my.chemie.de
With an accout for my.chemie.de you can always see everything at a glance – and you can configure your own website and individual newsletter.
© Christian Nielinger
A view of the sputtering machine used to produce the material library counters.
Zoom in
Efficient electrocatalysts, which are needed for the production of green hydrogen, for example, are hidden in materials composed of five or more elements. A team from Ruhr-Universität Bochum (RUB) and the University of Copenhagen has developed an efficient method for identifying promising candidates in the myriad of possible materials. To this end, the researchers combined experiments and simulation.
High entropy alloys (HEAs) are chemically complex materials made up of mixtures of five or more elements. What’s interesting about them is that they offer completely new possibilities for the development of electrocatalysts. Such catalysts are urgently needed to make energy conversion processes more efficient, for example for the production and use of green hydrogen. “The problem with HEAs is that, in principle, millions of high-entropy systems are possible and each system involves tens of thousands of different compositions,” explains Professor Alfred Ludwig, who heads the Materials Discovery and Interfaces Chair at RUB. It is almost impossible to tackle such complexity using conventional methods and traditional high-throughput procedures.
The researchers describe a new method in their paper that should help to find promising high entropy alloys for electrocatalysis. In the first step, the team developed a way to produce as many potential compositions as possible. For this purpose, they used a sputtering system that simultaneously applies the five base materials to a carrier. “You can imagine this as five spray cans directed at one point on the target,” explains RUB researcher Dr. Lars Banko. This produces a very specific composition of the five source materials on each point of the carrier, so-called materials libraries. Since this composition is also affected by the position of the sources of the source materials, the research team modified them in the experiment. The materials libraries from the manufacturing processes with six different constellations of the sources were subsequently characterized using high-throughput measurements.
The RUB electrochemistry team then examined the materials libraries in this manner for their electrocatalytic activity.” This enables us to identify trends where possible promising candidates are located,” explains Dr. Olga Krysiak, who with Lars Banko is a lead author of the paper. The team matched this data from the experiment with a large simulation data set provided by the researchers at the University of Copenhagen in order to understand the composition of the materials in greater detail. The comparison between simulation and experiment enables the researchers to explore the atomic scale of electrocatalysts, to estimate the statistical arrangement of atoms on the material surface and to determine their influence on the catalytic activity.
Thriller in the bacterial kingdom
Bacteria have a variety of survival strategies to ensure a sufficient food supply in their densely populated habitats. Certain species of bacteria kill microorganisms of another species, decompose their cells and absorb them as nutrients. The exact mechanism of this process is largely unkno ... more
3D printed surfaces inspired by nature
Scientists can use laser radiation to print tiny structures with high precision. This approach enables them to mimic the superpowers of animals and plants and makes them accessible for engineering applications. To survive in extreme habitats, many animals and plants have developed brilliant ... more
How hepatitis E tricks the immune system
Over three million people are infected with the hepatitis E virus every year. So far, no effective treatment is available. An international team has investigated which factors are important for the virus in the course of its replication cycle and how it manages to maintain the infection. Th ... more
Customized ligands pave the way for new reaction pathways
For the first time, an efficient catalyst for palladium-catalyzed C–C bonding between aryl chlorides and alkyl lithium compounds has been found. This reaction enables simpler synthesis routes for important products, such as pharmaceuticals, while avoiding much salt waste. more
Light plus current: The formula for researching what happens to individual nanoparticles
A combination of dark-field microscopy and electrochemistry can make individual nanoparticles in a liquid medium visible. The technique is suited to determine the activity of catalysts during their use. more
Vibrational spectroscopy - Label-free imaging
Spectroscopic methods are now granting us deep insights into biological systems at previously unattainable spatial and temporal resolutions. Complementing the already well-established fluorescence spectroscopy, the major potential of label-free vibrational spectroscopy has become clear in r ... more
Henning Steinert, born in 1993, studied chemistry at Carl-von-Ossietzky University in Oldenburg, where he researched, among other things, the activation of Si–H bonds on titanium complexes. He is currently working on his doctorate at the Ruhr-Universität Bochum, Chair of Inorganic Chemistry ... more
Prof. Dr. Viktoria Däschlein-Gessner
Viktoria Däschlein-Gessner, born in 1982, studied chemistry at Marburg and Würzburg universities and received her doctorate from the Technical University Dortmund in 2009. After a postdoctoral stay at the University of California in Berkeley, she headed an Emmy Noether junior research group ... more
Kevin Wonner, born in 1995, studied chemistry with the focus on electrochemical nanoparticle characterization at the Ruhr University Bochum. He started his PhD in 2018 at the chair of Analytical Chemistry II of Professor Dr. Kristina Tschulik and is supported by the graduate school 2376. Hi ... more
Quickly identify high-performance multi-element catalysts
Finding the best material composition among thousands of possibilities is like looking for a needle in a haystack. An international team is combining computer simulations and high-throughput experiments to do this. Catalysts consisting of at least five chemical elements could be the key to ... more
Malaria pathogens under the X-ray microscope
Malaria is one of the most threatening infectious diseases in the world. An international team has now been able to investigate malaria pathogens in red blood cells in vivo using the BESSY II X-ray microscope and the ALBA and ESRF synchrotron sources. The scientists reveal the mechanisms us ... more
New discoveries map out CRISPR-Cas defence systems in bacteria
With the aid of highly advanced microscopes and synchrotron sources, researchers from the University of Copenhagen have gained seminal insight into how bacteria function as defence mechanisms against attacks from other bacteria and viruses. The study, which has just been published in the jo ... more
The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.
> more about q&more
q&more is supported by:
