A3: Excitation transfer between molecules in transient atmospheric pressure plasmas and its impact on plasma chemistry
Principal Investigators: A. von Keudell, D. Reiser
Team
![]() von Keudell, Achim (Principal Investigator) |
![]() Reiser, Dirk (Principal Investigator) |
![]() Vervloedt, Steijn (PhD) |
![]() Yu, Siqi (PhD) |
![]() Seferoglu, Fatma-Nur (PhD) |
Description

The internal excitation of molecules and the non-equilibrium population of the degrees of freedom of molecules in a plasma is at the core of plasma chemistry. For example, vibrational excitation lowers activation barriers for electron induced dissociation reactions and determines thereby the energy and conversion efficiency of a plasma chemical process. Metastable states store electronic excitation, which can be transferred to molecules to trigger dissociation. This project aims at a fundamental understanding of the transfer of this excitation depending on the plasma (leading to a specific electron energy distribution function) and the plasma mixture defining the collision partners and thereby the various quenching routes and on the different reactive surfaces. This is evaluated by using Fourier transform infrared absorption (FTIR) spectroscopy for molecules with strong dipole moments such as CO2, CH4, CO, and H2O for lower lying excitation states and threshold ionisation (TI) molecular beam mass spectrometry (MBMS) for higher metastable excitation states. This is combined with an in-situ analysis of the catalytic surfaces using infrared reflection absorption techniques (IRRAS) and spectroscopic ellipsometry (SE). A multi diagnostics set-up will be developed to integrate the various plasma excitation schemes of the CRC 1316 and the different catalytic active surfaces.
Publications
- Plasma and flow simulation of the ion wind in a surface barrier discharge used for gas conversion benchmarked by Schlieren imaging
S. Mohsenimehr, S. Wilczek, T. Mussenbrock, A. von Keudell
Plasma Chem. Plasma Process. 45, 85-112 (2025)
Repository: https://rdpcidat.rub.de/node/990 - Reaction Mechanisms and Plasma-Catalyst Interaction in Plasma-Assisted Oxidation of n-Butane -- A Data-Driven Approach
D. Reiser, A. von Keudell
Plasma Chem. Plasma Process. 44, 867-890 (2024) - Controlled synthesis of NO in an Atmospheric Pressure Plasma by suppressing NO destruction channels by plasma catalysis
S. Yu, S. Vervloedt, A. von Keudell
J. Phys. D: Appl. Phys. 57, 245203 (2024)
Repository: https://rdpcidat.rub.de/node/871 - Ammonia synthesis by plasma catalysis in an atmospheric RF helium plasma
S. Vervloedt, A. von Keudell
Plasma Sources Sci. Technol. 33, 045005 (2024)
Repository: https://rdpcidat.rub.de/node/869 - Impact of the surface on He(23S1) and He2(a3Σu+) metastables densities in atmospheric pressure RF plasma
S. Yu, L. Chauvet, A. von Keudell
Plasma Sources Sci. Technol. 33, 115015 (2024) - Impact of catalysis on n-butane oxidation in an RF atmospheric pressure plasma
C. Stewig, L. Chauvet, A. von Keudell
Plasma Sources Sci. Technol. 10, 105006 (2023)
Repository: https://rdpcidat.rub.de/node/875 - Surface dielectric barrier discharge (sDBD) for flow control in plasma conversion
S. Mohsenimehr, A. von Keudell
Plasma Chem. Plasma Process. 43, 1633-1649 (2023)
Repository: https://rdpcidat.rub.de/node/873 - Oxygen removal from a hydrocarbon containing gas stream by plasma catalysis
T. Urbanietz, C. Stewig, M. Böke, A. von Keudell
Plasma Chem Plasma Process 41, 619 (2021)
Repository: https://rdpcidat.rub.de/node/226 - Dedicated setup to isolate plasma catalysis mechanisms
C. Stewig, T. Urbanietz, L. Chauvet, M. Böke, A. von Keudell
J. Phys. D: Appl. Phys. 54, 134005 (2021)
Repository: https://rdpcidat.rub.de/node/220 - Determining Chemical Reaction Systems in Plasma Catalytic Conversion of Hydrocarbons using Genetic Algorithms
D. Reiser, A. von Keudell, T. Urbanietz
Plasma Chem Plasma Process 41, 793 (2021)
Repository: https://rdpcidat.rub.de/node/317 - Excitation and dissociation of CO2 heavily diluted in noble gas atmospheric pressure plasmas
C. Stewig, S. Schüttler, T. Urbanietz, M. Böke, A. von Keudell
J. Phys. D 53, 125205 (2020) - Non-equilibrium excitation of CO2 in an atmospheric pressure helium plasma jet
T. Urbanietz, M. Böke, V. Schulz-von der Gathen, A. von Keudell
J. Phys. D 51, 345202 (2018)
Thesis
- Christoph Stewig, PhD thesis - 12/2022
Excitation transfer between molecules in transient atmospheric pressure plasmas and its impact on plasma chemistry - Steffen Schüttler, Bachelor thesis - 09/2018
Influence of Catalysts on CO2-Conversion in Non-Equilibrium Atmospheric Pressure Plasmas - Thilo Romba, Bachelor thesis - 09/2018
Calculation of Absorption Spectra of Methane in Non-Equilibrium Atmospheric Pressure Plasmas - Theresa Urbanietz, PhD thesis - 09/2022
Plasma Catalysis during Conversion of Methane/Oxygen/Hydrogen Gas Mixtures - Boris Daniil, Bachelor thesis - 01/2021
Simulation der Nachweisempfindlichkeit eines Atmosphärendruck-Massenspektrometers - Steijn Vervloedt, PhD thesis - ongoing
Plasma catalysis for NH3 formation - Daniel Henze, Bachelor thesis - 09/2022
Measurement of carbon monoxide production in atmospheric pressure plasmas - Siqi Yu, PhD thesis - ongoing
Plasma catalysis for NO formation - Fatma-Nur Seferoglu, PhD thesis - ongoing
Data regression for the plasma chemistry of VOC removal by plasmas - Daniel Henze, PhD thesis - ongoing
Excitation transfer between molecules in transient atmospheric pressure plasmas and its impact on plasma chemistry
Further reading
- Unexpected O and O3 production in the effluent of He/O2 microplasma jets emanating into ambient air
D. Ellerweg, A. von Keudell, J. Benedikt
Plasma Sources Sci. Technol. 21, 034019 (2012)