NH3在Ir（211）和Ir（221）表面吸附的第一性原理计算

First-principles calculation of NH3 adsorption on Ir（211） and Ir（221） surfaces

采用密度泛函理论,结合周期性平板模型,研究了NH 3在Ir(211)和Ir(221)表面上的吸附行为.计算结果显示,在Ir(211)、(221)两个面上,NH 3的优势吸附位皆为脊上的top位,吸附能均达到1.0 eV以上,都为化学吸附.电子结构计算结果表明,NH 3通过其N原子的2p z轨道与底物金属Ir的5d z 2轨道混合吸附于表面.

The adsorption behavior of NH 3 on Ir(211)and Ir(221)surfaces was studied by density functional theory and periodic plate model.The calculated results show that the dominant adsorption sites of NH 3 on both the Ir(211)and(221)surfaces are top sites on ridges,and the adsorption energies are above 1.0 eV,which are chemical adsorption.The results of electronic structure calculation show that NH 3 is adsorbed on the surface by mixing the 2p z orbital of its N atom with the 5dz 2 orbital of the substrate metal Ir.