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用基于密度泛函理论的第一性原理方法研究了Cu团簇(Cux,x=1-4)在CeO2(111)表面的吸附.研究发现当团簇比较小时(x=2,3),倾向于平铺表面;当x=4时,Cu团簇在CeO2(111)表面以三维的四面体结构吸附较为稳定,从Cu 3d到Ce 4f的电荷转移使Cu团簇带正电荷.由二维的菱形结构到三维的四面体结构的转变势垒为1.05 eV,并且其中一个Cu原子直接迁移到另外三个Cu原子的空位顶部的转变路径比较有利.在Cu团簇与CeO2的相互作用过程中,Cu-O和Cu-Cu相互作用的竞争最终决定了Cu团簇在CeO2上的形貌.这种CeO2(111)负载的带正电的三维Cu团簇将对水分解,进而对水煤气反应具有高的催化活性.
The adsorption of Cu clusters (Cux, x = 1-4) on the CeO2 (111) surface was investigated by the first-principles method based on density functional theory. The results showed that when the clusters were small (x = 2, Tend to tile the surface. When x = 4, the Cu clusters adsorb on the surface of CeO2 (111) with a three-dimensional tetrahedron structure, and the charge transfer from Cu 3d to Ce 4f positively charges the Cu clusters. The transition barrier between the rhombus structure and the three-dimensional tetrahedral structure is 1.05 eV, and the transition path from one Cu atom to the vacant top of the other three Cu atoms is more favorable.In the interaction between Cu clusters and CeO2 , The competition between Cu-O and Cu-Cu interaction ultimately determines the morphology of Cu clusters on CeO2.The CeO2 (111) supported positively charged three-dimensional Cu clusters will decompose water and then affect the water gas The reaction has high catalytic activity.