Evidence for oxygen abstraction from NO 2 upon thermal scattering from an Al(111) surface

Evidence is presented for the existence of a non-adiabatic reaction channel, namely the abstraction of an oxygen atom from a nitrogen dioxide molecule upon scattering from an aluminium(111) surface. This reaction channel was studied by exposing the sample to an NO2 molecular beam and subsequently analysing the scattered flux using REMPI spectroscopy. In these experiments, a considerable amount of NO emitted from the surface was detected. The emitted NO has a rotational temperature of ca. 260 K that increases only slowly with surface temperature. In summary, these results provide first evidence for the abstraction reaction NO2(g)→NO(g)+O(a) upon NO2/Al(111) scattering, which may arise when two electrons are rapidly transferred to the incoming molecule while it is unfavourably oriented for concurrent adsorption of both fragments.