Electronic structure and photochemistry of adsorbates on ultra-thin metal films

超薄金属薄膜上吸附物的电子结构和光化学

• 批准号: 09440209
• 负责人: MATSUMOTO Yoshiyasu
• 金额: $ 9.34万
• 依托单位: The Graduate University for Advanced Studies
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440209/
• 关键词: cluster; methane; palladium; silicon; silver; oxygen; photochemistry; photodesorption; 吸着; 光解離; 薄膜; 酸化膜; 吸着状態

We have investigated how electronic structures and photochemistry of adsorbates are modified on nano-structured substance such as ultra-thin films and nano-clusters of metals, in comparison with adsorbates on bulk metal surfaces. We have mainly focused on the following topics :1. Photochemistry of methane on palladium nano-clustersNano-clusters of palladium are formed on A1_<22E2O2<reverse surface chemistry arrow>> prepared on a NiAl(110) surface. The size distribution of clusters can be controlled by temperature of the substrate and the deposition rate of palladium. Methane is adsorbed on the clusters and irradiated by 6.4-eV photons. Methane is photodissociated or photodesorbed as in the case of the clean Pd(111) surface. However, the branching ratio is significantly dependent on the2. Photodesorption of rare gas atoms on silicon surfacesRare gas atoms (Kr, Xe) weakly adsorb on a Si(100) surface. We found for the first time that these adsorbates are desorbed by the irradiation of photons whose wavelength range from near infrared to uv. The excitation mechanism and desorption dynamics have been investigated.3. Unoccupied states of CO adsorbed on Pt(111)The unoccupied state of CO adsorbed on Pt(111) has been monitored by 2-photon photoelectron spectroscopy. We found that this state depends on the adsorption site of CO.4. Photochemistry of oxygen adsorbed on Ag(110)Preliminary measurements have been done on photochemistry of oxygen atoms on Ag(110). The chemisorbed oxygen atoms are removed by uv light irradiation. Wavelength dependence of photo-yield has been measured.In addition, we have found that CO_2 is effectively converted into carbonate species on Si(100) by coadsorption of N_2O and O_2

我们研究了在超薄膜和金属纳米团簇等纳米结构物质上吸附的电子结构和光化学是如何被修饰的，并与体相金属表面的吸附进行了比较。主要研究内容如下：1.甲烷在钯纳米团簇上的光化学研究在NiAl(110)表面制备的Al_2~(2+)和~(22)E_2O_2~(2+)上形成了钯的纳米团簇。团簇的尺寸分布可以通过衬底温度和钯的沉积速率来控制。甲烷被吸附在团簇上，并受到6.4 eV光子的照射。甲烷被光解离或光解吸，就像在干净的Pd(111)表面一样。然而，分枝比显著地依赖于2。稀有气体原子在硅表面的光解吸稀有气体原子(Kr，Xe)在硅(100)表面弱吸附。我们首次发现，这些被吸附的物质在波长范围从近红外到紫外光的光子照射下被解吸。对其激发机理和脱附动力学进行了研究。用双光子光电子能谱研究了CO吸附在铂(111)面上的空态。我们发现，这种状态依赖于CO.4的吸附位置。氧在银(110)面上的光化学研究对氧原子在银(110)面上的光化学进行了初步测量。化学吸附的氧原子通过紫外光照射被除去。此外，我们还发现，通过N_2O和O_2的共吸附，CO_2在Si(100)面上被有效地转化为碳酸盐物种

项目成果

Yoshinobu, J.: "Electronic Structure in the valence region of chemisorbed and physisorbed species on Pd(110)" Journal of Electron Spectroscopy and Related Phenomena. 88-91. 665-669 (1998)

Yoshinobu, J.：“Pd(110) 上化学吸附和物理吸附物质价态区域的电子结构”《电子能谱和相关现象杂志》。

T.Anazawa: "Two-photon photoemission study of CO/Pt(III)" J.Electron Spectrosc.Related Phenom.(印刷中).

T.Anazawa：“CO/Pt(III) 的双光子光电子发射研究”J.Electron Spectrosc.Related Phenom.（出版中）。

Watanabe, K.: "Comparative study of photochemistry of methane on Pt(111)and Pd(111)surfaces" Surface Science. 390. 250-255 (1997)

Watanabe, K.：“Pt(111) 和 Pd(111) 表面上甲烷光化学的比较研究”表面科学。

Watanabe, K.: "Comparative study of photochemistry of methane on Pt(111) and Pd(111) surfaces" Surface Science. 390. 250-255 (1997)

Watanabe, K.：“Pt(111) 和 Pd(111) 表面上甲烷光化学的比较研究”表面科学。

J.Yoshinobu: "Electronic Structure in the valence region of chemisorbed and physisorbed species on Pd (110)" Journal of Electron Spectroscopy and Related Phenomena. 88-91. 665 (1998)

J.Yoshinobu：“Pd (110) 上化学吸附和物理吸附物质价态区域的电子结构”《电子能谱和相关现象杂志》。