Worldwide scientific collaboration develops catalysis breakthrough

A new article  just published in Nature Catalysis shows the simple ways of controlling the structure of platinum nanoparticles and tuning their catalytic properties. 

Research led by Cardiff Catalysis Institute (CCI) in collaboration with scientists from Lehigh University, Jazan University, Zhejiang University, Glasgow University, University of Bologna, Research Complex at Harwell (RCaH), and University College London have combined their unique skills to develop and understand using advanced characterisation methods (particularly TEM and B18 at Diamond Light Source), how it is possible to use a simple preparation method to control and manipulate the structures of metal nanoparticles. These metal nanoparticles are widely used by industry as innovative catalysts for the production of bulk chemicals like polymers, liquid fuels (e.g., diesel, petrol) and other speciality chemicals (pharmaceutical products).

>Read more on the Diamond Light Source website

Image: Andy Beale works at Diamond Light Source.

Analysis of fingermarks with synchrotron techniques provide new insights

A new study by researchers from Curtin University using the infrared (IR) and X-ray fluorescence microscopy (XFM) beamlines at the Australian Synchrotron has provided a better understanding of the chemical and elemental composition of latent fingermarks.

The findings by lead researchers Prof Simon Lewis and Dr Mark Hackett may provide opportunities to optimise current fingermark detection methods or identify new detection strategies for forensic purposes.
Latent fingermarks are generally described as those requiring some process to make them readily visible to the eye. These fingermarks are typically made up of natural skin secretions, along with contaminants (such as food or cosmetics) picked up from various surfaces.
The detection of latent fingermarks is often crucial in forensic investigations, but this is not always a straightforward task. “We know that there are issues in detecting fingermarks as they get older, and also under certain environmental conditions”, said Lewis, whose main research focus is forensic exchange evidence.

“In order to improve our ability to detect fingermarks, we need to understand the nature of fingermark residue, and this includes both the organic and inorganic components. Many chemical components in fingermark residue are present at very low levels, and we don’t know how they are distributed within the fingermark. This is what took us to the Australian Synchrotron.”

>Read more on the Australian Synchrotron at ANSTO website

Study reveals ‘radical’ wrinkle in forming complex carbon molecules in space

Unique experiments at Berkeley Lab’s Advanced Light Source shine a light on a new pathway for carbon chemistry to evolve in space.

A team of scientists has discovered a new possible pathway toward forming carbon structures in space using a specialized chemical exploration technique at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The team’s research has now identified several avenues by which ringed molecules known as polycyclic aromatic hydrocarbons, or PAHs, can form in space. The latest study is a part of an ongoing effort to retrace the chemical steps leading to the formation of complex carbon-containing molecules in deep space. PAHs – which also occur on Earth in emissions and soot from the combustion of fossil fuels – could provide clues to the formation of life’s chemistry in space as precursors to interstellar nanoparticles. They are estimated to account for about 20 percent of all carbon in our galaxy, and they have the chemical building blocks needed to form 2D and 3D carbon structures.

>Read more on the ALS at Berkeley Lab website

Image: This composite image shows an illustration of a carbon-rich red giant star (middle) warming an exoplanet (bottom left) and an overlay of a newly found chemical pathway that could enable complex carbons to form near these stars.
Credits: ESO/L. Calçada; Berkeley Lab, Florida International University, and University of Hawaii at Manoa.

Brookhaven Lab and University of Delaware begin joint initiative

Through this partnership, scientists from both institutions will conduct collaborative research on rice soil chemistry and quantum materials.

The U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and the University of Delaware (UD) have begun a two-year joint initiative to promote collaborative research in new areas of complementary strength and strategic importance. Though Brookhaven Lab and UD already have a tradition of collaboration, especially in catalysis, this initiative encourages partnerships in strategic areas where that tradition does not yet exist. After considering several potential areas, a committee from Brookhaven and UD selected two projects—one on rice soil chemistry and the other on quantum materials—for the new initiative. For each project, one graduate student based at Brookhaven and one graduate student from UD will work with and be supervised by a principal investigator from each respective institution. The research, to start in October 2019, is funded separately by the two institutions. Brookhaven funding is provided through its Laboratory-Directed Research and Development program, which promotes highly innovative and exploratory research that supports the Lab’s mission and areas for growth.

>Read more on the NSLS-II at Brookhaven Lab website

Image: Principal investigators from Brookhaven Lab and the University of Delaware (UD) will collaborate on two different research projects through a new joint initiative. Brookhaven’s Peter Johnson (left) and UD’s Stephanie Law (second from left) will measure the energy level spectrum of a topological insulator, a new type of material that behaves as an insulator internally but as a conductor on the surface; Brookhaven’s Ryan Tappero (second from the right) and UD’s Angelia Seyfferth (right) will study how toxic and nutrient metals are distributed in rice grain.

Unravelling the growth mechanism of the coprecipitation of iron oxide nanoparticles

Applications involving iron oxide nanoparticles (IONPs) and nanomaterials in general, are expected to provide solutions to many problems in the fields of healthcare, energy and environment. Magnetic nanoparticles (such as IONPs) have been in the exploratory stage for cancer diagnostic (e.g.in the form of magnetic resonance imaging contrast agents) for more than three decades and treatment (e.g.via hypothermia) in the recent decade. However, success stories are rare, partly due to the limited performance of commercially available nanoparticles, related to the particle quality attributes such as size and shape, polydispersity, crystallinity and surface chemistry. Although today’s literature provides many reports on the synthesis of highly complex nanoparticles with superior properties respect the currently approved products, there seems to be a gap to the application of these materials to fully exploit their enhanced capabilities. This is due, at least partly, to obstacles such as low yield and, most importantly, the robustness and reproducibility of the synthesis method. Hence, detailed studies on nanoparticle formation mechanisms are essential to guarantee that successful syntheses are not a “one-off” but can be performed and reproduced at various research institutions at small to large scales. This work presents such a detailed study, unravelling the growth mechanism of the co-precipitation of IONPs in solution with the aid of synchrotron X-Ray diffraction.

>Read more on the Elettra website

Image: TEM images of the nanoparticles formed after 30 s, 1, 2, 3, 4, 5, 7 and 10 min of reaction.

Surface instability and chemical reactivity of ZrSiS and ZrSiSe nodal-line semimetals

Among topological semimetals, in nodal-line semimetals (NLSM) conduction and valence bands cross each other. In particular, in NLSM, topological constraints protect band crossings and, moreover, band touching forms nodal lines or rings. Recently, topological nodal lines have been observed in bulk ZrSiX compounds (X = S, Se, Te). In ZrSiX, a tetragonal structure is formed by the stacking of X-ZrSi-Zr-X slabs covalently bonded between each other, whose strength decreases by replacing S with Se or Te ions. This class of materials exhibits large and non-saturating magnetoresistance and ultrahigh mobility of charge carriers.
The control over surface phenomena, including oxidation, degradation, and surface reconstruction is a crucial step in order to evaluate the feasibility of the exploitation in technology of ZrSiX.
By means of X-ray photoelectron spectroscopy (XPS) carried out at the APE-HE beamline, high-resolution electron energy loss (HREELS) and density functional theory, an international team of researchers from Italy, China, Russia, Taiwan, and USA (coordinated by University of L’Aquila) has studied the evolution of ZrSiS and ZrSiSe surfaces in oxygen and ambient atmosphere.
The chemical activity of ZrSiX compounds is mainly determined by the interactions of Si layer with ZrX sublayer. Any adsorption provides distortion of the Si layer (flat in bulk). In the case of ZrSiS, the ZrS sublayer is almost the same as in bulk and therefore adsorption is unfavorable because it provides distortions of Si layer. In the case of ZrSiSe, the ZrSe sublayer is already strongly distorted (structure different from bulk), and, therefore, further distortion of Si layer by adsorption is favorable (see figure).

>Read more on the Elettra website

Image: Atomic structure of different steps of the process of the oxidation of ZrSiSe from (a-d) Zr-sites and (e-h) Si-sites. Red, light blue, black and yellow balls represent O, Zr, Se, and Si atoms, respectively. On panels (a) and (e) physical adsorption of single oxygen molecule is depicted. Panels (b) and (f) represent the situation of uniform coverage of the surfaces by molecular oxygen. In panels (c) and (g), decomposition of single oxygen molecule on the surfaces is represented. Panels (d) and (h) show total oxidation of the surfaces.

Keeping nuclear power safe

Nuclear energy is clean, powerful, affordable, and zero-emission. A new study uses the Canadian Light Source (CLS) at the University of Saskatchewan to help ensure that waste from nuclear power plants remains safe and secure for thousands of years to come.
The project, led by Dan Kaplan and Dien Li, researchers at the Savannah River National Laboratory in South Carolina, looks at storing iodine, which is generated during uranium use, including in nuclear power generation.
Among the challenges of iodine management is its slow rate of decay—it has a half-life of 16 million years. Iodine is volatile and highly mobile in the environment, making containment critically important in nuclear waste management.
Currently, nuclear waste disposal sites use Ag-zeolite to sequester iodine from nuclear waste streams, which is then encased in concrete to prevent leaching.

>Read more on the Canadian Light Source website

Image: Samples of different formulations of cement that were tested for their ability to immobilize radioiodine.

Watching molecules in a light-triggered catalyst ring ‘like an ensemble of bells’

A better understanding of these systems will aid in developing next-generation energy technologies.

Photocatalysts ­– materials that trigger chemical reactions when hit by light – are important in a number of natural and industrial processes, from producing hydrogen for fuel to enabling photosynthesis.
Now an international team has used an X-ray laser at the Department of Energy’s SLAC National Accelerator Laboratory to get an incredibly detailed look at what happens to the structure of a model photocatalyst when it absorbs light.
The researchers used extremely fast laser pulses to watch the structure change and see the molecules vibrating, ringing “like an ensemble of bells,” says lead author Kristoffer Haldrup, a senior scientist at Technical University of Denmark (DTU). This study paves the way for deeper investigation into these processes, which could help in the design of better catalysts for splitting water into hydrogen and oxygen for next-generation energy technologies.
“If we can understand such processes, then we can apply that understanding to developing molecular systems that do tricks like that with very high efficiency,” Haldrup says.

>Read more on the Linac Coherent Light Source at SLAC website

Image: When photocatalyst molecules absorb light, they start vibrating in a coordinated way, like an ensemble of bells. Capturing this response is a critical step towards understanding how to design molecules for the efficient transformation of light energy to high-value chemicals.
Credit: Gregory Stewart/SLAC National Accelerator Laboratory

A series of stories celebrating the periodic table’s 150th anniversary

The ESRF is celebrating the International Year of the Periodic Table, because its elements are omnipresent in the research done at the facility. We will publish a series of stories on different elements during the coming weeks. The first series is about the fascinating elements at the bottom of the periodic table.

See the series start here on the ESRF website

Image: Kristina Kvashnina in front of the periodic table. She is from the Helmoltz-Zentrum Dresden-Rossendorf (HZDR) but based at the Rossendorf Beamline (BM20) of ESRF in Grenoble.
Credits: Moulyneux

Single atoms can make more efficient catalysts

Detailed observations of iridium atoms at work could help make catalysts that drive chemical reactions smaller, cheaper and more efficient.

Catalysts are chemical matchmakers: They bring other chemicals close together, increasing the chance that they’ll react with each other and produce something people want, like fuel or fertilizer.

Since some of the best catalyst materials are also quite expensive, like the platinum in a car’s catalytic converter, scientists have been looking for ways to shrink the amount they have to use.

Now scientists have their first direct, detailed look at how a single atom catalyzes a chemical reaction. The reaction is the same one that strips poisonous carbon monoxide out of car exhaust, and individual atoms of iridium did the job up to 25 times more efficiently than the iridium nanoparticles containing 50 to 100 atoms that are used today.

>Read more on the SSRL at SLAC website

Image: Scientists used a combination of four techniques, represented here by four incoming beams, to reveal in unprecedented detail how a single atom of iridium catalyzes a chemical reaction.
Credit: Greg Stewart/SLAC National Accelerator Laboratory

Improving lithium-ion battery capacity

Toward cost-effective solutions for next-generation consumer electronics, electric vehicles and power grids.

The search for a better lithium-ion battery—one that could keep a cell phone working for days, increase the range of electric cars and maximize energy storage on a grid—is an ongoing quest, but a recent study done by Canadian Light Source (CLS) scientists with the National Research Council of Canada (NRC) showed that the answer can be found in chemistry.
“People have tried everything at an engineering level to improve batteries,” said Dr. Yaser Abu-Lebdeh, a senior research officer at the NRC, “but to improve their capacity, you have to play with the chemistry of the materials.”

>Read more on the Canadian Light Source website

Image: The decomposition of a polyvinylidene fluoride (PVDF) binder in a high energy battery.
Credit: Jigang Zhou

Scientists produce 3-D chemical maps of single bacteria

Researchers at NSLS-II used ultrabright x-rays to generate 3-D nanoscale maps of a single bacteria’s chemical composition with unparalleled spatial resolution.

Scientists at the National Synchrotron Light Source II (NSLS-II)—a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Brookhaven National Laboratory—have used ultrabright x-rays to image single bacteria with higher spatial resolution than ever before. Their work, published in Scientific Reports, demonstrates an x-ray imaging technique, called x-ray fluorescence microscopy (XRF), as an effective approach to produce 3-D images of small biological samples.

“For the very first time, we used nanoscale XRF to image bacteria down to the resolution of a cell membrane,” said Lisa Miller, a scientist at NSLS-II and a co-author of the paper. “Imaging cells at the level of the membrane is critical for understanding the cell’s role in various diseases and developing advanced medical treatments.”
The record-breaking resolution of the x-ray images was made possible by the advanced capabilities of the Hard X-ray Nanoprobe (HXN) beamline, an experimental station at NSLS-II with novel nanofocusing optics and exceptional stability.
“HXN is the first XRF beamline to generate a 3-D image with this kind of resolution,” Miller said.

>Read more on the NSLS-II at Brookhaven National Laboratory website

Image: NSLS-II scientist Tiffany Victor is shown at the Hard X-ray Nanoprobe, where her team produced 3-D chemical maps of single bacteria with nanoscale resolution.

New clues to cut through the mystery of Titan’s atmospheric haze

A team including Berkeley Lab scientists homes in on a ‘missing link’ in Titan’s one-of-a-kind chemistry.

Saturn’s largest moon, Titan, is unique among all moons in our solar system for its dense and nitrogen-rich atmosphere that also contains hydrocarbons and other compounds, and the story behind the formation of this rich chemical mix has been the source of some scientific debate.
Now, a research collaboration involving scientists in the Chemical Sciences Division at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has zeroed in on a low-temperature chemical mechanism that may have driven the formation of multiple-ringed molecules – the precursors to more complex chemistry now found in the moon’s brown-orange haze layer.
The study, co-led by Ralf Kaiser at the University of Hawaii at Manoa and published in the Oct. 8 edition of the journal Nature Astronomy, runs counter to theories that high-temperature reaction mechanisms are required to produce the chemical makeup that satellite missions have observed in Titan’s atmosphere.

>Read more on the Advanced Light Source/Berkeley Lab website

Image: The atmospheric haze of Titan, Saturn’s largest moon (pictured here along Saturn’s midsection), is captured in this natural-color image (box at left). A study that involved experiments at Berkeley Lab’s Advanced Light Source has provided new clues about the chemical steps that may have produced this haze.
Credits: NASA Jet Propulsion Laboratory, Space Science Institute, Caltech

Single atoms break carbon’s strongest bond

Scientists discovered that single atoms of platinum can break the bond between carbon and fluorine, one of the strongest known chemical bonds.

An international team of scientists including researchers at Yale University and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have developed a new catalyst for breaking carbon-fluorine bonds, one of the strongest chemical bonds known. The discovery, published on Sept. 10 in ACS Catalysis, is a breakthrough for efforts in environmental remediation and chemical synthesis.

“We aimed to develop a technology that could degrade polyfluoroalkyl substances (PFAS), one of the most challenging pollutant remediation problems of the present day,” said Jaehong Kim, a professor in the department of chemical and environmental engineering at Yale University. “PFAS are widely detected all over the world, from Arctic biota to the human body, and concentrations in contaminated groundwater significantly exceed the regulatory limit in many areas. Currently, there are no energy-efficient methods to destroy these contaminants. Our collaboration with Brookhaven Lab aims to solve this problem by taking advantage of the unique properties of single atom catalysts.”

>Read more on the NSLS-II at Brookhaven National Laboratory website

Image: Brookhaven scientist Eli Stavitski is shown at NSLS-II’s Inner Shell Spectroscopy beamline, where researchers imaged the physical and chemical complexity of a single-atom catalyst that breaks carbon-fluorine bonds.

Using uranium to create order from disorder

The first demonstration of reversible symmetry lowering phase transformation with heating.

ANSTO’s unique landmark infrastructure has been used to study uranium, the keystone to the nuclear fuel cycle. The advanced instruments at the Australian Synchrotron and the Australian Centre for Neutron Scattering  have not only provided high resolution and precision, but also allowed in situ experiments to be carried out under extreme sample environments such as high temperature, high pressure and controlled gas atmosphere.

As part of his joint PhD studies at the University of Sydney and ANSTO, Gabriel Murphy has been investigating the condensed matter chemistry of a crystalline material, oxygen-deficient strontium uranium oxide, SrUO4-x, which exhibits the unusual property of having ordered defects at high temperatures.

“Strontium uranium oxide is potentially relevant to spent nuclear fuel partitioning and reprocessing,” said Dr Zhaoming Zhang, Gabriel’s ANSTO supervisor and a co-author on the paper with Prof Brendan Kennedy of the University of Sydney that was published recently in Inorganic Chemistry.
Uranium oxides can access several valence states, from tetravalent— encountered commonly in UO2 nuclear fuels, to pentavalent and hexavalent—encountered in both fuel precursor preparation and fuel reprocessing conditions.
Pertinent to the latter scenario, the common fission daughter Sr-90 may react with oxidised uranium to form ternary phases such as SrUO4.

>Read more on the Australian Synchrotron website

Image: Dr Zhaoming Zhang and Gabriel Murphy.

Graphene-Based Catalyst Improves Peroxide Production

Hydrogen peroxide is an important commodity chemical with a growing demand in many areas, including the electronics industry, wastewater treatment, and paper recycling.

Hydrogen peroxide (H2O2) is a common household chemical, well known for its effectiveness at whitening and disinfecting. It’s also a valuable commodity chemical used to etch circuit boards, treat wastewater, and bleach paper and pulp—a market expected to grow as demand for recycled paper products increases.

Compared to chlorine-based bleaches, hydrogen peroxide is more environmentally benign: the only degradation product of its use is water. However, it’s currently produced through a multistep chemical reaction that consumes significant amounts of energy, generates substantial waste, and requires a catalyst of palladium—a rare and expensive metal. Furthermore, the transport and storage of bulk hydrogen peroxide can be hazardous, making local, on-demand production highly desirable.

Better living through electrochemistry

Scientists seek a way to generate hydrogen peroxide electrochemically—by a much simpler process called the oxygen reduction reaction (ORR). This reaction takes oxygen from the air and combines it with water and two electrons to produce H2O2. If this reaction could be efficiently catalyzed, it could enable the disinfection of water at remote locations, or during disaster recovery, using hydrogen peroxide made from local air and water. For this work, the researchers focused on hydrogen peroxide synthesis in alkaline environments, where the reaction bath can be used directly, such as for bleaching or the treatment of acidic waste streams.

>Read more on the Advanced Light Source website

Image: The production of hydrogen peroxide (H2O2) from oxygen (O2) was efficiently catalyzed by graphene oxide, a form of graphene characterized by various oxygen defects that act as centers for catalytic activity. Depicted are two types of defects: one in which an oxygen atom bridges two carbon atoms above the graphene plane, and one where oxygen atoms replace carbon atoms within the graphene plane.