Molecular electrochemistry

Prof. Dr. Robert Francke

One focus of the thematic group is the development of electrochemical syntheses of organic compounds. Our extensive equipment and expertise allow us to adapt the experimental setup and the type of reaction control to a variety of different synthetic challenges. Thus, divided and undivided cells are used as required, which can be operated in potentiostatic or galvanostatic mode. If necessary, the preparative work is supplemented by electroanalytical studies, which provide both mechanistic insights and information that is useful for the optimization of reaction parameters. As a further tool, we use homogeneous electrocatalysts (mediators) or catalytically active electrode materials if required. This approach allows both selectivity control and lowering of the kinetic overpotential. To accelerate optimization, screening setups are used that allow up to eight electrolyses to be carried out simultaneously per apparatus. For up-scaling of the reaction, various flow cells are available, which can be coupled with different analytical methods for online product analysis.

Another thematic focus is on catalytically active materials for the electrochemical conversion of small molecules (CO2, H2O, N2, etc.). For the electrochemical characterization of heterogeneous electrocatalysts, several potentiostats with rotating disk electrode (RDE) and impedance spectroscopy are available. We have the possibility to perform photoelectrochemical investigations as well as spectroelectrochemical analyses. Furthermore, new materials can also be tested in a laboratory fuel cell / electrolyzer; the electrode sheets (surface area: 25 cm²) are coated with the active material using the airbrush method. In addition to the classical chemical methods for material synthesis, we have several furnaces for thermal treatments. Particularly for aqueous processes, freeze-drying can be used for treatment of the products.