficiency,’ Mao said in a talk at the American Chemical Society (ACS)’s national meeting in New Orleans.

    ‘The synthesis of black titanium dioxide nanoparticles was based on a hydrogenation process in which white titanium dioxide nanocrystals were subjected to high pressure hydrogen gas,’ said Mao. ‘The unique disordered structure creates a photocatalyst that is both durable and efficient, and gives titanium dioxide, one of the most-studied of all oxide materials, a renewed potential.’”

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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  • richardmitnick 3:30 pm on February 17, 2013 Permalink | Reply
    Tags: , Catalyst technology,   

    From PNNL Lab: “Synthetic molecule first electricity-making catalyst to use iron to split hydrogen gas” 

    February 17, 2013
    Mary Beckman

    To make fuel cells more economical, engineers want a fast and efficient iron-based molecule that splits hydrogen gas to make electricity. Online Feb. 17 at Nature Chemistry, researchers report such a catalyst. It is the first iron-based catalyst that converts hydrogen directly to electricity. The result moves chemists and engineers one step closer to widely affordable fuel cells.

    graph
    Burning hydrogen in a fuel cell generates an electrical current. A new iron-based catalyst might help make those fuel cells less expensive.

    ‘A drawback with today’s fuel cells is that the platinum they use is more than a thousand times more expensive than iron,’ said chemist R. Morris Bullock, who leads the research at the Department of Energy’s Pacific Northwest National Laboratory.

    His team at the Center for Molecular Electrocatalysis has been developing catalysts that use cheaper metals such as nickel and iron. The one they report here can split hydrogen as fast as two molecules per second with an efficiency approaching those of commercial catalysts. The center is one of 46 Energy Frontier Research Centers established by the DOE Office of Science across the nation in 2009 to accelerate basic research in energy.

    Pacific Northwest National Laboratory (PNNL) is one of the United States Department of Energy National Laboratories, managed by the Department of Energy’s Office of Science. The main campus of the laboratory is in Richland, Washington.”

    See the full article here.

    PNNL scientists conduct basic and applied research and development to strengthen U.S. scientific foundations for fundamental research and innovation; prevent and counter acts of terrorism through applied research in information analysis, cyber security, and the nonproliferation of weapons of mass destruction; increase the U.S. energy capacity and reduce dependence on imported oil; and reduce the effects of human activity on the environment. PNNL has been operated by Battelle Memorial Institute since 1965.

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