Rotational Effects on the Dissociative Adsorption and Abstraction Dynamics of O2/Al(111)

Focussing on the dynamical aspects of the initial sticking of O 2 /Al(111), we perform quantum dynamical calculations under the influence of an orientationally anisotropic potential energy surface. We discuss the effect of molecular rotation on the O 2 dissociative adsorption. Our calculation results reveal that despite the absence of activation barrier for dissociation with parallel polar orientation, the incoming molecule is reflected from the surface with high probability. For small translational energy, the molecules are trapped by a potential energy dip which exists at a metastable site for dissociation through abstraction, and this is also seen as rotational resonance. We also show that our calculation results agree with the experimentally observed incident angle dependent sticking probability.