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用DV-X_α方法计算了Ni_3Ti_2O_3,CO-Ni_3Ti_2O_3,CO-Ni_4和CO-Ni_3Ti各原子簇的电子结构。这些原子簇分别模拟担载在Ti_2O_3上的金属Ni,CO在Ti_2O_3担载的Ni表面的化学吸附,CO在纯Ni及Ni_3Ti表面上的化学吸附。比较计算的结果表明,Ti~(3+)离子和金属Ni之间形成强共价键;成键过程中电子由Ni向Ti~(3+)转移,Ni原子带0.07个正电子电荷。计算的Ni-CO键和C—O键的Mulliken重叠集居指出,Ti~(3+)-Ni之间的强成键及电子转移没有导致Ni吸附CO的活性降低及吸附的CO的活化程度的提高。这就表明,电子因素,即Ti~(3+)-Ni之间的强成键及电子转移似乎不是导致所谓的金属载体强相互作用(SMSI)的主要原因。
The electron structures of each cluster of Ni_3Ti_2O_3, CO_Ni_3Ti_2O_3, CO_Ni_4 and CO_Ni_3Ti were calculated by DV-X_α method. These clusters respectively simulate the metal Ni supported on Ti_2O_3, the chemical adsorption of CO on Ni supported on Ti_2O_3, and the chemisorption of CO on pure Ni and Ni_3Ti surfaces. The calculated results show that there is a strong covalent bond between the Ti 3+ ion and the metal Ni, the transition from Ni to Ti 3+ and the Ni atom with 0.07 positron charge. The calculated Mulliken overlap of Ni-CO bonds and C-O bonds suggests that the strong bond and electron transfer between Ti ~ (3 +) - Ni did not lead to the decrease of the activity of Ni adsorbed CO and the activation of adsorbed CO Improve. This shows that the electronic factors, that is, the strong bonds and electron transfer between Ti ~ (3 +) - Ni, do not seem to be the main reason for the so-called metal-supported strong interaction (SMSI).