物理化学学报 >> 1988, Vol. 4 >> Issue (06): 624-628.doi: 10.3866/PKU.WHXB19880611

研究论文 上一篇    下一篇

NH3在Ni(111)表面化学吸附的理论研究

郑晓明; 吴钺; 曹培林   

  1. 浙江大学物理系
  • 收稿日期:1987-08-16 修回日期:1988-01-13 发布日期:1988-12-15
  • 通讯作者:

THEORETICAL STUDY OF NH3 CHEMISORBED ON Ni(111) SURFACE

Zheng Xiaoming; Wu Yue; Cao Peilin*   

  1. 浙江大学物理系
  • Received:1987-08-16 Revised:1988-01-13 Published:1988-12-15
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摘要：

本文用X_a-DV方法研究了NH_3和其分解中间体NH在Ni(111)表面的化学吸附及与表面的相互作用, 包括结合能、基态能级、电荷转移、成键特性和总态密度。

Abstract:

The chemisorption of NH_3 on Ni(111) surface has been studied by X_a-DV method. Total energies, ground states, charges transfer and total densities of states are calculated for ontop and three-fold sites respectively, The results show that NH_3 tends to adsorb on on-top site and not to adsorb on three-fold site. The interaction between NH_3 and Ni(111)is mainly due to the mixture of the lone-pair orbital 3a_1 of NH_3 and the 4s orbital of Ni. Charge transfer from bonding orbitals to anti-bonding orbitals causes the activation of NH_3. The interaction between intermediate NH and Ni(111) surface inccluded in our calculations shows that the NH adsorbed on Ni(111) is much stronger than that of NH_3. So that the step NH_(ad)+2H_(ad)→NH_(3ad) needs much more energy on Ni(111) surface than that of on Fe surface. The difficulty of the NH_3 formation on Ni(111) surface is another possibel reason of why Ni is not a good catalyst for NH_3 synthese.