MILCA - Mechanistic Insights into the Light-induced Carbon Dioxide Activation

• Applicant: Professorin Dr. Stefanie Tschierlei
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 319922640

The proposed project entitled "Mechanistic Insights into the Light-induced Carbon Dioxide Activation" deals with the carbon dioxide utilization by means of visible light provided by the sun. On the one hand carbon dioxide is a greenhouse gas whose increasing emission to the atmosphere is supposed to contribute to global warming. On the other hand carbon dioxide is the C1 building block in natural photosynthesis where the sun energy is stored in form of chemical bonds. Consequently, there is an increasing need to use carbon dioxide as carbon source to generate liquid organic energy carriers like formic acid or methanol as well as gaseous carbon monoxide. Since this transformation is energy intensive it is of high importance to utilize renewable energy sources like visible light to drive the reaction.Moreover, suitable (photo)catalysts and photosensitizers are required to capture the light and to activate the chemically stable carbon dioxide. For this purpose, different mono- and dinuclear catalysts, based on ruthenium bipyridine and other metal porphyrin or corrole complexes, will be applied. To understand the reduction of carbon dioxide and to improve this reaction, the all-embracing knowledge about the catalysts and the underlying mechanism of the light-induced carbon dioxide activation is of particular relevance. Especially, the determination of the catalytic intermediates of the various intra- or intermolecular processes is urgently required. For this purpose, different frequency- and time-resolved techniques like (spectro-)electrochemistry, femto- and nanosecond transient absorption and time-resolved emission spectroscopy will be applied. Thereby, the catalytic intermediates and the light-induced processes of each relevant time scale can be investigated.With this project a detailed picture of the catalytic processes will be gained, including the influence of the protons to the mechanism. Furthermore, the structure-function-properties of the molecular catalysts are characterized, resulting in a deeper insight into the occurring reduction processes. With this knowledge novel concepts for the design of advanced catalytic systems will be developed to improve the activation of carbon dioxid.

• DFG Programme: Research Grants
• Major Instrumentation: Flashphotolyse Spektrometer
• Instrumentation Group: 1120 Spezielle Reaktionsapparaturen (Blitzlicht-, Laser-, Photolyse, Stopped Flow)