Hydrogen adsorption at RuO2(110)

Original · EN

The structural, vibrational, energetic and electronic properties of hydrogen at the stoichiometric RuO2(110) termination are studied using density functional theory. The oxide surface is found to stabilize both molecular and dissociated H2. The most stable configuration in form of hydroxyl groups (monohydrides) at the undercoordinated Oᵇr surface anions is at low temperatures accessed via a molecular state at the undercoordinated Ruᶜus atoms (dihydrogen) and a second precursor in form of a water-like species (dihydride) at the Oᵇr sites. This complex picture of the low-temperature dissociation kinetics of H2 at RuO2(110) is in agreement with existing data from high-resolution energy-loss spectroscopy and temperature programmed desorption. Hydrogen adsorption at Oᵇr sites increases the reactivity of the neighboring Ruᶜus sites, which are believed to be the active sites in catalytic oxidation reactions.