[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.]
Stanford team reports new low-cost, non-precious metal catalyst for water splitting with performance close to platinum
August 22, 2014
|Structure of the NiO/Ni-CNT hybrid. Blue = nickel, green = nickel oxide. Credit: Gong et al. Click to enlarge.|
Researchers at Stanford University, with colleagues at Oak Ridge National Laboratory and other institutions, have developed a nickel-based electrocatalyst for low-cost water-splitting for hydrogen production with performance close to that of much more expensive commercial platinum electrocatalysts.
As described in their paper in Nature Communications, the catalyst comprises nanoscale nickel oxide/nickel heterostructures formed on carbon nanotube sidewalls (NiO/Ni-CNT nano-hybrids). The researchers were able to make the electrocatalysts active enough to split water at room temperature with a single 1.5-volt battery, said Hongjie Dai, a professor of chemistry at Stanford. This marked the first time anyone has used non-precious metal catalysts to split water at a voltage that low, he added.
PNNL study uncovers role of water in forming impurity in bio-oil upgrading; insight into fundamentals of biofuel catalysis
August 21, 2014
In working to elucidate the chemistry of hydrodeoxygenation (HDO) for the catalytic upgrading of pyrolytic bio-oil to fuel-grade products, researchers at Pacific Northwest National Laboratory (PNNL) have discovered that water in the conversion process helps form an impurity which, in turn, slows down key chemical reactions. Results of the study, which was reported in the Journal of the American Chemical Society, can help improve processes that produce biofuels from plants.
The study examines the conversion of bio-oil, produced from biomass such as wood chips or grasses, into transportation fuels. Researchers used density functional theory (DFT)-based ab initio molecular dynamics calculations to provide a detailed atomic-level understanding of how the hydrogenation reactions are influenced by the presence of water and also by the nature of the hydrogenating metal. The results of the study apply not only to water but to related liquids in bio-oil such as alcohols and certain acids.
OCM company Siluria pulls in $30M in D round led by Saudi Aramco; methane to fuels and chemicals
August 20, 2014
Siluria Technologies, a pioneer in the commercialization of an oxidative coupling of methane (OCM) technology to produce ethylene from natural gas (earlier post), announced the initial close of its Series D financing round. The round was led by Saudi Aramco Energy Ventures (SAEV), the venture investment subsidiary of Saudi Aramco and included additional investments by all of the major existing investors in Siluria. The total raise for this initial close of the Series D financing was $30 million.
With this initial Series D financing, Siluria has raised just under $100 million since its inception. Siluria is currently in discussions with additional strategic and financial investors to complete a total Series D financing of approximately $50 million.
New palladium oxalate hydrodeoxygenation catalyst for production of drop-in paraffinic biofuels
August 17, 2014
Researchers in Malaysia and Oman have developed a novel palladium oxalate catalyst supported on zeolite A (PdOx/ Zeol) with increased acidity for the hydrodeoxygenation and isomerization of bio-feedstocks into paraffinic (drop-in) biofuels. In a paper in the ACS journal Energy & Fuel, they report the hydrodeoxygenation (HDO) of stearic acid (SA) (one of the most common saturated fatty acids found in nature following palmitic acid) into paraffinic biofuel.
Their best observed conditions for the process were 360 °C, 20 bar, 100 mL/min, and 25 mg to achieve 92% biofuel production from 35 g SA. The biofuel product distribution showed 71% n-C18H38, 18% iso-C18H38, and 3% C17H36.
Molecular shuttle speeds up hydrogen production by the photocatalytic splitting of water
August 15, 2014
In their latest experiments with semiconductor nanocrystals as light absorbers, physicists led by Professor Jochen Feldmann (Ludwig-Maximilians-Universität München, LMU Munich), in collaboration with a team of chemists under the direction of Professor Andrey Rogach (City University of Hong Kong), have succeeded in significantly increasing the yield of hydrogen produced by the photocatalytic splitting of water.
The crucial innovation, reported in the latest issue of the journal Nature Materials, is the use of a so-called molecular shuttle to markedly improve the mobility of charge carriers in their reaction system.
Copper foam catalyst yields different product slate from CO2 than smooth electrodes; importance of catalyst architecture
August 13, 2014
A catalyst made from a foamy form of copper has different electrochemical properties from catalysts made with smooth copper in reactions involving carbon dioxide, according to a new study by a team from Brown University. The research, reported in the journal ACS Catalysis, suggests that copper foams could provide a new way of converting excess CO2 into useful industrial chemicals.
The researchers showed that the electrochemical reduction of CO2 at copper foams yields formic acid at a lower onset potential with faradaic efficiencies that are 10−20% higher than other reported values. In comparison to smooth copper electrodes, the faradaic efficiencies of CO, methane, and ethylene are reduced significantly, whereas C2 and C3 products such as ethane and propylene are produced in small but detectable quantities—overall, a very different product outcome than obtained from planar electrodes.
RIKEN researchers develop bio-inspired catalyst that splits water at neutral pH
August 09, 2014
Plants use photosynthesis to convert carbon dioxide and water into sugars and oxygen. The process starts in a cluster of manganese, calcium and oxygen atoms at the heart of a protein complex called photosystem II, which splits water to form oxygen gas, protons and electrons.
Numerous researchers have attempted to develop synthetic catalysts that mimic this cluster, using light or electricity to convert water into fuels such as hydrogen gas. Unlike plants, however, these artificial catalysts can only split alkaline water, which makes the process less sustainable. Now, researchers at the RIKEN Center for Sustainable Resource Science in Japan have developed a manganese oxide-based catalyst system that can split water efficiently at neutral pH. They report on their work in an open access paper in the journal Nature Communications.
UC Riverside team develops new high efficiency method for conversion of biomass to biofuels
August 04, 2014
|Overview of the process. Cai et al. (2014) Click to enlarge.|
A team of researchers, led by Professor Charles E. Wyman, the Ford Motor Company Chair in Environmental Engineering at the University of California, Riverside’s Bourns College of Engineering, has developed a versatile, relatively non-toxic, and efficient way to convert lignocellulosic biomass into biofuels and chemicals.
The method couples the use of a metal halide selective catalyst with a highly tunable co-solvent—renewable tetrahydrofuran (THF)—to enhance co-production of the fuel precursors furfural and 5-HMF from biomass in a single-phase reaction strategy capable of integrating biomass deconstruction with catalytic dehydration of sugars. Those fuel precursors can then be converted into ethanol, chemicals or drop-in fuels.
New catalytic system for conversion of CO2 to methanol shows much higher activity than others now in use
August 01, 2014
Scientists at the US Department of Energy’s (DOE) Brookhaven National Laboratory, with colleagues from the University of Seville (Spain) and Universidad Central de Venezuela, have discovered a new, highly active catalytic system for converting carbon dioxide to methanol.
The pure metals and bimetallic systems used for the chemical activation of CO2 usually have low catalytic activity; the new system exhibits significantly higher activity than other catalysts now in use. The new catalyst system 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.
New catalyst improves conversion of CO2 to syngas
July 30, 2014
Researchers from the University of Illinois at Chicago (UIC) have identified molybdenum disulfide as a promising cost-effective substitute for noble metal catalysts for the electrochemical reduction of carbon dioxide. A paper on their work is published in the journal Nature Communications.
While noble metals such as gold and silver are able to reduce carbon dioxide at moderate rates and low overpotentials, their cost is a challenge to the development of inexpensive systems with an efficient CO2 reduction capability. Amin Salehi-Khojin, UIC professor of mechanical and industrial engineering, and his colleagues developed a novel two-step catalytic process for CO2reduction that uses molybdenum disulfide and an ionic liquid. The new catalyst improves efficiency and lowers cost.
New one-pot process for conversion of cellulose to n-hexane, a gasoline component
June 26, 2014
|One-pot process for conversion of cellulose to hexane, a gasoline component. Credit: ACS, Liu et al. Click to enlarge.|
Researchers at Tohoku University in Japan have developed a one-pot process to convert cellulose to n-hexane in the presence of hydrogen gas. According to the US Environmental Protection Agency (EPA), unleaded gasoline contains about 11.6% n-hexane.
In a paper in the journal ACS Sustainable Chemistry & Engineering, the Tohuku team reports achieving a yield of n-hexane of 83% from ball-milled cellulose and 78% from microcrystalline cellulose. Even using a high weight ratio of cellulose to water (1:1), a 71% yield of n-hexane could be obtained from ball-milled cellulose.
DOE awards $100M in 2nd funding round for 32 Energy Frontier Research Centers
June 24, 2014
The US Department of Energy (DOE) is awarding $100 million in the second round of funding for Energy Frontier Research Centers (EFRCs); research supported by this initiative will enable fundamental advances in energy production, storage, and use.
The 32 projects receiving funding were competitively selected from more than 200 proposals. Ten of these projects are new while the rest received renewed funding based both on their achievements to date and the quality of their proposals for future research.
Washington State/Boeing SOFC shows promise for aviation and automotive applications
June 17, 2014
|MoO2-based SOFC using a fuel mixture consisting of n-dodecane, CO2 and air. Kwon 2013. Click to enlarge.|
Researchers at Washington State University, with colleagues at Kyung Hee University and Boeing Commercial Airplanes, have been developing liquid hydrocarbon/oxygenated hydrocarbon-fueled solid oxide fuel cells (SOFCs) for aviation (the “more electric” airplane) and other transportation applications, such as in cars. These fuel cells first internally—i.e., no external reformer—reform a complex liquid hydrocarbon fuel into carbon fragments and hydrogen, which are then electrochemically oxidized to produce electrical energy without external fuel processors. The SOFCs feature a MoO2 (molybdenum dioxide) anode with an interconnecting network of pores that exhibit excellent ion- and electron-transfer properties.
In a new paper in the journal Energy Technology, the team reports that this novel fuel cell, when directly fueled with a jet-A fuel surrogate (an n-dodecane fuel mixture), generated an initial maximum power density of 3 W cm-2 at 750 °C and maintained this high initial activity over 24 h with no coking. The addition of 500 ppm of sulfur into the fuel stream did not deactivate the cell.
Ames Lab creates multifunctional nanoparticles for cheaper, cleaner renewable diesel
May 13, 2014
Researchers at the US Department of Energy’s Ames Laboratory have developed bi-functional nanoparticles that perform two processing functions at once for the production of renewable diesel via the hydrogenation of oils from renewable feedstocks such as algae.
Iron nanoparticles supported on mesoporous silica nanoparticles (Fe-MSN) catalyze the hydrotreatment of fatty acids with high selectivity for hydrodeoxygenation over decarbonylation and hydrocracking. The selectivity is also affected by the pretreatment of Fe-MSN; the more reduced the catalyst the higher the yield of hydrodeoxygenation product. Fe-MSN catalyzes the conversion of crude microalgal oil into diesel-range hydrocarbons.
Researchers use neutron crystallography to show outcome of hydrogen cleavage by catalyst; helping to build better fuel cell catalyst
April 24, 2014
|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). Source: Liu et al. Click to enlarge.|
Using neutron crystallography, researchers at Pacific Northwest National Laboratory (PNNL) and their colleagues at Oak Ridge National Laboratory (ORNL) have shown for the first time precisely where the hydrogen halves end up in the structure of a molecular catalyst—an iron hydrogenase inspired by a natural hydrogenase enzyme—that breaks down hydrogen. A paper on their study is published in Angewandte Chemie International Edition.
The view confirms previous hypotheses and provides insight into how to make the catalyst work better for energy uses—i.e., for fuel cells—as an alternative to platinum.
Stanford researchers develop copper-based catalyst that produces ethanol from CO at room temperature; potential for closed-loop CO2-to-fuel process
April 11, 2014
Researchers at Stanford University have developed a nanocrystalline copper material that produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (–0.25 volts to –0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline water.
The material’s selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity, the team suggests in their paper published in the journal Nature. Ultimately, this might enable a closed-loop, emissions free CO2-to-fuel process.
DOE awards $17M to FY 2014 SBIR Phase II projects; includes Si/graphene anodes, motor windings, exhaust treatments
March 31, 2014
The US DOE recently awarded $17 million to 17 FY 2014 Small Business Innovation Research (SBIR) Phase II projects to further develop Phase I projects and to produce a prototype or equivalent within two years. The selected 17 awards represent the best of nearly 1,000 ideas submitted for the FY 2012/13 Broad Based Topic Solicitation, DOE said.
The selected projects include 6 vehicle-related technologies and 2 hydrogen and fuel cell technologies, as well as new hydropower, heat pump, solar and manufacturing technologies. Vehicle technologies span a range from new Si/graphene Li-ion anode materials and composites for motor windings to diesel aftertreatment and advanced lubricants. Selected vehicle and hydrogen technology projects are:
MIT Energy Initiative announces 2014 seed grant awards
March 30, 2014
The MIT Energy Initiative (MITEI) announced its latest round of seed grants to support early-stage innovative energy projects. A total of more than $1.6 million was awarded to 11 projects, each lasting up to two years. With this latest round, the MITEI Seed Fund Program has supported 129 early-stage research proposals, with total funding of about $15.8 million.
This year’s winners address a wide range of topics including new methods of designing and using catalysts; assessment of natural gas technologies; novel design concepts for batteries, energy harvesters, and capacitors; integrated photovoltaic–electrochemical devices to reduce CO2 for fuel production; and investigations into public opinion on various state energy policies.
Siluria Technologies unveils new development unit for liquid fuels from natural gas based on OCM and ETL technologies
March 21, 2014
Siluria Technologies, the developer of novel bio-templated catalysts for the economic direct conversion of methane (CH4) to ethylene (C2H4) (earlier post), unveiled a development unit for producing liquid fuels from natural gas based on Siluria’s proprietary oxidative coupling of methane (OCM) and ethylene-to-liquid (ETL) technologies.
Together, Siluria’s OCM and ETL technologies form a unique and efficient process for transforming methane into gasoline, diesel, jet fuel and other liquid fuels. Unlike the high-temperature, high-pressure cracking processes employed today to produce fuels and chemicals, Siluria’s process employs catalytic processes to create longer-chain, higher-value materials, thereby significantly reducing operating costs and capital.
Cellulosic fuels company KiOR reveals “substantial doubts” about its viability; funding needed by 1 April
March 19, 2014
In its Form 10-K (annual report) filed with the SEC on 17 March, cellulosic renewable fuels company KiOR said it has “substantial doubts about [its] ability to continue as a going concern”. Ongoing viability will require additional capital to provide additional liquidity. (Earlier post.)
On 16 March, the company received a $25-million investment commitment from Vinod Khosla (one of the company’s investors), conditioned on the achievement of certain performance milestones to be mutually agreed upon. Other than that commitment, however, Kior said it has no other near-term sources of financing. Kior said that if it is unsuccessful in finalizing definitive documentation with Khosla on or before 1 April 2014—i.e., in two weeks—it will not have adequate liquidity to fund operations and meet obligations (including debt payment obligations), and would not expect other sources of financing to be available.
UPM, Fortum and Valmet partnering to develop new catalytic pyrolysis technology for advanced lignocellulosic fuels
March 12, 2014
Fortum, UPM and Valmet have joined forces to develop a new catalytic pyrolysis technology to produce advanced high value lignocellulosic fuels, such as transportation fuels or higher value bio-liquids.
The five-year project is called LignoCat (lignocellulosic fuels by catalytic pyrolysis). The project is a natural continuation of the consortium’s earlier bio-oil project together with the VTT Technical Research Centre of Finland, commercializing integrated pyrolysis technology for production of sustainable bio-oil for replacement of heating oil in industrial use.
Vertimass licenses ORNL ethanol-to-hydrocarbon conversion technology; overcoming the blend wall with drop-in fuels
March 07, 2014
Vertimass LLC, a California-based start-up company, has licensed an Oak Ridge National Laboratory (ORNL) technology that directly converts ethanol under moderate conditions at one atmosphere without the use of hydrogen into a hydrocarbon blend-stock for use in transportation fuels.
The technology developed by ORNL’s Chaitanya Narula, Brian Davison and Associate Laboratory Director Martin Keller uses an inexpensive zeolite catalyst to transform ethanol into a blend-stock consisting of a mixture of C3 – C16 hydrocarbons containing paraffin, iso-parrafins, olefins, and aromatic compounds with a calculated motor octane number of 95. Fractional collection of the fuel product allows for the different fractions to be used as blend-stock for gasoline, diesel, or jet fuel.
MIT researchers devise simple catalytic system for fixation and conversion of CO2
March 05, 2014
Researchers at MIT have devised a simple, soluble metal oxide system to capture and transform CO2 into useful organic compounds. More work is needed to understand and to optimize the reaction, but this approach could offer an easy and inexpensive way to recapture some of the carbon dioxide emitted by vehicles and power plants, says Christopher Cummins, an MIT professor of chemistry and leader of the research team.
The new reaction, described in an open access paper in the RSC journal Chemical Science, transforms carbon dioxide into a negatively charged carbonate ion, which can then react with a silicon compound to produce formate, a common starting material for manufacturing useful organic compounds. This process relies on the simple molecular ion molybdate: an atom of the metal molybdenum bound to four atoms of oxygen.
New nickel-gallium catalyst could lead to low-cost, clean production of methanol; small-scale, low-pressure devices
March 03, 2014
Scientists from Stanford University, SLAC National Accelerator Laboratory and the Technical University of Denmark have identified a new nickel-gallium catalyst that converts hydrogen and carbon dioxide into methanol at ambient pressure and with fewer side-products than the conventional catalyst. The results are published in the journal Nature Chemistry.
The researchers identified the catalyst through a descriptor-based analysis of the process and the use of computational methods to identify Ni-Ga intermetallic compounds as stable candidates with good activity. After synthesizing and testing a series of catalysts, they found that Ni5Ga3 is particularly active and selective. Comparison with conventional Cu/ZnO/Al2O3 catalysts revealed the same or better methanol synthesis activity, as well as considerably lower production of CO.
Researchers at Berkeley and Argonne labs discover highly active new class of nanocatalysts for fuel cells; more efficient, lower cost
February 28, 2014
A team led by researchers at Berkeley and Argonne National Labs have discovered a new class of bimetallic nanocatalysts for fuel cells and water-alkali electrolyzers that are an order of magnitude higher in activity than the target set by the US Department of Energy (DOE) for 2017.
The new catalysts, hollow polyhedral nanoframes of platinum and nickel (Pt3Ni), feature a three-dimensional catalytic surface activity that makes them significantly more efficient and far less expensive than the best platinum catalysts used in today’s fuel cells and alkaline electrolyzers. This research, a collaborative effort between DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Argonne National Laboratory (ANL), is reported in the journal Science.
Computational first-principles approach identifies dozens of new platinum-group alloys
January 07, 2014
Researchers from Duke University, Brigham Young University, and Carnegie Mellon University have used high-throughput first-principles calculations to identify dozens of platinum-group alloys (binary systems of the platinum-group metals—PGMs—with the transition metals) that were previously unknown but that could prove beneficial in a wide range of applications.
The platinum-group metals (PGMs)—osmium, iridium, ruthenium, rhodium, platinum, and palladium—play essential roles in a wide variety of industrial applications. The primary application of PGMs is in catalysis, where they are core ingredients in the chemical, petroleum, and automotive industries. Although are essential, they are also very costly.
Converting glycerol from biodiesel production into bio-gasoline
December 16, 2013
A team at the University of Idaho has demonstrated that glycerol, a byproduct from biodiesel production, could be used as a substrate for producing drop-in gasoline-range biofuel. In a paper published in the ACS journal Energy & Fuels, Guanqun Luo and Armando G. McDonald describe their study of converting methanol (MTG) and a mixture of methanol and glycerol (MGTG) into gasoline-range hydrocarbons using a bench-top, fixed-bed microreactor.
The MTG- and MGTG-generated liquids showed a similar composition, mainly methylbenzenes, to regular gasoline, and composition changed as the reaction proceeded to favor heavier aromatics.
University of Houston team demonstrates new efficient solar water-splitting catalyst for hydrogen production
Researchers from the University of Houston (UH) have developed a cobalt(II) oxide (CoO) nanocrystalline catalyst that can carry out overall water splitting with a solar-to-hydrogen efficiency of around 5%. They report on their work in a paper in the journal Nature Nanotechnology.
Corresponding author Jiming Bao, an assistant professor in the Department of Electrical and Computer Engineering at UH, said photocatalytic water-splitting experiments have been tried since the 1970s, but this was the first to use cobalt oxide and the first to use neutral water under visible light at a high energy conversion efficiency without co-catalysts or sacrificial chemicals.
Axens, IFPEN and Michelin launch research partnership on synthetic rubber production channel using biomass; €52M over 8 years
November 11, 2013
|Overview of BioButterfly process steps. Click to enlarge.|
Axens, IFP Energies nouvelles (IFPEN) and Michelin have launched a plant chemistry research partnership that aims to develop and bring to market a process for producing bio-sourced butadiene, or bio-butadiene. Butadiene is a chemical intermediate derived from fossil resources that is used in the production of synthetic rubber. Some 60% of global output is for the tire industry.
In response to the need to find sustainable alternative sourcing channels for elastomers, the BioButterfly process will make it possible to produce innovative, more environmentally-friendly synthetic rubber. The bio-butadiene produced will support continued innovation in procuring high performance rubber for tires.
Battelle evaluating pilot-scale mobile catalytic pyrolysis unit to convert biomass to bio-oil
November 08, 2013
Battelle researchers have developed a mobile catalytic pyrolysis unit that converts biomass materials such as wood chips or agricultural waste into bio-oil. As currently configured, the Battelle-funded unit converts one ton of pine chips, shavings and sawdust into as much as 130 gallons of wet bio-oil per day.
The bio-oil then can be upgraded by hydrotreatment into a gas/diesel blend or jet fuel. Conversion of the bio-oil to an advanced biofuel is a key element of Battelle’s (earlier post)—and many others’—research. Testing of the bio-based gasoline alternative produced by Battelle suggests that it can be blended with existing gasoline and can help fuel producers meet their renewable fuel requirements.
JCAP researchers propose protocol for standardized evaluation of OER catalysts for solar-fuel systems
November 03, 2013
|Protocol for measuring the electrochemically active surface area, catalytic activity, stability, and Faradaic efficiency of heterogeneous electrocatalysts for OER. Credit: ACS, McCrory et al. Click to enlarge.|
Electro-catalytic water splitting to produce hydrogen and oxygen is a key element of solar-fuels devices; identifying efficient catalysts for the oxygen evolution reaction (OER) is critical to their realization. (The OER is efficiency-limiting for direct solar and electrolytic water splitting, rechargeable metal-air batteries, and regenerative fuel cells. Earlier post.) However, notes a team of researchers from the Joint Center for Artificial Photosynthesis at Caltech, current methods employed to evaluate oxygen-evolving catalysts are not standardized, making it difficult to compare the activity and stability of these materials.
To address this issue, the researchers are proposing a protocol to evaluate the activity, stability, and Faradaic efficiency of electro-deposited oxygen-evolving electrocatalysts. In particular, they focus on methods for determining electrochemically active surface area and measuring electrocatalytic activity and stability under conditions relevant to an integrated solar water-splitting device. A paper on their work is published in the Journal of the American Chemical Society.
UNIST team develops simple way to synthesize new metal-free electrocatalysts for oxygen reduction reaction (ORR)
October 29, 2013
|Overall Scheme for doped graphene oxide Copyright: UNIST. Click to enlarge.|
A research team from Ulsan National Institute of Science and Technology (UNIST), S. Korea, has developed a high-performance, stable and metal-free electrocatalyst for the oxygen reduction reaction (ORR). A paper on their work is published in the RSC journal Nanoscale.
The oxygen reduction reaction (ORR) is an important reaction in energy conversion systems such as fuel cells and metal–air batteries; electrocatalysts for oxygen reduction are critical components that may dramatically enhance the performance such systems. Carbon nanomaterials doped with heteroatoms are highly attractive materials for use as electrocatalysts by virtue of their excellent electrocatalytic activity, high conductivity, and large surface area.
Duke team develops new core-shell copper nanowire catalyst for efficient water oxidation for solar fuels
October 25, 2013
|A transparent film of copper nanowires was transformed into an electrocatalyst for water oxidation by electrodeposition of Ni or Co onto the surface of the nanowires. Chen et al. Click to enlarge.|
A team led by Benjamin J. Wiley at Duke University has introduced a new electrocatalyst for water oxidation consisting of a conductive network of core-shell nanowires that is just as efficient as conventional metal oxide films on indium tin oxide (ITO) and a great deal more transparent and robust. A paper on their work is published in the journal Angewandte Chemie.
Water oxidation (2H2O → O2 + 4e- + 4H+) is a key step for converting solar energy into chemical fuels. Nickel and cobalt oxides are attractive anode materials for the oxidation of water because they are readily available and demonstrate high catalytic activity. For use in photoelectric synthesis cells, in which chemical conversions are driven by light, the oxides are typically electrodeposited onto ITO substrates. ITO is used because of its high transmittance and low sheet resistance.
Researchers develop viable catalysts for reforming of heavy gas oil to hydrogen
October 14, 2013
One approach to delivering hydrogen for the stacks in fuel cell vehicles is via the on-board reforming of hydrocarbon fuels; such an approach obviates the need for on-board hydrogen gas storage technology and leverages the existing liquid fuels infrastructure. However, using more refined low-sulfur hydrocarbon fuels can add to the overall cost of the system. Less refined fuels—such as heavy gas oil—would be less expensive; however, the higher levels of sulfur in the fuels could prove problematic for catalysts.
Now, researchers in S. Korean and Japan have synthesized hollow fiber catalysts networked with perovskite nanoparticles for the production of hydrogen from heavy gas oil reforming, some of which showed high efficiency for H2 production with substantial durability under high concentrations of S, N, and aromatic compounds. Their findings are reported in an open access paper in the journal Scientific Reports.
New family of non-precious metal catalysts outperform platinum for oxygen-reduction reaction in fuel cells at 10% the production cost
September 23, 2013
|ORR polarisation curves of Pt/C and FeCo-OMPC catalysts before and after 10,000 potential cycles in O2-saturated 0.1 M HClO4. Potential cycling was carried out from 0.6 to 1.0 V vs. RHE at 50 mV s−1. Cheon et al. Click to enlarge.|
Researchers from Ulsan National Institute of Science and Technology (UNIST), Korea Institute of Energy Research (KIER), and Brookhaven National Laboratory have discovered a new family of non-precious metal catalysts based on ordered mesoporous porphyrinic carbons (M-OMPC) with high surface areas and tunable pore structures. Porphyrins are any of a class of heterocyclic compounds containing four pyrrole rings arranged in a square.
These catalysts exhibit better performance than platinum in the oxygen-reduction reaction (ORR) important for fuel cells at 10% of the production cost of a platinum catalyst, the team said. The finding, described in an open access paper in Nature’s Scientific Reports, is potentially a step towards reducing the cost of fuel cell technology—one of the impediments to widespread commercialization.
ARPA-E awarding $3.5M to Berkeley Lab project to develop novel enzymatic gas-to-liquids pathway
September 22, 2013
On 19 September, the Advanced Research Project Agency-Energy (ARPA-E) awarded $34 million to 15 projects to find advanced biocatalyst technologies that can convert natural gas to liquid fuel for transportation. (Earlier post.) The largest award in the technical area of High-Efficiency Biological Methane Activation in the new program, (Reducing Emissions using Methanotrophic Organisms for Transportation Energy—REMOTE, earlier post), provides $3.5 million to a team led by Dr. Christer Jansson at Lawrence Berkeley National Laboratory (LBNL) to work on a novel methylation process to convert natural gas to liquid transportation fuels.
The project, called “Enzyme Engineering for Direct Methane Conversion,” involves designing a novel enzyme—a PEP methyltransferase (PEPMase)—by engineering an existing enzyme to accept methane instead of carbon dioxide. This methylation process, which does not exist in nature, will be used as the basis for the gas-to-liquids pathway.
New core-shell bi-layer nanocatalyst tolerant to CO; potential for low-temperature fuel cells with reformates
September 21, 2013
Researchers at Brookhaven National Laboratory have created a high-performing bi-layer durable nanocatalyst that is tolerant to carbon monoxide, a catalyst-poisoning impurity in hydrogen derived from natural gas. The novel core-shell structure—ruthenium coated with platinum—resists damage from carbon monoxide as it drives the energetic reactions central to electric vehicle fuel cells and similar technologies.
The single crystalline Ru cores with well-defined Pt bilayer shells address the issues in using a dissolution-prone metal, such as ruthenium, to alleviate carbon monoxide poisoning, and thereby open the door for commercialization of low-temperature fuel cells that can use inexpensive reformates (H2 with CO impurity) as the fuel, the authors noted. Their paper is published in the journal Nature Communications.
MIT team discovers new family of materials with best performance yet for oxygen evolution reaction; implications for fuel cells and Li-air batteries
September 19, 2013
|A diagram of the molecular structure of double perovskite shows how atoms of barium (green) and a lanthanide (purple) are arranged within a crystalline structure of cobalt (pink) and oxygen (red). Grimaud et al. Click to enlarge.|
MIT researchers have found a new family of highly active catalyst materials that provides the best performance yet in the oxygen evolution reaction (OER) in electrochemical water-splitting—a key requirement for energy storage and delivery systems such as advanced fuel cells and lithium-air batteries.
The materials, double perovskites (Ln0.5Ba0.5)CoO3−δ (Ln=Pr, Sm, Gd and Ho), are a variant of a mineral that exists in abundance in the Earth’s crust. Their remarkable ability to promote oxygen evolution in a water-splitting reaction is detailed in a paper appearing in the journal Nature Communications. The work was conducted by Dr. Yang Shao-Horn, the Gail E. Kendall Professor of Mechanical Engineering and Materials Science and Engineering; postdoc Alexis Grimaud; and six others.
New route for upgrading bio-oil to biogasoline via molecular distillation and catalytic cracking
September 18, 2013
|Bio-oil-graded upgrading route based on molecular distillation and catalytic cracking. Credit: ACS, Wang et al. Click to enlarge.|
A team at Zhejiang University, China, has developed a novel cracking technology for the upgrading of bio-oil, produced by the fast pyrolysis of biomass, to biogasoline. In a paper published in the ACS journal Energy & Fuels, they report that the co-cracking of the distilled fraction (DF) from bio-oil molecular distillation and ethanol produced a well-defined gasoline phase, and that both increasing the reaction temperature and adopting pressurized cracking benefited the yield and quality of this gasoline phase.
Under optimum reaction temperature and pressure, co-cracking of the DF and ethanol, with different weight ratios, all generated high-quality gasoline phases. Under 400 °C and 2 MPa, co-cracking of DF and ethanol with a weight ratio of 2:3 produced a high gasoline phase yield of 25.9 wt %; the hydrocarbon content in this gasoline phase was 98.3%. CO2, CO, and C3H8 (propane) were the main gaseous products, and a low coke yield of 3.2 wt % was achieved.
PNNL team finds correlation between reaction mechanism for zeolite SCR catalyst for NOx aftertreatment and bacterial enzyme catalysis
September 11, 2013
|Computer model of Cu-SSZ-13 shows nitric oxide (ball-and-stick) interacting with a positively charged copper ion (copper ball) at an unexpected angle (red dotted lines). Photo courtesy of Kwak et al. Click to enlarge.|
A team of researchers in the Institute for Integrated Catalysis at Pacific Northwest National Laboratory led by chemist János Szanyi has proposed a reaction mechanism for a highly active zeolite catalyst (Cu-SSZ-13) used in selective catalytic reduction (SCR) NOx aftertreatment systems for diesel emissions. A paper on their work is published in the journal Angewandte Chemie International Edition.
Although the catalyst is in use, exactly how it converts NOx to nitrogen and water with the help of ammonia (urea) hasn’t been entirely clear. The new research finds that the catalyst works much the same way that similar bacterial enzymes do: by coming at the target from the side rather than head on. The finding provides insight into how to make better catalytic converters.
NRL researchers optimizing two-step process for synthesis of jet-fuel-range hydrocarbons from CO2
September 09, 2013
Researchers at the US Naval Research Laboratory (NRL) are investigating an optimized two-step process for the synthesis of liquid hydrocarbons in the jet fuel range from CO2 and hydrogen. The process, reported in the ACS journal Energy & Fuels, could leverage a recently reported process, also developed by NRL, to recover CO2 from sea water.
CO2 is 140 times more concentrated in seawater than in air on a weight per volume basis (g/mL), the authors note. With scaling and optimization of this CO2 recovery technology already underway, NRL researchers and others are working on new and improved catalysts for the conversion of CO2to useful hydrocarbons.
Berkeley Lab researchers at JCAP develop unique semiconductor/catalyst construct for production of H2 from sunlight
August 30, 2013
Researchers with the US Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Joint Center for Artificial Photosynthesis (JCAP) have developed a method by which molecular cobalt-containing hydrogen production catalysts can be interfaced with a semiconductor that absorbs visible light.
Coupling the absorption of visible light with the production of hydrogen in one material enables the generation of a fuel simply by illuminating the photocathode, says Gary Moore, a chemist with Berkeley Lab’s Physical Biosciences Division and principal investigator for JCAP. “No external electrochemical forward biasing is required.” Moore is the corresponding author of a paper describing this research in the Journal of the American Chemical Society (JACS).