Water dissociation on Cu(111): effects of molecular orientation, rotation, and vibration on reactivity.

Three-dimensional time-dependent quantum mechanical method has been used to study the influence of orientation, rotation, and vibration on the dissociation of water molecule on Cu(111) surface, using London-Eyring-Polanyi-Sato potential energy surface. Our calculations show that dependency of dissociation probability on the initial orientation of the molecule changes with the vibrational state of the molecule. It has also been found that for v(0) = 0 and 1, where v(0) stands for the vibrational state of the pseudo diatomic HO-H, the rotational excitation of the molecule increases the reactivity, whereas for v(0) = 2, the rotational excitation of the molecule decreases the reactivity. Vibrational excitation of the molecule greatly enhances the dissociation probability.