Swiss Light Source (SLS) – Lightsources.org

International Day of Light #LightSourceSelfie special from the SLS

2023/05/162023/05/18

A community driven by curiosity!

To celebrate International Day of Light 2023, we bring you a #LightSourceSelfies special (see below) from Ludmila Leroy, a postdoc at the Swiss Light Source (SLS), which is located at the Paul Scherrer Institut (PSI) in Villigen, Switzerland. With an energy of 2.4 GeV, the SLS provides photon beams of high brightness for research in materials science, biology and chemistry.

Ludmila, who is from Brazil, is studying the properties of magnetic materials. She highlights the versatility of light sources as hugely advantageous to science and learning from, and about, nature. “We are all driven by curiosity and these versatile facilities gives us the ability to try different approaches and push the boundaries in our experiments.” Looking back on her career to date, Ludmila would advise her younger self “not to be scared to reach out for the world” as there are many light sources facilities around the globe and travelling to different countries is an exciting part of being a scientist.

As with all light sources, the SLS operates around the clock and Ludmila has a new take on making night shifts more bearable. Throughout the #LightSourceSelfie campaign, most participants have mentioned coffee, chocolate or candy when talking about night shift survival strategies. For Ludmila, night shifts are more bearable when she eats healthily and makes sure that she keeps hydrated.

And when she is not at a light source….Ludmila is in charge of the Music Club at PSI, which brings together a mixture of PhD students, postdocs, technicians and staff scientists. The PSIchedelics is just one of the society’s musical entertainment offerings. Ludmila plays the bass and sings in this band and her #LightSourceSelfie ends with a fantastic clip of them in action. You can find out more about music at PSI here: Music at PSI | Our Research | Paul Scherrer Institut (PSI)

X-rays look at nuclear fuel cladding with new detail

2023/05/112023/05/24

Micro-beam measurements at the Swiss Light Source SLS have enabled insights into the crystal structure of hydrides that promote cracks in nuclear fuel cladding. This fundamental knowledge of the material properties of cladding will help assess safety during storage.

For over seventy years, zirconium alloys have been used as cladding for nuclear fuel rods. This cladding provides a structural support for the nuclear fuel pellets and an initial barrier to stop fission products escaping into the reactor water during operation. During its long history, which includes extensive research and development advances, reactor type zirconium alloys have proved themselves as an extremely successful material for this application.

Yet they have a well-known nemesis: hydrogen. When submerged in water during operation in a reactor, at the hot surface of the fuel rod water molecules split into hydrogen and oxygen. Some of this hydrogen then diffuses into the cladding. It makes its way through the cladding until – when the concentration and conditions are right – it precipitates to form chemical compounds known as zirconium-hydrides. These hydrides make the material brittle and prone to cracking. Now, using the Swiss Light Source SLS, researchers were able to shed new light on the interplay between cracking and hydride formation.

Using a technique called synchrotron micro-beam X-ray diffraction, the researchers could study the structure of hydrides during the growth of cracks in fuel cladding at a new level of detail. “Through thermomechanical tests, we could control extremely slow crack propagations. Discovering at such high spatial resolution which hydride formations actually occurred made all the challenges of the material preparation worthwhile,” says study first author, Aaron Colldeweih who designed the thermomechanical testing procedure as part of his PhD project at PSI.

One of the things they discovered was that an unexpected type of hydride was present at the crack tip. This type of hydride, known as gamma-hydride has a slightly different crystal structure and stoichiometry to the type more commonly present, known as delta-hydride, “There has been a lot of discussion about gamma-hydrides: whether they are stable and whether they exist at all. Here we could show that with certain applied stresses you create gamma-hydrides that are stable,” says Johannes Bertsch, who leads the Nuclear Fuels Group in the Laboratory of Nuclear Materials at PSI.

Image: Malgorzata Makowska, scientist at the MicroXAS beamline of the SLS, carefully positions a standard material for setup calibration on the sample manipulator in front of the X-ray beam.

Credit: Paul Scherrer Institute / Mahir Dzambegovic

Laura Heyderman elected Royal Society Fellow

2023/05/102023/05/11

Today, the announcement was made that Laura Heyderman, who leads the Mesoscopic Systems Group at PSI, has been elected Fellow of the Royal Society (FRS). Laura’s nomination recognises almost 30 years of research into magnetic materials and magnetism on the nanoscale, most notably, in the field of artificial spin ice.

Laura Heyderman is best known for her breakthroughs with nanomagnets – minute bar magnets that are a few hundreds of times smaller than the width of a human hair. Her research group, shared between Paul Scherrer Institute PSI and ETH Zurich where she became full professor in 2013, use these to create elaborate structures and devices. With the help of the large research infrastructures at PSI (X-rays, muons and neutrons) they then investigate the novel phenomena that they exhibit. The tiny magnetic systems they create can have a range of technological applications, such as for computation, communication, sensors or actuators.

Image: Laura Heyderman began working on magnetism as a PhD student investigating magnetic thin films in Paris in 1988. Today, she leads the Mesoscopic Systems Group, shared between PSI and ETH where she is a full professor.

Credit: ETH Zurich / Giulia Marthaler

Cement hydration in 4D: towards a reduction in emissions

2023/05/102023/05/11

Researchers led by the University of Málaga show the Portland cement early age hydration with microscopic detail and high contrast between the components. This knowledge may contribute to more environmentally friendly cements. The results are now published in Nature Communications.

Concrete is a fluid mass that strikingly sets and hardens in hours, even under water. This fabricated rock, which is made of cement, water, sand and gravel, is the basic building block of our civilization. Hence, it is not a surprise that it is the world’s largest manufactured commodity. The enormous production of Portland cement (PC), at 4 billion tonnes per year, results in 2.7 billion tonnes of CO2 emissions per year. If cement production were considered a country, it would be the third CO2 emitter in the world, just after China and USA. Therefore, reducing the CO2 footprint of cement, mortar and concrete is a societal need.

The main drawback of the current proposals for low-carbon cements is the slow hydration kinetics in the first 3 days. “Understanding the processes related to cement hydration as it takes place at its early stages is crucial”, explains Shiva Shirani, first author of the paper and PhD student at the University of Malaga. Despite a century of research, our understanding of cement dissolution and precipitation processes at early ages is very limited. “So we have developed a methodology to get a full picture of the hydration of Portland cement”, she adds.

The team, which is led by the University of Málaga and includes the ESRF, the Paul Scherrer Institute PSI (Switzerland) and the University Grenoble Alpes (France), carried out a tomographic study in the laboratory for an initial characterisation, followed by phase-contrast microtomography experiments with synchrotron radiation to take data very quickly and in large sample volumes, and finally experiments at the nanometric scale, using synchrotron ptychotomography.

Image: Scientists followed the hydration process of cement in its early stages

Credit: Shiva Shirani

Always on the pulse of time

2023/04/122023/04/18

On 1 January 2023, the Paul Scherrer Institute PSI turned 35. And these past 35 years have been very eventful. Some of those events have to do with the development and the history of the Institute: new large research facilities have been added; proton therapy has become increasingly important; the spin-offs created at PSI and the licensing agreements concluded were also important. Most recently, the focus has been on exploring quantum physics and using it in practical applications. Another group of events has to do with research itself, with the history of science at PSI. These are about research and research results that are not only, but to a large extent, related to the unique large research facilities available at PSI.

Image: 1988: Foundation of the Paul Scherrer Institute PSI

X-rays make 3D metal printing more predictable

2023/04/112023/04/20

Insights into the microscopic details of 3D printing gained using the microXAS beamline of the Swiss Light Source SLS could propel the technology toward wider application.

Researchers have not yet gotten the additive manufacturing, or 3D printing, of metals down to a science completely. Gaps in our understanding of what happens within metal during the process have made results inconsistent. But new research could grant a greater level of mastery over metal 3D printing.

Using powerful x-rays generated by the Swiss Light Source SLS and Argonne National Laboratory’s Advanced Photon Source, researchers at Paul Scherrer Institute PSI, the National Institute of Standards and Technology (NIST), KTH Royal Institute of Technology in Sweden and other institutions have peered into the internal structure of steel as it was melted and then solidified during 3D printing. The findings, published in Acta Materialia, unlock a computational tool for 3D-printing professionals, offering them a greater ability to predict and control the characteristics of printed parts, potentially improving the technology’s consistency and feasibility for large-scale manufacturing.

“So-called operando measurements with x-rays enable us to capture what is really happening to the microstructure during a rapid process such as printing.” said Steven Van Petegem, senior scientist at PSI, who led the experimental work performed at the SLS using the microXAS beamline.

Image: Researchers used high-speed X-ray diffraction to identify the crystal structures that form within steel as it is 3D-printed. The angle at which the X-rays exit the metal correspond to types of crystal structures within.

Credit: H. König et al. via Creative Commons (https://creativecommons.org/licenses/by/4.0), adapted by N. Hanacek/NIST

How football-shaped molecules occur in the universe

2023/03/272023/04/03

For a long time it has been suspected that fullerene and its derivatives could form naturally in the universe. These are large carbon molecules shaped like a football, salad bowl or nanotube. An international team of researchers using the Swiss SLS synchrotron light source at PSI has shown how this reaction works. The results have just been published in the journal Nature Communications.

“We are stardust, we are golden. We are billion-year-old carbon.” In the song they performed at Woodstock, the US group Crosby, Stills, Nash & Young summarised what humans are essentially made of: star dust. Anyone with a little knowledge of astronomy can confirm the words of the cult American band – both the planets and we humans are actually made up of dust from burnt-out supernovae and carbon compounds billions of years old. The universe is a giant reactor and understanding these reactions means understanding the origins and development of the universe – and where humans come from.

In the past, the formation of fullerenes and their derivatives in the universe has been a puzzle. These carbon molecules, in the shape of a football, bowl or small tube, were first created in the laboratory in the 1980s. In 2010 the infrared space telescope Spitzer discovered the C₆₀ molecules with the characteristic shape of a soccer ball, known as buckyballs, in the planetary nebula Tc 1. They are therefore the biggest molecules to have been discovered to date known to exist in the universe beyond our solar system.

But how do they actually form there? A team of researchers from Honolulu (USA), Miami (USA) and Tianjin (China) has now completed an important reaction step in the formation of the molecules, with active support from PSI and the vacuum ultraviolet (VUV) beamline of the synchrotron light source Swiss SLS. “PSI offers unique experimental facilities and that’s why we decided to collaborate with Patrick Hemberger at PSI,” says Ralf Kaiser from the University of Hawaii in Honolulu, the leading international researcher in this field.

Credit: Shane Goettl/Ralf I. Kaiser

Using light to switch drugs on and off

2023/03/202023/04/03

Scientists at the Paul Scherrer Institute PSI have used the Swiss X-ray free-electron laser SwissFEL and the Swiss Light Source SLS to make a film that could give a decisive boost to developing a new type of drug. They made the advance in the field of so-called photopharmacology, a discipline that develops active substances which can be specifically activated or deactivated with the help of light. The study is being published today in the journal Nature Communications.

Photopharmacology is a new field of medicine that is predicted to have a great future. It could help to treat diseases such as cancer even more effectively than before. Photopharmacological drugs are fitted with a molecular photoswitch. The substance is activated by a pulse of light, but only once it has reached the region of the body where it is meant to act. And after it has done its job, it can be switched off again by another pulse of light.

This could limit potential side effects and reduce the development of drug resistance – to antibiotics, for example.

Licht-switchable drugs

To make conventional drugs sensitive to light, a switch is built into them. In their study, the scientists led by the principal authors Maximilian Wranik and Jörg Standfuss used the active molecule combretastatin A-4, which is currently being tested in clinical trials as an anti-cancer drug. It binds to a protein called tubulin, which forms the microtubules that make up the basic structure of the cells in the body, and also drive cell division. Combretastatin A-4, or “CA4” for short, destabilises these microtubules, thereby curbing the uncontrolled division of cancer cells, i.e. it slows down the growth of tumours.

In the modified CA4 molecule, a bridge consisting of two nitrogen atoms is added, which makes it particularly photoactive. In the inactive state, the so-called azo bridge stretches the molecular components to which it is attached to form an elongated chain. The pulse of light bends the bond, bringing the ends of the chain closer together – like a muscle contracting to bend a joint. Crucially, in its elongated form, the molecule does not fit inside the binding pockets of the tubulin – depressions on the surface of the protein where the molecule can dock in order to exert its effect. However, when the molecule is bent, it fits perfectly – like a key in a lock. Molecules like this, which fit into corresponding binding pockets, are also called ligands.

Image: Jörg Standfuss (left) and Maximilian Wranik in front of the experimental station Alvra of the Swiss X-ray free-electron laser SwissFEL, where the photopharmacological studies were carried out. In the long term, the aim is to develop drugs that can be switched on and off by light.

Credit: Paul Scherrer Institute/Markus Fischer

A star is born

2023/02/212023/03/06

Swiss Light Source SLS reveals complex chemistry inside ‘stellar nurseries’

An international team of researchers has uncovered what might be a critical step in the chemical evolution of molecules in cosmic “stellar nurseries.” In these vast clouds of cold gas and dust in space, trillions of molecules swirl together over millions of years. The collapse of these interstellar clouds eventually gives rise to young stars and planets.

Like human bodies, stellar nurseries contain a lot of organic molecules, which are made up mostly of carbon and hydrogen atoms. The group’s results, published in the journal Nature Astronomy, reveal how certain large organic molecules may form inside these clouds. It’s one tiny step in the eons-long chemical journey that carbon atoms undergo—forming in the hearts of dying stars, then becoming part of planets, living organisms on Earth and perhaps beyond.

“In these cold molecular clouds, you’re creating the first building blocks that will, in the end, form stars and planets,” said Jordy Bouwman, research associate at the Laboratory for Atmospheric and Space Physics (LASP) and assistant professor in the Department of Chemistry at University Colorado Boulder.

For the new study, Bouwman and his colleagues took a deep dive into one stellar nursery in particular: the Taurus Molecular Cloud (TMC-1). This region sits in the constellation Taurus and is roughly 440 light years (more than 2 quadrillion miles) from Earth. The chemically complex environment is an example of what astronomers call an “accreting starless core.” Its cloud has begun to collapse, but scientists haven’t yet detected embryonic stars emerging inside it.

Image: Using PEPICO spectroscopy at the SLS, researchers discovered how hexagonally-shaped ortho-benzyne molecules can combine with methyl radicals to form a series of larger organic molecules, each containing a ring of five carbon atoms.

Credit: Henry Cardwell

#SynchroLightAt75 – Grating interferometry and phase-contrast imaging

2022/12/212023/01/05

The development of X-ray phase-contrast imaging at Paul Scherrer Institute PSI tells a story of how basic research can quickly lead to practical applications. Grating interferometry was pioneered by PSI scientists as a technique for characterizing the X-ray wave front at synchrotron sources, such as the Swiss Light Source SLS. This development enhanced the quality of X-ray images. Soon after, it began to be used for phase-contrast imaging of soft matter-like tissue, and was subsequently brought to X-ray lab sources as well. Currently, it is under development for mammography with improved contrast for soft tissue and the micro-calcifications that are markers for benign and malignant tissue alterations.

Read more about this development via these links: Phase contrast improves mammography and Phase-contrast X-ray imaging for advanced breast cancer detection

Image: Marco Stampanoni pioneered the technique of phase-contrast X-ray imaging, which enables higher resolution mammograms that can help detect breast cancer earlier

Credit: Paul Scherrer Institute / Markus Fischer

#SyncroLightAt75 – Structure of the Ribosome

2022/12/012022/12/06

Along with Ada Yonath and Thomas Steitz,Venkatraman Ramakrishnan from the MRC Laboratory of Molecular Biology in Cambridge, UK was awarded the 2009 Nobel Prize in Chemistry for determining the structure of the ribosome, one of the largest and most important molecules in the cell. X-ray crystallography experiments that enabled elucidation of the ribosome structure used synchrotron light from a number of light sources worldwide, each with unique capabilities, including the Swiss Light Source SLS.

Image: Interior view of the experimental hall at the Swiss Light Source SLS

Credit: Photo: H.R. Bramaz/PSI

Nanomaterial from the Middle Ages

2022/10/102022/10/26

To gild sculptures in the late Middle Ages, artists often applied ultra-thin gold foil supported by a silver base layer. For the first time, scientists at the Paul Scherrer Institute PSI have managed to produce nanoscale 3D images of this material, known as Zwischgold. The pictures show this was a highly sophisticated mediaeval production technique and demonstrate why restoring such precious gilded artefacts is so difficult.

The samples examined at the Swiss Light Source SLS using one of the most advanced microscopy methods were unusual even for the highly experienced PSI team: minute samples of materials taken from an altar and wooden statues originating from the fifteenth century. The altar is thought to have been made around 1420 in Southern Germany and stood for a long time in a mountain chapel on Alp Leiggern in the Swiss canton of Valais. Today it is on display at the Swiss National Museum (Landesmuseum Zürich). In the middle you can see Mary cradling Baby Jesus. The material sample was taken from a fold in the Virgin Mary’s robe. The tiny samples from the other two mediaeval structures were supplied by Basel Historical Museum.

The material was used to gild the sacred figures. It is not actually gold leaf, but a special double-sided foil of gold and silver where the gold can be ultra-thin because it is supported by the silver base. This material, known as Zwischgold (part-gold) was significantly cheaper than using pure gold leaf. “Although Zwischgold was frequently used in the Middle Ages, very little was known about this material up to now,” says PSI physicist Benjamin Watts: “So we wanted to investigate the samples using 3D technology which can visualise extremely fine details.” Although other microscopy techniques had been used previously to examine Zwischgold, they only provided a 2D cross-section through the material. In other words, it was only possible to view the surface of the cut segment, rather than looking inside the material. The scientists were also worried that cutting through it may have changed the structure of the sample. The advanced microscopy imaging method used today, ptychographic tomography, provides a 3D image of Zwischgold’s exact composition for the first time.

Image: The altar examined is thought to have been made around 1420 in Southern Germany and for a long time stood in a mountain chapel on Alp Leiggern in the Swiss canton of Valais. Today it is on display at the Swiss National Museum (Landesmuseum Zürich).

Credit: Swiss National Museum, Landesmuseum Zürich

Three research facilities reveal magnetic crossover

2022/09/122022/09/21

Spins tick-tock like a grandfather clock and then stop. Thanks to complementary experiments at the Swiss Muon Source SµS, Swiss Spallation Neutron Source SINQ and the Swiss Light Source SLS, researchers led by the University of Geneva have discovered this coveted characteristic, known as magnetic crossover, hidden within the magnetic landscape of an exotic layered material. Magnetic crossover means tuneability and with it promise for spin-based electronics.

A two-dimensional layered material that is magnetic and a small band gap semiconductor? For the electronics of tomorrow, you could say that Chromium Sulfide Bromide (CrSBr) has it all. “Any new magnetic features that you can find in the material can be useful from a practical point of view”, says Zurab Guguchia, scientist in muon spin spectroscopy at PSI. Together with clues from two other of PSI’s large research facilities, this technique would reveal the highly sought-after trait of magnetic crossover in this exciting new material.

The researchers discovered that as CrSBr is cooled, magnetic fluctuations in the material – where the spins tick-tock back and forth like a grandfather clock – slow down and then freeze. This process is known as magnetic crossover. Interestingly, this is a gradual ‘crossover’ from one state to another, rather than a sharp transition that occurs at one temperature. And it is this characteristic that makes it such an appealing characteristic for spin based electronics devices, as Guguchia explains:

“We believe that this dynamic magnetic behaviour comes from competing interactions and frustrations that exist between the layers in the material. This means, with an external parameter we could tune it: push it in either direction. You couldn’t do this if it was just in one boring state.”

Image: To discover the hidden order within CrSBr’s magnetic structure, researchers needed complementary evidence from three different facilities: the Swiss Muon Source, the Swiss Spallation Neutron Source and the Swiss Light Source. With these techniques, they could reveal that spin fluctuations dwindled and then froze at 40 degrees Kelvin

Credit: Paul Scherrer Institute / Mahir Dzambegovic

A piece of PSI history sets off on a long journey

2022/09/082022/09/27

Safely packed in a sturdy wooden crate, a high-tech component from PSI has begun its journey to Australia. The device was in use at PSI for more than ten years – now, with the commissioning of the Swiss X-ray free-electron laser SwissFEL, it has reached the end of its service life and will be given a new task at the Australian Synchrotron in Melbourne.

The device is carefully lifted by the indoor crane. The weight displayed on the crane’s external screen shoots up and down, eventually settling down at about 11.5 tonnes. The weight of this so-called insertion device is mainly due to its heavy steel frame. The magnets installed inside this generate attractive forces of several tonnes. The device must be able to withstand this enormous field strength. In particle accelerators, the periodic arrangement of the magnets is used to deflect electrons, thereby generating synchrotron radiation – a special type of X-rays.

Pioneering work at PSI

At PSI, the insertion device was used for a very special purpose, however. Following a lecture by an American colleague on the generation of ultra-short X-ray pulses, the two PSI physicists Gerhard Ingold and Thomas Schmidt realised that the conditions at the Swiss Light Source SLS were ideal for such a technique. The technology is called femtoslicing, and it can be used to observe extremely fast processes, such as chemical reactions.

“Immediately after the lecture was over, we did our first calculations. A few days later, the calculations turned into a project and three years later, under the leadership of Gerhard Ingold, we were finally able to produce hard X-rays in the femtosecond range for the first time in the world – a pulse of high-energy X-rays lasting 0.000 000 000 000 1 second,” as the head of the Insertion Device Group at PSI, Thomas Schmidt, recalls. Their approach was based on using the powerful magnetic field produced by this device as a modulator, so as to achieve resonance between the electrons and an external infrared laser, thereby transferring the pulse length of the latter to the X-rays. Since only a small fraction of the electrons are used in this process, namely those that overlap with the laser pulse, the technique is referred to as “slicing”.

The project resulted in numerous publications. Experiments were carried out on a range of different samples and new types of detectors were developed in order to process the extremely fast units of information. These findings were ultimately crucial to the development of free electron lasers, which are driven by linear accelerators and thus indirectly also the Swiss X-ray free-electron laser SwissFEL, where the first pilot experiments were carried out in 2017. However, this also heralded the end of the Femtoslicing Facility and thus of the insertion device in question. “SwissFEL allows us to generate much brighter and even shorter pulses of this kind of radiation than with the original facility. With this, extremely fast processes can be imaged at even higher resolutions,” says Thomas Schmidt.

Since then, the insertion device has been sitting in the hall of the SLS, unused.

Important manufacturer based in Siberia

Insertion devices are high-precision instruments, and demand for them is limited. Because of this, only a few manufacturers in the world are prepared to take on the complex task of building these devices in the first place. The world’s most important supplier of superconducting wigglers (a special type of insertion device) is based in Russia. However, due to the war and the global sanctions against Russia, many countries have also stopped importing these rare devices.

“Suddenly, there was a demand for retired wigglers in our European network for synchrotron radiation sources (LEAPS – League of European Accelerator-based Photon Sources),” explains Thomas Schmidt. “First, SOLARIS, the National Synchrotron Radiation Centre in Poland, inquired about a device that was no longer needed – we immediately agreed and sent them the plans. Unfortunately, our device was not compatible with their facility.” But just a short while later, the Australian Nuclear Science and Technology Organisation got in touch, also asking for a wiggler for their synchrotron in Melbourne. Again plans were sent – and this time everything fitted.

Image: Thomas Schmidt in the hall of the Swiss Light Source SLS. The insertion device weighing several tonnes can be seen suspended in the background, ready for transport. After being used for research at PSI more than ten years, this high-tech device will be given a new home at the Australian Synchrotron in Melbourne.

Credit: Paul Scherrer Institute/Mahir Dzambegovic

Weird fossil is not our ancestor

2022/08/172022/08/25

It has recently been supposed that humans could trace their ancestry back to a strange microscopic creature with a mouth and no anus. Thanks to analysis of 500 million year old fossils at the Swiss Light Source SLS, we can be relieved to find out this is not true: Saccorhytus is not a deuterostome like us, but an ecdysozoan. The findings, published today in Nature, make important amendments to the early phylogenetic tree and our understanding of how life developed.

In 535 million year old rocks in China is a mysterious microfossil whose evolutionary affinity is hotly debated. Saccorhytus was originally described in 2017 as an ancestral deuterostome, a member of the group from which our own deep ancestors emerged. It is microscopic in size – about a millimetre in diameter – and resembles a spikey, wrinkly sack, with a mouth surrounded by spines and holes that were interpreted as pores for gills – a primitive feature of the group. This made for a very unexpected origin of deuterostomes: within sand-grain sized organisms that may have lived among the sand or floating in the sea. However, the evidence supporting this view was always very weak – were those holes around the mouth really gill pores?

The researchers tried to address this question by collecting new specimens of Saccorhytus, dissolving tonnes of rock with strong vinegar and picking through the resulting grains of sand for these rare fossils. The fossils are no longer rare – the teams recovered hundreds of specimens, many much better preserved than any seen before, providing new insights into the anatomy and evolutionary affinity of Saccorhytus.

“Some of the fossils are so perfectly preserved that they look almost alive,” says Yunhuan Liu, professor in Palaeobiology at Chang’an University, Xi’an, China. “Saccorhytus was a curious beast, with a mouth but no anus, and rings of complex spines around its mouth.”

Image: The reconstructions show the fossil of Saccorhytus from the front

Credit: Graphic: Dinghua Yang

Reaction insights help make sustainable liquid fuels

2022/06/272022/07/07

Methanol, produced from carbon dioxide in the air, can be used to make carbon neutral fuels. But to do this, the mechanism by which methanol is turned into liquid hydrocarbons must be better understood so that the catalytic process can be optimised. Now, using sophisticated analytical techniques, researchers from ETH Zürich and Paul Scherrer Institute have gained unprecedented insight into this complex mechanism.

As we struggle to juggle the impact of emissions with our desire to maintain our energy hungry lifestyle, using carbon dioxide in the atmosphere to create new fuels is an exciting, carbon neutral alternative. One way to do this is to create methanol from carbon dioxide in the air, using a process called hydrogenation. This methanol can then be converted into hydrocarbons. Although these are then burnt, releasing carbon dioxide, this is balanced by carbon dioxide captured to make the fuel.

To fully develop this sustainable fuel, a deeper understanding of the mechanism by which methanol – in a reaction catalysed by zeolites, solid materials with unique porous architectures – is turned into long chain hydrocarbons, is necessary. With this in mind, in the frame of NCCR Catalysis, a Swiss National Center of Competence in Research, researchers from ETH Zürich joined forces with researchers from the Paul Scherrer Institut PSI to reveal the details of this reaction mechanism, the findings of which are published in the journal Nature Catalysis.

“Information is key to developing more selective and stable catalysts,” explains Javier Pérez-Ramírez, Professor of Catalysis Engineering at ETH Zürich and director of NCCR Catalysis, who co-led the study. “Prior to our study, despite many efforts, key mechanistic aspects of the complex transformation of methanol into hydrocarbons were not well understood”.

The researchers were interested in comparing the methanol to hydrocarbon process with another process: that of turning methyl chloride into hydrocarbons. Oil refineries frequently burn large quantities of unwanted methane rich natural gas. This polluting and wasteful activity results in the typical flares associated with oil refineries. “Turning methyl chloride into hydrocarbons is a kind of bridge technology,” explains Pérez-Ramírez. “Of course, we would like to move away from fossil fuels but in the meantime this would be a way to avoid wasting the vast reserves of valuable methane”.

Image: Researchers (L to R) Javier Pérez-Ramírez, András Bödi and Patrck Hemberger at the Swiss Light Source SLS

Credit: Paul Scherrer Institute / Markus Fischer