Imaging molecular interaction of NO on Cu(110) with a scanning tunneling microscope
Imaging molecular interaction of NO on Cu(110) with a scanning tunneling microscope
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使用扫描隧道显微镜对 Cu(110) 上 NO 的分子相互作用进行成像
DOI：
10.1002/tcr.201402029
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
H. Okuyama
中科院分区：
文献类型：
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作者：
M. Takase;H. Ajiki;Y. Mizumoto;K. Komeda;M. Nara;H. Nabika;S. Yasuda;H. Ishihara;K. Murakoshi;H. Okuyama
金属表面上的分子相互作用是表面科学的核心问题之一，用于微观理解多相催化。在这篇个人文章中，我回顾了最近关于NO/Cu(110)的研究，利用扫描隧道显微镜（STM）探测和控制表面上的分子-分子相互作用。单个 NO 分子被观察为特征性的哑铃形突起，可视化 2π* 轨道。通过使用 STM 操纵分子间距离，可以控制两个 NO 分子之间 2π* 轨道的重叠。这种相互作用导致分别在费米能级以下和之上形成键合和反键合轨道，作为分子间距离的函数。 2π*轨道也在NO与水分子的反应中发挥作用。水分子向 NO 提供氢键，导致 2π* 能级下移至费米能级以下。这导致电子从底物转移到 NO，削弱并最终断裂 N-O 键。水分子容易发生的键断裂对于环境条件下 NO 的催化还原具有影响。
Molecular interaction on metal surfaces is one of the central issues of surface science for the microscopic understanding of heterogeneous catalysis. In this Personal Account, I review the recent studies on NO/Cu(110) employing a scanning tunneling microscope (STM) to probe and control the molecule–molecule interaction on the surface. An individual NO molecule was observed as a characteristic dumbbell‐shaped protrusion, visualizing the 2π* orbital. By manipulating the intermolecular distance with the STM, the overlap of the 2π* orbital between two NO molecules was controlled. The interaction causes the formation of the bonding and antibonding orbitals below and above the Fermi level, respectively, as a function of the intermolecular distance. The 2π* orbital also plays a role in the reaction of NO with water molecules. A water molecule donates a H‐bond to NO, giving rise to the down‐shift of the 2π* level below the Fermi level. This causes electron transfer from the substrate to NO, weakening, and eventually rupturing, the N–O bond. The facile bond cleavage by water molecules has implications for the catalytic reduction of NO under ambient conditions.