HPAH · Hydrogen interaction with polycyclic aromatic hydrocarbons – from interstellar catalysis to hydrogen storage

In a truly cross-disciplinary research project encompassing surface science, astrophysics and chemistry we aim to address two of the major outstanding questions in the field of astrochemistry, namely i) how molecular hydrogen, the most abundant molecule in the interstellar medium, form, and ii) whether it is possible to identify specific Polycyclic Aromatic Hydrocarbon (PAH) species in interstellar spectra. The insights gained from the experimental investigations may revolutionize our current understanding of astrochemistry and will have impact even beyond the field. Special emphasis will be placed on the impact our findings will have on ascertaining the suitability of PAHs as a hydrogen storage medium. By combining scanning tunneling microscopy, thermal desorption spectroscopy, laser-induced thermal desorption time-of-flight mass spectrometry, fluorescence spectroscopy experiments and density functional theory calculations we will map out the interaction of atomic hydrogen with PAHs. The goal of the investigation is to obtain atomic level understanding of the atomic hydrogen – PAH interaction in order to i) ascertain whether interstellar molecular hydrogen formation, contrary to present belief but in accordance with our recent calculations, could occur predominantly via interaction with PAHs, ii) measure the adsorption/emission spectrum of Hydrogen-PAH complexes and thereby facilitate observational detection of these complexes in the interstellar medium, iii) determine whether PAHs are a promising medium for hydrogen storage and iv) ascertain whether the hydrogen storage properties of PAHs are tunable by electro-magnetic radiation. This ambitious and cross-disciplinary research project will predominantly take place at the newly established Surface Dynamics Laboratory at the University of Aarhus, headed by the applicant, but will also benefit from fruitful collaborations already initiated with local, national and international colleagues.