Modelling of the dissociative adsorption of hydrogen on Pd (111) surfaces by ultra-accelerated quantum chemical molecular dynamics was performed in order to obtain a better understanding of the role of the hydrogen vacancy in the dissociative adsorption of hydrogen. The isolated steps of hydrogen dissociative adsorption on the Pd (111) surface were demonstrated and examined here. The direct observations of dissociative adsorption of hydrogen on the Pd (111) surface (various vacancy models) were successfully simulated. From the analysis of the change of electronic structures and the dynamics of dissociative adsorption process, it was concluded that divacancy sites were inactive for the dissociative adsorption of hydrogen on the Pd (111) surface. The findings suggested that H2 dissociation on Pd (111) required an ensemble of at least three hydrogen vacancies. The results supported the original interpretation of STM work of Mitsui et al. that three or more hydrogen vacancy were required for the dissociative adsorption of hydrogen.

Modeling of Hydrogen Vacancy for Dissociative Adsorption of H2 on Pd (111) Surface by a Quantum Chemical Molecular Dynamics. F.Ahmed, M.K.Alam, R.Miura, A.Suzuki, H.Tsuboi, N.Hatakeyama, A.Endou, H.Takaba, M.Kubo, A.Miyamoto: Catalysis Today, 2011, 164[1], 16-22