Biological/biomimetic solar-driven fuel production
Development of new technologies for CO2-neutral production of non-fossil fuels represents a prime scientific challenge of global importance. In nature, oxygenic photosynthesis facilitates the use of solar energy for formation of energy-rich carbohydrates using merely water and CO2 as raw materials. Key steps are catalyzed by earth-abundant metals at the catalytic site of specialized proteins. Insight in the ingenious bio-catalytic processes in plants, algae and cyanobacteria can promote the development of new technological systems for the light-driven production of non-fossil fuels (solar fuels), in two major ways:
Knowlege-based (genetic) optimization of algae or cyanobacteria for production of molecular hydrogen or other fuels
Use of biological processes as an inspiration or even blueprint for artificial systems (biomimetic approach, artificial photosynthesis)
In the worldwide strive towards new systems for sustainable production of non-fossil fuels, we contribute by both, biophysical investigations on key metalloproteins and by research on new biomimetic catalysts for fully synthetic systems.
1. Light-driven hydrogen production by photosynthetic microorganism
The utilization and production of molecular hydrogen by hydrogenases is investigated in national and international research consortia (H2-design cell, BMBF; SOLAR-H2, European Union; UniCat cluster of excellence in Berlin). Hydrogenases are connected to our research on Photosystem II by a long-term perspective: Solar energy drives the splitting of water (water oxidation, Photosystem II). The obtained 'energized electrons' (reducing equivalents) are used to produce of dihydrogen (reduction of protons, hydrogenases). PD Dr. Haumann and his coworkers at the Physics Dept. of the Free University investigate hydrogenase enzymes by X-ray spectrosocpy, aiming at insight in the determinants of the catalytic Fe-Fe or Ni-Fe site.
2. Synthetic systems for water splitting and H2-formation (biomimetic approach)
Structure-function relations are investigated by X-ray spectroscopy with synchrotron radiation for molecular catalysts in national and international collaborations.Recently, we started to analyze and develop electrodeposited catalysts based on earth-abundant metals. We are aiming at a thorough understanding of the physico-chemistry of a new class of catalyst material. On these grounds, the knowledge-guided search can accelerate the discovery of new catalysts. This research area still is in its infancy. It offers exciting possibilities for discoveries, which could lead to new applications in energy conversion and storage.
National and international networks
Biomimetic and biotechnological approaches are explored in the framework of the UniCat cluster of excellence with groups of three Berlin universities (TU, HU, FU) and other research institutions in Berlin, a joint project of nine German research groups (H2 design cell, funded by the BMBF) and in a consortium of groups from nine European countries (SOLAR-H2, funded by the European Community). Biomimetic compounds are characterized in cooperation with the Swedish Consortium of Artificial Photosynthesis (centered at the Uppsalla University, Dept. of Molecular Biomimetics).