Innovative Catalyst Platform Advances Understanding of Working Catalysts
© FHI
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.
Unrestrained combinations in composition between active phase and support enable for example direct energy transfer to the reactive interface in electrocatalysis or electrical heating. The physical synthesis methodology within the FHI-HZB CatLab project, taken from solar cell technology, gives access to precise and homogeneous structures and chemistry. This facilitates the mechanistic understanding of working catalysts and their subsequent optimization through interrogating reactive and functional interfaces by operando spectroscopy. The thin film catalysts studied here were synthesized with the objective of designing the interface structure of performance catalysts and closing the material gap between model and real-world powder catalysts while minimizing the use of noble metals. Its unique flat and densely packed structure (LCC) enables to achieve a homogeneous high density of surface active sites, minimizing the content of material present in the “bulk” or subsurface of the active catalysts with benefical effects on the selelctivity of the catalyzed reaction.
This effort is detailed in a study published in Nature Communications, entitled "Rationally Designed Laterally-Condensed-Catalysts Deliver Robust Activity and Selectivity for Ethylene Production in Acetylene Hydrogenation." The study is part of the CatLab Project, a collaboration prominently involving the Fritz Haber Institute of the Max Planck Society (FHI), the Helmholtz-Zentrum Berlin für Materialien und Energie and the Max Planck Institute for Chemical Energy Conversion. The CatLab Project is funded by Federal Ministry of Education and Research (BMBF).
- New instrument at BESSY II: The OÆSE endstation in EMILA 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.
- Green hydrogen: A cage structured material transforms into a performant catalystClathrates 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’.
- Catalysis research with the X-ray microscope at BESSY IIContrary 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.