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

我们研究了与块状金属表面的吸附物相比，纳米结构物质（例如金属的超薄膜和纳米团簇）上吸附物的电子结构和光化学如何改变。我们主要关注以下主题：1．钯纳米团簇上甲烷的光化学在NiAl(110)表面制备的A1_<22E2O2<反向表面化学箭头>>上形成钯纳米团簇。团簇的尺寸分布可以通过基底的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。与干净的 Pd(111) 表面一样，甲烷会发生光解离或光解吸。然而，支化率很大程度上取决于 2。硅表面上稀有气体原子的光解吸稀有气体原子（Kr、Xe）在Si（100）表面上弱吸附。我们首次发现这些吸附物通过波长范围从近红外到紫外的光子照射而解吸。研究了激发机理和解吸动力学。 3． Pt(111)上吸附的CO的未占据状态通过2光子光电子能谱监测了Pt(111)上吸附的CO的未占据状态。我们发现这种状态取决于CO.4的吸附位点。 Ag(110)上吸附氧的光化学对Ag(110)上氧原子的光化学进行了初步测量。通过紫外线照射去除化学吸附的氧原子。测量了光产率的波长依赖性。此外，我们发现通过N_2O和O_2的共吸附，CO_2在Si(100)上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》。