HZB Newsroom

MXenes are adept at hosting catalytically active particles. This property can be exploited to create more potent catalyst materials that significantly accelerate and enhance the oxygen evolution reaction, which is one of the bottlenecks in the production of green hydrogen via electrolysis using solar or wind power. A detailed study by an international team led by HZB chemist Michelle Browne shows the potential of these new materials for future large-scale applications. The study is published in Advanced Functional Materials.

The South African chemist Denzil Moodley is the first Industrial Research Fellow at HZB. He is playing a leading role in the CARE-O-SENE project. The Fellowship program aims to further accelerate the development of an efficient catalyst for a sustainable aviation fuel. An interview about the CARE-O-SENE project and why it is so important for scientists from industry and public research to work together.

A new instrument is now available at BESSY II for investigating catalyst materials, battery electrodes and other energy devices under operating conditions: the Operando Absorption and Emission Spectroscopy on EMIL (OÆSE) endstation in the Energy Materials In-situ Laboratory Berlin (EMIL). A team led by Raul Garcia-Diez and Marcus Bär showcases the instrument’s capabilities via a proof-of-concept study on electrodeposited copper.

Clathrates are characterised by a complex cage structure that provides space for guest ions too. Now, for the first time, a team has investigated the suitability of clathrates as catalysts for electrolytic hydrogen production with impressive results: the clathrate sample was even more efficient and robust than currently used nickel-based catalysts. They also found a reason for this enhanced performance. Measurements at BESSY II showed that the clathrates undergo structural changes during the catalytic reaction: the three-dimensional cage structure decays into ultra-thin nanosheets that allow maximum contact with active catalytic centres. The study has been published in the journal ‘Angewandte Chemie’.

Contrary to what we learned at school, some catalysts do change during the reaction: for example, certain electrocatalysts can change their structure and composition during the reaction when an electric field is applied. The X-ray microscope TXM at BESSY II in Berlin is a unique tool for studying such changes in detail. The results help to develop innovative catalysts for a wide range of applications. One example was recently published in Nature Materials. It involved the synthesis of ammonia from waste nitrates.

Dr. Moses Alfred Oladele is working on photocatalysis for CO₂ conversion in a joint project with the group of Dr. Matt Mayer, HZB, and Prof. Andreas Taubert at the University of Potsdam. The chemist from Redeemer's University in Ede, Nigeria, came to Berlin in the summer of 2024 with a Georg Forster Research Fellowship from the Alexander von Humboldt Foundation and will work at HZB for two years.

Michelle Browne heads a Helmholtz Young Investigators Group on electrocatalysis at HZB. She has now been selected as a fellow of the Daimler and Benz Foundation. She will receive 40,000 euros over the next two years and, in addition, access to an excellent research network.

In a small manganese oxide cluster, teams from HZB and HU Berlin have discovered a particularly exciting compound: two high spin manganese centres in two very different oxidation states and. This complex is the simplest model of a catalyst that occurs as a slightly larger cluster in natural photosynthesis, where it enables the formation of molecular oxygen. The discovery is considered an important step towards a complete understanding of photosynthesis.

Within the CARE-O-SENE project, HZB is cooperating with the South African company Sasol on innovative catalysts for sustainable aviation fuels (SAF). Now, the collaboration is intensifying: Dr. Denzil Moodley, a leading scientist in the field of Fischer-Tropsch at Sasol Research and Technology, is being appointed as Industrial Research Fellow at HZB. Moodley will contribute his expertise at HZB with the aim of accelerating the innovation cycle for sustainable fuel technologies.

A novel catalyst platform, known as Laterally Condensed Catalysts (LCC), has been developed to enable design and analysis of the functional interface connecting the active mass to its support. This interface not only influences the chemical properties of the reactive interface but also controls its stability and hence the sustainability of the catalytic materials. The development was significantly supported by the use of operando spectroscopy at the BESSY II synchrotron, which made it possible to observe and understand the dynamic processes and structures under reaction conditions.

The development of efficient catalysts for the Oxygen Evolution Reaction (OER) is crucial for advancing Proton Exchange Membrane (PEM) water electrolysis, with iridium-based OER catalysts showing promise despite the challenges related to their dissolution. Collaborative research by the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH and the Fritz-Haber-Institut has provided insights into the mechanisms of OER performance and iridium dissolution for amorphous hydrous iridium oxides, advancing the understanding of this critical process.

Iridium-based catalysts are needed to produce hydrogen using water electrolysis. Now, a team at HZB has shown that the newly developed P2X catalyst, which requires only a quarter of the Iridium, is as efficient and stable over time as the best commercial catalyst. Measurements at the EMIL lab at BESSY II have now revealed how the special chemical environment in the P2X catalyst during electrolysis promotes the oxygen evolution reaction during water splitting.

A team from the Technical University of Berlin, HZB, IMTEK (University of Freiburg) and Siemens Energy has developed a highly efficient alkaline membrane electrolyser that approaches the performance of established PEM electrolysers. What makes this achievement remarkable is the use of inexpensive nickel compounds for the anode catalyst, replacing costly and rare iridium. At BESSY II, the team was able to elucidate the catalytic processes in detail using operando measurements, and a theory team (USA, Singapore) provided a consistent molecular description. In Freiburg, prototype cells were built using a new coating process and tested in operation. The results have been published in the prestigious journal Nature Catalysis.

The MXene class of materials has many talents. An international team led by HZB chemist Michelle Browne has now demonstrated that MXenes, properly functionalised, are excellent catalysts for the oxygen evolution reaction in electrolytic water splitting. They are more stable and efficient than the best metal oxide catalysts currently available. The team is now extensively characterising these MXene catalysts for water splitting at the Berlin X-ray source BESSY II and Soleil Synchrotron in France.

At first glance, the plan sounds compelling: invent and develop future electrolysers capable of producing hydrogen directly from unpurified seawater. But a closer look reveals that such direct seawater electrolysers would require years of high-end research. And what is more: DSE electrolyzers are not even necessary - a simple desalination process is sufficient to prepare seawater for conventional electrolyzers. In a commentary in Joule, international experts compare the costs and benefits of the different approaches and come to a clear recommendation.