论文部分内容阅读
运用密度泛函理论,对H2O在Yn(n=2-8)团簇表面的分子吸附与解离吸附两种模式进行了结构优化,电子性质分析。结果表明:分子吸附中H2O倾向于O端吸附于Y-Y原子桥位,而解离吸附中H2O解离的H,O原子倾向于吸附于Yn团簇的面位。两种吸附模式都导致了(解离吸附n=4,5除外)主团簇Y原子平均键长增大。分子吸附和解离吸附的吸附强度和化学活性都随尺寸增加而增大。解离吸附中体系的稳定性明显高于分子吸附,且与体系的电子壳层效应密切相关。
Density functional theory (DFT) was used to optimize the structure and electronic properties of H2O on the surface of Yn (n = 2-8) clusters by molecular adsorption and dissociative adsorption. The results show that H2O tends to adsorb O-site to the Y-Y atom bridge in molecular adsorption, and H and O atoms dissociate in H2O tend to adsorb to the surface of Yn cluster. Both modes of adsorption lead to an increase in the average bond length of the Y atom of the primary cluster (except for dissociative adsorption n = 4,5). Adsorption and dissociative adsorption molecular adsorption and chemical activity both increase with size. The stability of the system during dissociative adsorption is obviously higher than that of the molecular adsorption, and it is closely related to the electron shell effect of the system.