Iron catalysts remove oxygen inexpensively, but are susceptible to rust or oxidation in biofuel production. Precious metals that resist corrosion are even less efficient at removing oxygen. But adding just a touch of palladium to the iron produces a catalyst that quickly removes oxygen atoms, easily releases the desired products, and doesn't rust, according to scientists at Pacific Northwest National Laboratory and Washington State Univ.
Swedish and Chinese researchers have recently shown how a unique nano-alloy composed of palladium nano-islands embedded in tungsten nanoparticles creates a new type of catalysts for highly efficient oxygen reduction, the most important reaction in hydrogen fuel cells. Their results are published in the scientific journal Nature Communications.
The key to creating a material that would be ideal for converting solar energy to heat is tuning the material’s spectrum of absorption just right: It should absorb virtually all wavelengths of light that reach Earth’s surface from the sun—but not much of the rest of the spectrum, since that would increase the energy that is reradiated by the material, and thus lost to the conversion process.
Researchers are developing a robotic fabric that moves and contracts and is embedded with sensors, an approach that could lead to "active clothing" or a new class of "soft" robots. The robotic fabric, developed at Purdue Univ., is a cotton material containing sensors made of a flexible polymer and threadlike strands of a shape-memory alloy that return to a coiled shape when heated, causing the fabric to move.
Donald Sadoway and his colleagues at the Massachusetts Institute of Technology have already started a company to produce electrical-grid-scale liquid batteries, whose layers of molten material automatically separate due to their differing densities. But a newly developed formula substitutes different metals for the molten layers. The new formula allows the battery to work at a much lower temperature.
Researchers from North Carolina State Univ. have developed a technique for controlling the surface tension of liquid metals by applying very low voltages, opening the door to a new generation of reconfigurable electronic circuits, antennas and other technologies. The technique hinges on the fact that the oxide “skin” of the metal acts as a surfactant, lowering the surface tension between the metal and the surrounding fluid.
Researchers have been trying to increase the efficiency of solid oxide fuel cells by lowering the temperatures at which they run. In a serendipitous finding at Pacific Northwest National Laboratory, researchers have created a new form of strontium-chromium oxide that performs as a semiconductor and also allows oxygen to diffuse easily, a requirement for a solid oxide fuel cell.
When it comes to diesel engine catalysts, which are responsible for cleansing exhaust fumes, platinum has unfortunately proved to be the only viable option. This has resulted in material costs alone accounting for half of the price of a diesel catalyst. Researchers in Denmark say they have developed a new way to manufacture catalysts that may result in a 25% reduction in the use of platinum.
A new concept in metallic alloy design has yielded a multiple-element material that not only tests out as one of the toughest on record, but, unlike most materials, the toughness as well as the strength and ductility of this alloy actually improves at cryogenic temperatures. This multi-element alloy was synthesized and tested through a collaboration of researchers.
A new concept in metallic alloy design called “high-entropy alloys” has yielded a multiple-element material that tests out as one of the toughest on record. But, unlike most materials, the toughness as well as the strength and ductility of this alloy, which contains five major elements, actually improves at cryogenic temperatures.
When metallic lithium forms and deposits during the charging process in a lithium-ion battery, it can lead to a reduced battery lifespan and even short circuits. Using neutron beams, scientists have now peered into the inner workings of a functioning battery without destroying it. In the process, they have resolved this so-called lithium plating mystery.
The field of astrophysics has a stubborn problem and it’s called lithium. The quantities of lithium predicted to have resulted from the Big Bang are not actually present in stars. But the calculations are correct, a fact which has now been confirmed for the first time in experiments conducted at the underground laboratory in the Gran Sasso mountain in Italy.
Sensors made with copper could be cheap, light, flexible and highly conductive. Making such concepts affordable enough for general use remains a challenge but a new way of working with copper nanowires and a PVA “nano glue” could be a game-changer. Engineers in Australia have found a way of making flexible copper conductors cost-effective enough for commercial applications.
For tiny fractions of a second, when illuminated by a laser pulse, quartz glass can take on metallic properties. The phenomenon, recently revealed by large-scale computer simulations, frees electrons, allowing quartz to become opaque and conduct electricity. The effect could be used to build logical switches which are much faster than today’s microelectronics.
In a recent paper, a team at Stanford Univ. which includes materials science expert Yi Cui and 2011 R&D Magazine Scientist of the Year Steven Chu report that they have taken a big step toward accomplishing what battery designers have been trying to do for decades: design a pure lithium anode.
By colliding ultra-small gold particles with a surface and analyzing the resulting fragments, a trio of scientists at Pacific Northwest National Laboratory discovered how and why the particles break. This information is important for controlling the synthesis of these tiny building blocks that are of interest to catalysis, energy conversion and storage, and chemical sensing.
The yield so far is small, but chemists at the Univ. of Oregon have developed a low-energy, solution-based mineral substitution process to make a precursor to transparent thin films. The inorganic process is a new approach to transmetalation, in which individual atoms of one metal complex are individually substituted in water. The innovation could find use in electronics and alternative energy devices.
A new type of catalyst, based on carbon, can facilitate two opposite reactions: electrolysis of water and combustion of hydrogen with oxygen. This bi-functionality, developed by researchers in Germany, is made possible from its construction: manganese-oxide or cobalt-oxide nanoparticles which are embedded in specially modified carbon, then integrated with nitrogen atoms in specific positions.
With a chemical “trick”, scientists in Germany have succeeded in isolating a stable gold carbene complex. Experts have been proposing gold carbenes as essential short-lived intermediates in catalytic reactions, but they elude study because of their high reactivity. Chemist Prof. Dr. Bernd F. Straub and his team are the first to have created the basis for directly examining the otherwise unstable gold-carbon double bond.
Iron is present in tiny concentrations in seawater, on the order of a few billionths of a gram in a liter. However, its availability in seawater can have a profound effect on phytoplankton growth and, consequently, the Earth's carbon cycle. In recent research, an assessment was made of the various sources of dissolved iron in the north Atlantic Ocean and surprising discoveries were made about their origins.
Ancient Japanese gold leaf artists were truly masters of their craft. An analysis of six of these Japanese paper screens show that these artifacts are gilded with gold leaf that was hand-beaten to the nanometer scale. The study was able to prove this without any damage to the screens through the use of x-ray fluorescence spectroscopy.
Titanium dioxide nanoparticles show great promise as optical encapsulants or fillers for tunable refractive index coatings. However, they've been largely shunned because they’ve been difficult and expensive to make. Scientists at Sandia National Laboratories have now come up with an inexpensive way to synthesize properly sized titanium dioxide nanoparticles and is seeking partners who can demonstrate the process at industrial scale.
A breakthrough has been made in identifying the origin of superconductivity in high-temperature superconductors, which has puzzled researchers for the past three decades. Researchers in the U.K. have found that ripples of electrons, known as charge density waves or charge order, create twisted ‘pockets’ of electrons in these materials, from which superconductivity emerges.
A new nanoparticle platform developed in California increases the efficiency of drug delivery and allows excess particles to be washed away. A simple etching technique using biocompatible chemicals rapidly disassembles and removes the silver nanoparticles outside living cells. This method leaves only the intact nanoparticles for imaging or quantification, revealing which cells have been targeted and how much each cell internalized.
Surface catalysts are notoriously difficult to study mechanistically, but scientists at two universities have recently shown how to get real-time reaction information from silver nanocatalysts that have long frustrated attempts to describe their kinetic behavior in detail. The key to the team's success was bridging a size gap that had represented a wide chasm to researchers in the past.