The correlation between the inclination of surface reaction sites and the spatial distribution of desorbing product molecules

表面反应位点的倾斜度与解吸产物分子空间分布的相关性

• 批准号: 03640419
• 负责人: MATSUSHIMA Tatsuo
• 金额: $ 1.28万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03640419/
• 关键词: Inclination of reaction site; Spatial distribution of desorption; Carbon nomoxide oxidation; Stepped surface; Platinum surface; 脱離分子の空間分布; CO_2の脱離; 脱離分子の並進速度

1. In this project focused on the inclination of the reaction sites, the spatial distributions of desorbing product CO_2 in the CO oxidation are measured on several stepped platinum surfaces, Pt(110)(1x2)(the inclining angle of terraces : 35.2ﾟ), Ir(110)(1x2)(35.2ﾟ), Pt(112)(19.5ﾟ), Pt(335)(14.4ﾟ) and Pt(557)(9.5ﾟ), to examine how accurately the inclination is preserved in the spatial distributions. The angle has been confirmed to be preserved to about 85% in the spatial distribution. This means that the spatial distribution measurements are powerful to identify reaction sites.2. The CO_2 formation induced by heating the coadlayr of CO and oxygen on the stepped surfaces mentioned above is extended to lower temperatures, with increasing the reaction coverages, yielding several peaks in the range of 150-400 K.The spatial and velocity distributions of each peak have been separately analyzed. The translational temperature of desorbing CO_2 is maximized at the desorption angle where the flux is maximized and decreases quickly with increasing the shift of the angle. This indicates the mechanism in which the spatial distribution is sharpened, i.e., the velocity component of desorbing product is enhanced in the normal direction of the reaction sites.3. The reaction sites are extended from the terraces to steps or into surface troughs when the reactant coverages are increased. The desorption component not collimated in the terrace normal is increased at high coverages.

1.在这个以反应中心倾角为中心的项目中，测量了CO氧化过程中解吸产物CO_2在几个阶梯状铂表面上的空间分布，分别为：Pt110(1x2)(阶地倾角：35.2ﾟ)，Ir(110)(1x2)(35.2ﾟ)，Pt112(19.5ﾟ)，Pt335(14.4ﾟ)和Pt557(9.5ﾟ)，以检验倾斜度在空间分布中保持的准确性。该角度已被证实在空间分布上保持在85%左右。这意味着，空间分布测量对于识别反应地点是强大的。加热上述阶梯表面上的CO和氧的共价层而产生的CO_2，随着反应覆盖度的增加而扩展到更低的温度，在150-400K范围内产生多个峰。脱附CO_2的平移温度在通量最大的脱附角度处达到最大，并随着脱附角度的增大而迅速下降。这表明了其空间分布锐化的机理，即解吸产物在反应部位法线方向的速度分量增强。随着反应物覆盖率的增加，反应中心从梯级延伸到台阶或进入表面凹槽。在高盖度下，未在梯田法线上准直的解吸成分增加。

项目成果

T.Matsushima: "Transformation of Ir(110)(1x1)into(1x2)and spatial distribution of reactive carbon dioxide desorption." Journal of Chemical Physics.94. 704-710 (1991)

T.Matsushima：“Ir(110)(1x1) 到 (1x2) 的转化以及反应性二氧化碳解吸的空间分布。”

Y.Ohno: "Desorption,dissociation and orientation of oxygen admolecules on a reconstructed platinum(110)(1×2)surface studied by thermal desorption and near-edgeX-ray-absorption fine-structure." Japanese Journal of Applied Physics. 32. 383-385 (1993)

Y.Ohno：“通过热解吸和近边缘 X 射线吸收精细结构研究重建铂 (110)(1×2) 表面上氧分子的解吸、解离和取向”，《日本应用物理学杂志》32。 .383-385 (1993)

T.Matsushima: "Velocity distribution of desorbing product in carbon monoxide oxidation on palladium(110)." J.Molecular Catalysis. 72. 169-174 (1992)

T.Matsushima：“钯 (110) 上一氧化碳氧化中解吸产物的速度分布。”

Y.Ohno: "Reaction diagram of carbon monoxide and oxygen on palladium(100) and angular distribution of reactive carbon dioxide desorption." Surface Science. 273. 291-300 (1992)

Y.Ohno：“一氧化碳和氧气在钯（100）上的反应图以及反应性二氧化碳解吸的角分布。”

Y.Ohno: "Orientation of oxygen admolecules on a platinum(110)(1x2) reconstructed surface ; Near-edge X-ray absorption fine structure study." Surface Science. 275. 281-289 (1992)

Y.Ohno：“铂 (110)(1x2) 重建表面上氧分子的取向；近边缘 X 射线吸收精细结构研究。”