The ultrafast, ultrabright X-ray pulses of the Linac Coherent Light Source (LCLS) have enabled unprecedented views of a catalyst in action, an important step in the effort to develop cleaner and more efficient energy sources. Scientists at the SLAC National Accelerator Laboratory used LCLS, together with computerized simulations, to reveal surprising details of a short-lived early state in a chemical reaction occurring at the surface of a catalyst sample.
Bringing the concept of an “artificial leaf” closer to reality, a team of researchers at Massachusetts Institute of Technology has published a detailed analysis of all the factors that could limit the efficiency of such a system. The new analysis lays out a roadmap for a research program to improve the efficiency of these systems, and could quickly lead to the production of a practical, inexpensive and commercially viable prototype.
A new analytical theory has been developed at Purdue University that shows how to design experiments to study ways of controlling dendrite growth on electrodes in lithium-ion batteries. Using this approach, the researchers have shown theoretically how to control or eliminate the formation of these dendrites, which cause lithium-ion batteries to fail. The advance could help improve safety and might enable the batteries to be charged within a matter of minutes instead of hours.
The Fischer-Tropsch process is used for producing fuels from synthesis gas, which in turn is made from natural gas, biomass, or coal. Large reserves of shale or natural gas now changing the world energy market have raised interest in this technology, but prior reactors have been too bulky. Inspired by patents from the 1960s audio cassette recording industry, University of Amsterdam chemists have recently developed a new Fischer-Tropsch catalyst that is significantly cheaper and more scalable.
Tiny particles of titanium dioxide are found as key ingredients in common products such as paint and toothpaste. When reduced to the nanoscale, these particle acquire catalytic ability. A team of chemists has recently developed a synthesis to produce these nanoparticles at room temperature in a polymer network. Their analysis has revealed the crystalline structure of the nanoparticles and is a major step forward in the development of polymeric nanoreactors.
To make fuel cells more economical, engineers want a fast and efficient iron-based molecule that splits hydrogen gas to make electricity. Researchers at Pacific Northwest National Laboratory have recently reported the development of such a catalyst. Made from a synthetic molecule, it is the first iron-based catalyst that converts hydrogen directly to electricity, and it might help make those fuel cells less expensive.
Chemists at Boston College have designed a new class of catalysts triggered by the charge of a single proton, the team reports in Nature. The simple organic molecules offer a sustainable and highly efficient platform for chemical reactions that produce sets of molecules crucial to advances in medicine and the life sciences.
A new review published by Wiley focuses on the recent progress in the theoretical and experimental efforts to obtain a deeper understanding of the effects of carbon nanostructure and surface functional groups on proton affinity, metal/CNF interactions, and electronic properties, as well as their catalytic consequences.
With a width of just a few nanometers, tiny tunnels recently created by researchers in Germany and the United States in graphite have been formed using heated nickel nanoparticles. Capillary action, aided by a hydrogen-to-methane gas conversion, has given scientists the basis for self-organized structuring of the interior. Nanoporous graphite could have many applications in medicine and battery technology.
In a case of the Goldilocks story retold at the molecular level, scientists at Argonne National Laboratory and Northwestern University have discovered a new path to the development of more stable and efficient catalysts. The research team sought to create "nanobowls"—nanosized bowl shapes that allow inorganic catalysts to operate selectively on particular molecules.
Modern advances in well controlled fabrication of metal nanoparticles and their composites have assisted material scientists in the design and efficient utilization of desired catalysts, as is evidenced by explosive growth in the nanocatalysis field. A new review published in Advanced Energy Materials highlights the progress of nanocatalysis through rational design.
Sulfur compounds in petroleum fuels have met their nanostructured match. University of Illinois researchers developed mats of metal oxide nanofibers that scrub sulfur from petroleum-based fuels much more effectively than traditional materials.
A research group at NIST has developed a relatively simple, fast, and effective method of depositing uniform, ultrathin layers of platinum atoms on a surface. The new process exploits an unexpected feature of electrodeposition of platinum—if you drive the reaction much more strongly than usual, a new reaction steps in to shuts down the metal deposition process, allowing an unprecedented level of control of the film thickness.
A chemical nanostructure developed by Boston College researchers behaves much like the pores of the skin, serving as a precise control for a typically stubborn method of catalysis that is the workhorse of industrial chemistry.
Colloidal suspensions of metal nanoparticles in water passes too easily through commonly used macroporous polymeric membranes. To handle these nanofluids, researchers have built a membrane equipped functionalized proteins that can act as filters for nanoscaled particles in aqueous solutions. Such a nano-sieve could act as a catalyzer or could capture solar energy.
Scientists in Japan have developed a high activity gold nanoparticle catalyst that simplifies the function of enzymes in capturing substances. This new type of catalyst mimics enzyme function on the surface of cell membranes, which capture molecules of designated lengths and shapes. The findings indicate that gold nanoparticles thus equipped could support biological activities as a catalyst in the reactions of the living body.
Photoelectrochemical (PEC) tandem solar cells offer a way to produce hydrogen directly from water. But efforts to produce an efficient cell have only resulted in extremely expensive prototypes. Researchers in Switzerland have recently developed a PEC, however, that is made from inexpensive materials and achieves up to 16% efficiency.
Catalysis is an incredibly valuable tool in the field of chemistry, but it typically requires precious metals that are both expensive and potentially harmful to the environment. Researchers in Sweden say they have discovered that copper, which is not typically known for its catalytic properties, had unexpectedly been responsible for catalytic activity as part of research into iron catalysts.
Oxide catalysts play an integral role in many chemical transformations. Greener, more efficient chemical processes would benefit greatly from solid oxide catalysts that are choosier about their reactants, but achieving this has prove a challenge. Now, a team of researchers have developed a straightforward and generalizable process for making reactant-selective oxide catalysts by encapsulating the particles in a sieve-like film that blocks unwanted reactants.
Through spectroscopic investigations on a hydrogen-producing enzyme, researchers in Germany have found that environment of the catalytic site acts as an electron reservoir in the enzyme. This finding means that the enzyme can produce hydrogen at a highly efficient rate and could be useful as a renewable energy source.
Hydrogen production by solar water splitting in photoelectrochemical cells (PEC) has long been considered the holy grail of sustainable energy research. Iron oxide is a promising electrode material, and now an international team of researchers gained in-depth insights into the electronic structure of an iron oxide electrode, while it was in operation. This opens up new possibilities for an affordable hydrogen production from solar energy.
Solar, wind and other renewable energy sources reduce consumption of fossil fuels but also pose challenges to the electrical grid because their power generation fluctuates. A team of researchers at Stanford and SLAC National Accelerator Laboratory has developed a mix of materials that shows promise as a cost-effective alternative to standard batteries—able to quickly and efficiently charge and discharge their energy over thousands of charges, with no energy loss after 1,000 charges.
Platinum works well as a catalyst in hydrogen fuel cells, but it has at least two drawbacks: It is expensive, and it degrades over time. Brown University chemists have engineered a cheaper and more durable catalyst using graphene, cobalt, and cobalt-oxide—the best nonplatinum catalyst yet.
Lawrence Berkeley National Laboratory researchers have combined the best properties of heterogeneous and homogeneous catalysts by encapsulating metallic nanoclusters within the branched molecular arms of dendrimers. The results are heterogenized homogeneous nanocatalysts that are sustainable and feature high reactivity and selectivity.
The tiny metal particles in catalytic converters that work to clean up vehicle emissions require a minimum temperature to function efficiently, and work poorly when cold. A new measuring method using photoemission electron microscopy has made it possible to examine many different types of these particles at the same time, shedding light on what exactly affects converter efficiency.