The in-situ analysis of reactive chemical processes is challenging. Molecular beam mass spectrometry is a method to determine the molecular mass of chemical substances (species) that are part of a reactive process. This enables more precise knowledge about the chemical reactions taking place. A gas sample from the reactive medium is transferred into a molecular beam through multi-stage expansion into the high vacuum (10^-7 mbar) which stops (“freezes”) the chemical reactions. Subsequently, mass spectrometric separation of the species takes place. This method can thus provideinsights into the chemistry of a reactive system at different operating points (e.g., at different temperatures).

Besides the determination of the dynamic concentration of chemical substances, e.g., in thermochemical conversion processes, we are interested in the development of mass spectrometric methods (also in combination with other analytical methods) as well as in the detailed determination of the resulting uncertainties. In this context, we cooperate closely with the working group 3.34 "Reaction kinetics".

The working group currently maintains two different time-of-flight (ToF) mass spectrometers, which can be coupled to different reactors.

Information on current research topics can be found here.

The dynamic acquisition/determination of species concentrations in a chemically reactive environment can provide important insights into the ongoing chemistry of a process. At the same time, the data can be used to validate reaction kinetic models. In order to investigate oxidation processes of model fuels, among others, in the temperature range 400-1200 K, the working group maintains a JSR coupled to one of our time-of-flight mass spectrometers via three-stage differential sampling.

The highly diluted reactants are fed into the heatable quartz glass reactor via two separate lines and are premixed shortly before entering the (hot) reaction chamber. Four jets transfer the reaction mixture to the part of the reactor where the reactions take place. These jets ensure homogeneous distribution of the reaction mixture in the reactor.

Information on current research topics can be found here.