Tunneling effect in dissociative adsorption of O2 on Pt(001) surface

Abstract

Dissociative adsorption process of O2 molecule on Pt(001) surface are explored using quantum dynamical calculations based on coupled-channel method. The explored adsorption sites are the direct dissociative adsorption channels, where the molecularly adsorption or precursor state for O2 sticking are absent, with certain amount of activation barrier. We find that the dissociative sticking probability of O2 depicts the sigmoidal (S-shaped) curve in all cases which is a manifestation of the tunneling eŠect. Moreover, the sticking curve is sensitively dependent on the shape of the activation barrier which aŠects the width of the transition region. Finally, the tunneling ěect can be clearly acknowledged from the wave function of O2.