The adsorption of NH3 and NO on the β-MnO2 (1 1 0) surface has been investigated by density functional theory using periodic models. The energetically favourable sites of adsorption of the gases on the β-MnO2 surface are 4-fold coordinate Mn (Mn4-top) and 5-fold coordinate Mn (Mn5-top). The relative adsorption energies (Eads) of these gases on the Mn4-top site and Mn5-top site are in the orders NH3 (Eads = −1.02 eV) > NO (Eads = −0.96 eV) and NH3 (Eads = −0.63 eV) > NO (Eads = −0.49 eV). The N-H and N–O bond lengths, Mulliken charges and the densities of states of the NH3 and NO molecules are discussed after adsorption. The calculated results indicate that the coordination number of surface Mn ions has a significant influence on the adsorption capacity. Furthermore, the analysis of the results of the density of states determinations shows that when NH3 and NO are adsorbed with the NH3-Mn and NO-Mn configurations, the bonding mechanism is mainly from the interaction between the NH3 or NO molecule and the Mn d orbital, which is the major reason for the strong chemical adsorption of NH3 and NO.

中文翻译：

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NH3和NO在β-MnO2 (1 1 0)表面吸附的密度泛函理论研究

NH3 和NO 在β-MnO2 (1 1 0) 表面的吸附已通过密度泛函理论使用周期模型进行了研究。β-MnO2 表面上气体吸附的能量有利位点是 4 倍坐标 Mn（Mn4-top）和 5 倍坐标 Mn（Mn5-top）。这些气体在 Mn4 顶部和 Mn5 顶部的相对吸附能 (Eads) 的顺序为 NH3 (Eads = -1.02 eV) > NO (Eads = -0.96 eV) 和 NH3 (Eads = -0.63 eV ) > 否 (Eads = −0.49 eV)。吸附后讨论了NH和N-O键长、Mulliken电荷以及NH3和NO分子的态密度。计算结果表明，表面Mn离子的配位数对吸附容量有显着影响。此外，