H_2O在Cu(111)表面吸附和解离的第一性原理

First-principles study of adsorption and dissociation of H_2O on Cu(111)surface

为了研究H_2O对锂离子电池负极集流体铜表面的影响,采用基于密度泛函理论的第一性原理方法,对H_2O在Cu(111)面的吸附和解离进行了计算。通过Materials Studio软件的Dmol 3模块,计算了相关的几何参数、能垒和态密度等。研究结果表明,H_2O在清洁和预吸附O的Cu(111)表面吸附的最稳定吸附位置都为top位,且H_2O都以分子形态进行吸附。通过态密度分析表明,当H_2O在预吸附O的Cu(111)表面吸附时,O 2p态与Cu 3d态有较强的杂化作用,而在清洁表面则不明显;H_2O在清洁Cu(111)表面解离的能垒为148.54kJ/mol,当在预吸附O原子的Cu(111)表面解离时,能垒明显降低到92.73kJ/mol,表明预吸附O原子能促进H_2O在Cu(111)表面的解离。

In order to study the influence of H2O on the copper current collector for lithiumion batteries, adsorption and dissociation of H2O on Cu（111） surface were calculated by the first-principles calculation method based on the density functional theory. The related geometry, energy barrier, density of states and so on were computed by Dmol3 module of the Materials Studio package. The results indicated that the most stable adsorption sites of H2 O on a clean and a pre-adsorbed O atom Cu（111） are both top sites, and H2O preferred the molecular adsorption. The analysis on the density of states showed that the orbital hybridization between O 2p and Cu 3d states was quite strong for H2 O adsorption on pre-adsorbed O surface, and the hybridization was weak on the clean surface. The energy barrier for H2 O dissociation on the clean Cu（111） surface was 148.54 kJ/mol, while the dissociating energy decreases obviously to 92.73 kJ/mol with the aid of the O atom, which revealed that the pre-adsorbed O atom can promote the dissociation of HzO on Cu（111） surface.