Quantum dynamics study on the effects of vibration, translational energy and incident angle on H2 adsorption on a defective Pt(111) surface

© 2014 The Physical Society of Japan. Quantum dynamics calculations via the local reflection matrix method are performed to investigate the effects of the vibration and initial translational energy on the dissociative adsorption of H2 approaching a defective Pt(111) surface at different incident angles and adsorption sites. The sticking probability plot for H2 incident on the top site at 15° shows that as the translational energy is increased, the probability rapidly rises to unity which suggests that H2 is easily adsorbed on the Pt surface. The plot also shows that even though the adsorption process is non-activated, there is a probability that H2 will not be adsorbed on the Pt surface at low translational energies due to quantum mechanical effects. For the rest of the configurations, an S-shaped region is observed in the plots suggesting an activated adsorption process. The plots show that when the initial translational energy (Et) is less that the barrier, H2 sticks to the Pt surface by tunneling through the barrier and when Et is greater than the barrier, H2 sticks on the Pt surface by using its available energy to overcome the barrier. The plots also show significant vibration assisted sticking (VAS) effect for all cases. VAS effect is most prominent for H2 approaching the vacant site at incident angles 15 and 30°