Mechanism for NO2 charging on metal supported MgO.
NO2 adsorbed on MgO(100) supported by Ag or Pt is explored by density functional theory calculations. NO2 is weakly adsorbed on MgO(100), with a bond involving minor oxide to adsorbate charge transfer. However, if MgO is supported, then the adsorption energy is considerably enhanced and NO2 is adsorbed as a nitrite (N). Analysis reveals that the NO2 excess charge originates from the oxide side of the oxide/metal interface and that the electron abstraction increases the oxide/metal adhesion. The proposed mechanism is general and should apply for oxidizing surface species.
Grönbeck
Henrik
H
Competence Centre for Catalysis and Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. ghj@fy.chalmers.se