关键词: 氢气, 吸附, 解离, 过渡金属, 分子模拟, DFT

Abstract: The adsorption and dissociation mechanism of hydrogen on Fe (1 1 0), Pt (1 1 1) and Ni (1 1 1) surfaces were built based on the density functional theory (DFT) to study different adsorption conformations, dissociation energy barrier as well as electron density changes. DFT calculations indicated that the physical adsorption conformations of H2 on different metal surfaces are different, which may be related to the differences of cell structures and surface structures of different metals. Further calculations on the three metal surfaces showed that the three transition metals have similar catalytic activity on H2 dissociation, with the lowest energy barrier of hydrogen dissociation on Fe (1 1 0). The change of electron density distribution during the dissociation process indicated that H2 has the same electric charge transfer trend on the surface of three metals. It was speculated that H2 dissociation is achieved through the interaction between the d orbital of transition metal and the orbital σ* antibonding orbital of H2.

Key words: hydrogen, adsorption, dissociation, transition metal, molecular simulation, DFT