Ralph Krähnert

"Catalysis is the key technology for the transition to renewable energy sources," says Ralph Krähnert. As an Einstein Junior Fellow, the chemist from TU Berlin researched catalysts with precisely adjustable properties. Promising candidates are colloidal metal nanoparticles and porous metal oxides. The aim is to use them to release hydrogen bound in formic acid efficiently and without environmentally harmful by-products. Fuel cells can then convert the hydrogen into clean energy.

»We build efficient detours«

The future of the energy transition is an important driver for my research. I want to be a part of Germany’s commitment to making renewable energies its main energy source in the foreseeable future. This will obviously also help us to reduce our dependence on fossil fuels and electricity imports. One basic problem with renewables is that we rarely need the power that is produced at the precise moment when the sun is shining or the wind is blowing. Energy from solar cells or wind therefore requires a storage structure. One solution is to convert this power into chemical energy, which can then be converted back on demand. In our research group, we develop the catalyst materials that are needed for these conversions. 

Hiking gives us a good analogy when we want to under- stand the effects of a catalyst. In the mountains, hikers often need to choose between a direct path with a few strenu- ous peaks and an alternate route around the mountain that consumes less energy – a smart “detour” if you will. Building these efficient detours is basically how you could describe our work. We try to develop catalyst materials that are more economical, durable, and efficient than the materials we current- ly have. Once I have found an efficient catalyst, I can minimise the energy required for chemical reactions. 

In the coming years, we will be able to employ our catalysts in electrolysers for use in conjunction with wind parks. They will ensure maximal efficiency when converting the electricity generated through wind power into hydrogen for storage. Hydrogen is a clean fuel, but it is hazardous to store and transport. To make it more amenable to handling, we can temporarily bind the hydrogen to fluid hydrocarbons. One of the projects sponsored by the Einstein Foundation within our research group looks at finding a suitable catalyst to convert the chemically bound hydrogen back to pure hydrogen when needed – for use in fuel cells, for example. 

I am a strong advocate of the energy transition, because every single person on the planet will benefit from this change. In the past 100 years, we have consumed most of the available fluid hydrocarbons and emitted carbon dioxide as a result into the atmosphere. If we want to stop the Earth from heating up any further, we need sustainable alternatives to this process. As a scientist, it is extraordinarily exciting to be working on technologies that will have a positive impact on our society.


Interview: Mirco Lomoth

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