Gas reactor for in situ studies of photocatalysis and energy conversion processes

• Subject Area: Condensed Matter Physics ; Physical Chemistry
• Term: Funded in 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 519099854

The consequences of global warming threaten our daily lives today. Innovative solutions to reduce climate-harming industrial and exhaust gases such as CO2 and CH4 must be found. At the same time, one of the main problems in implementing the energy transition must be solved as quickly as possible: the inability to store renewable energy. A promising approach to solve both issues is the conversion of industrial and waste gases (CO2, CH4, H2, CO) by means of regenerative energy into valuable and transportable fuels (energy-rich hydrocarbons such as methanol CH3OH, ethanol C2H5OH). However, the purely thermal or electrical supply of activation energy does not usually lead to the desired reaction pathways. A promising solution is to additionally control the processes with light or with light and catalysts (photocatalysts). However, at present the fundamental interrelationships of the complex reactions are not yet sufficiently understood and further research is needed.The infrastructure applied for will create the innovative possibility to use Raman spectroscopy established at the IAP (AG Nolte/Ackermann), in particular fs-CARS, to solve open questions in photocatalysis. CARS measurements allow in situ, with high dynamics and spatial resolution, to determine the temperature and concentration of the gases involved simultaneously and thus promise extreme advantages in the detailed study of the intermediate steps in the complex conversion reactions. Therefore, an appropriately adapted gas reactor is to be obtained at the IAP, which, in addition to the measurement of the Raman signal under the actual process conditions (in operando), will simultaneously allow flexible options for the light excitation of different photocatalysts and the gas mixtures.For the quantitative evaluation of the results also in the international comparison it is necessary to extend the equipment, by a standard measuring method for the determination of gas concentrations and conversion rates. The setup is therefore to be equipped with a gas chromatograph in order to determine reaction products with the highest precision.With the aid of the gravitational balance applied for, the sorption of the reaction gases on the photocatalysts can be determined, which is necessary for the comprehensive, quantitative characterization of the substances involved.In particular, the following topics will be addressed:- Development of in situ fs-CARS spectroscopy to study photocatalytic reaction processes.- Chromatographic investigation of these processes as a function of the properties of the excitation light (wavelength, pulse length, pulse frequency, intensity, ...)- Development, fabrication and optimization of highly efficient photocatalysts with controllable selectivity- Simulation of gas-phase based photocatalysis reactions based on the improved data base for mechanistic investigation and optimization of the processes.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Gas-Reaktor für in situ Untersuchungen von Photokatalyse- und Energiekonversionsprozessen
• Instrumentation Group: 1100 Gasentwicklungsgeräte, Vergasungsanlagen
• Applicant Institution: Friedrich-Schiller-Universität Jena
• Leader: Professor Dr. Stefan Nolte