Catalysis research with synchrotron radiation

© Dr. Ziliang Chen/HZB

Wedding Agents

Countless products in our daily lives are produced through chemical reactions, for example medicines, cosmetics, fertilisers and plastics. The necessary reactions do not run efficiently on their own, but need support. For this purpose, substances are used that influence the reaction rate of a chemical reaction without being consumed themselves - they act like a "matchmaker" who discreetly withdraws again after bringing the two partners together for the "marriage". Such catalysts help to save energy in all areas, but they also enable reactions that we need directly for the energy transition.

Conversion of renewable energies

For the energy transition, the intermediate storage of energy is crucial, as electricity from wind and sun cannot be generated continuously. Batteries require large amounts of raw materials, such as lithium and cobalt, so for many applications intermediate storage in electrocatalytically produced green hydrogen, for the production of which only water is needed, is an option. In addition, catalytic processes can bind CO2 and convert it into important raw materials.

Research goals

Catalysts used in processes that are important for the energy transition are often still unstable and expensive. Often, the energy efficiency of the processes is also still too low to serve as a sensible solution. This is where synchrotron radiation comes in handy, an extremely intense radiation up into the X-ray range that can be used to observe processes on the catalyst surface during operation with atomic resolution. The results thus obtained then help to understand, for example, why a catalyst wears out during the reaction and how this can be prevented with new materials.

Catalytic reactions

Catalytic processes that are important for the energy transition are, for example, the electrochemical electrolysis of hydrogen and various power-to-X processes. In hydrogen electrolysis, electricity (preferably from renewable energies) is used to split water into hydrogen and oxygen. The hydrogen can then be stored and later converted back into electricity in fuel cells. In power-to-X processes, the hydrogen produced here can also be further reacted with the climate gas CO2. This results in a wide variety of products for the chemical industry, electric fuels with which combustion engines can continue to be operated in a climate-neutral manner.

Catalysis research with synchrotron radiation

Synchrotron radiation sources are large-scale research facilities such as storage rings or free-electron lasers in which charged particles accelerated to almost the speed of light emit photons, intense light (synchrotron radiation).

Since 2018, the "CatAct" measurement line at the KIT synchrotron has allowed the combination of catalytic reactions for the production of hydrogen or CO2 reduction with operando X-ray absorption spectroscopy. Highlights were, for example, the production of synthetic fuels at 30 bar or CO2 methanation under dynamic conditions. Thus, the CatAct measuring line is already building a bridge to industry. The new catalysis research platform "CatLab" in Berlin-Adlershof, which HZB and the MPG have been jointly building and operating since December 2020, is also intended to serve this goal. Here, chemical conversion processes based on novel customised (chemo, electro and photo) catalysts are to be developed on an industrial scale.

Basic research on catalysis is currently bundled, for example, in the priority programme SPP2080 "Catalysts and reactors under dynamic operating conditions for energy storage and conversion", in which research is being conducted, among other things, on reactivating catalysts in quiescent phases and increasing the yield of the desired reaction products. Many groups in SPP2080 use synchrotron radiation, as does KIT's DFG Collaborative Research Centre "TrackAct - Tracking Active Centres in Heterogeneous Catalysts for Emission Control".

"Today, the chemical industry still uses almost entirely fossil raw materials for the production of chemical products. Converting this to renewable ones is a major challenge. Synchrotron radiation is a unique key to this, because it allows us to observe how the catalysts needed for this work - "operando" in technical jargon. Only in this way can materials be developed in a targeted and efficient manner and create a basis for computer-aided design," says Prof. Jan-Dierk Grunwaldt, KFS chairman and himself involved as a researcher at KIT in the conversion of wind and solar energy or biomass into chemical products.

Examples from research

In order to tailor optimise catalysts for the desired application, one must know their properties and understand their function. Moreover, it is not only about efficiency, but also about cost savings, sustainability and stability. In the most widely used type of electrolysis, PEM electrolysis, for example, the very rare and expensive metal iridium is used, which costs up to 40 times as much as gold. In recent years, it has been possible to significantly reduce the amount of iridium. In the following, examples are listed that show what insights synchrotron radiation offers and how these help to improve catalysis.

Green hydrogen: faster progress with modern X-ray sources, HZB, 07 October 2022

Three Eyes See More than Two, HZB/TU Wien and FHI Berlin, 28 September 2022

European Young Chemists’ Award for Sebastian Weber, EYCA, 26 September 2022

On the way to Green Ammonia, Max-Planck-Institut für Kohlenforschung / DESY, 19 September 2022

Green hydrogen: Nanostructured nickel silicide shines as a catalyst, TU Berlin / FU Berlin / HZB, 11 August 2022

Live view into catalyst materials, DESY / KIT, 06 April 2022

Molecule snapshot by explosion, European XFEL / DESY, Univ. Frankfurt et al., 21 February 2022

Innovative catalysts: An expert review, HZB / TU Berlin, 15 February 2022

Hydrogen hope, DESY (femto), November 2021

Unprecedented view of a single catalyst nanoparticle at work, DESY / ESRF, KIT, 01 October 2021

Green Hydrogen: Focus on the Catalyst Surface, KIT / HI-ERN, 17 August 2021

Zinc oxide: key component for the methanol synthesis reaction over copper catalysts, Fritz-Haber-Institut der Max-Planck-Gesellschaft, 04 March 2021

Three-dimensional View of Catalysts in Action, KIT / PSI, European XFEL et al., 15 December 2020

Hydrochloric acid boosts catalyst activity, DESY / TU München, 07 September 2020

Bespoke Catalysts for Power-to-X, KIT / IMVT, IKFT, 02 July 2020

Catalysts: Efficient hydrogen production via structure, HZB, 02 June 2020