Material synthesis and scale-up
Part of the research group at the 56. German Catalysis Meeting 2023 in Weimar
Our goal is to develop technologies to enable chemical energy storage with high efficiency. To achieve this, we conduct fundamental research on heterogeneous catalysis as well as applied engineering research on advanced reactors and systems. The research scope is focused on sustainable catalysis and engineering for a successful energy transition with topics, such as:
- Storage of hydrogen in liquid organic hydrogen carriers (LOHCs),
- Production of sustainable energy carriers,
- Seminal valorisation of carbon dioxide, and
- Sustainable production of synthesis gas.
For that purpose, we study the morphology, surface characteristics and bulk properties of catalysts using classical characterisation techniques (microscopy, spectroscopic and diffraction techniques, elemental analysis, adsorption methods, thermal analysis) to understand the relationship between structure-reactivity and structure-stability in catalysis. Hence, we combine various aspects of catalysis with research in the field of chemical reaction engineering:
- Preparation and design of novel catalysts,
- Sophisticated in situ characterisation under reaction conditions,
- Catalyst deactivation,
- Reaction kinetics,
- Development of model catalysts,
- Synthesis of well-defined (supported) nanoparticles,
- Scale-up of catalyst preparation,
- Reactor and process design,
- Reaction engineering, and
- Thermodynamics of reactions, processes and nanomaterials.
Classical trade-off during catalyst development; ©Moritz Wolf
The focus of our research team is on catalyst development and technologies for chemical energy storage as essential core element of a successful energy transition. In addition, the integration of carbon dioxide in the production of industrial basic chemicals, a crucial component of a circular economy, is investigated. Thus, chemical hydrogen storage for safe and energy-dense transport, the promising valorisation of carbon dioxide and the climate-neutral production of synthetic fuels are part of our field of research. The storage of generated renewable energies with a typically highly fluctuating character in chemical energy storage systems not only allows for medium- and long-term conversion, but also enables the global transport of such harvested energy units from regions with more favourable framework conditions than, for example, Germany. These new technological challenges, just like the sustainable economic production of industrial basic chemicals, can only succeed with new catalyst materials and catalytic processes. Hence, we combine fundamental and applied research to achieve significant improvements in energy storage technologies. This research follows an interdisciplinary approach between catalysis, engineering and material sciences.
Multi-scale and interdisciplinary approach in catalysis research; ©Moritz Wolf
The first step in the development of new catalyst materials is to understand the origin of observed activity, selectivity and stability against multiple mechanisms of catalyst deactivation. However, comparative characterisation of the catalyst before and after its application in a chemical reactor is only meaningful for samples that have the same composition and structure after removal of the reaction atmosphere and are stable under ambient conditions. However, many of the catalytically and economically interesting transition metals are pyrophoric, i.e. they oxidise with strong heat release as soon as they are exposed to ambient air. This high instability prevents the characterisation of such catalysts in the activated state or after their application, which means that only limited conclusions can be drawn about their actual state under reaction conditions. Furthermore, dynamic structural changes occurring during activation or catalysis cannot be traced. However, an understanding of these relationships is essential to understand the link between structure-reactivity and structure-stability. Therefore, investigation of catalysts under reaction conditions, so-called in situ or operando characterisation, is gaining increasing interest. With the insights and knowledge gained, new design catalysts of the future can be developed, which allow the increase of activity, selectivity and stability.