物理化学学报 >> 1992, Vol. 8 >> Issue (03): 313 -320 .doi: 10.3866/PKU.WHXB19920307

研究论文 上一篇    下一篇

乙腈、苯基氰在Cu(111)与Pd(100)表面上的吸附与反应

冯(言贝)民   

  1. 中国科技大学研究生院，北京 100039
  • 收稿日期:1990-11-29 修回日期:1991-05-27 发布日期:1992-06-15
  • 通讯作者: 冯言贝民

The Adsorption and Reaction of Acetonitrile and Benzonitrile on Cu(111) and Pd(100)

Feng Wei-Min   

  1. Graduate School, USTC,Academica Sinica, Beijing 100039
  • Received:1990-11-29 Revised:1991-05-27 Published:1992-06-15
  • Contact: Feng Wei-Min

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摘要： 用高分辨电子能量损失谱(HREELS~*)对CH_3CN(乙腈)及C_6H_5CN(苯基氰)在清洁与氧覆盖的Cu(111)及Pd(100)表面上的吸附及其反应进行了研究。从198 K时CH_3CN吸附在Cu(111)及Pd(100)表面上的高分辨电子能量损失谱(HREELS)中观察到v(C≡N)几乎消失, 并在195 meV处出现一个较弱的v(C=N)谱带, 表明CH_3CN在吸附过程中C≡N再杂化为C=N,C,N原子分别与金属表面原子键合并C=N平行于表面。从198 K时C_6H_5CN在Pd(100)及Cu(111)上的HREELS表明C_6H_5CN的环平面与CN平行于金属表面。在185K时C_6H_5CN在氧覆盖的Pd(100)表面上的HREELS与其在清洁表面上的相似。并未观察到覆盖氧增强了C_6H_5CN在Pd(100)上的吸附及其它效应。C_6H_5CN吸附在氧覆盖的Cu(111)表面上产生了C_6H_5CNO的特征谱带。

关键词: 高分辨电子能量损失谱, 乙腈, 苯基氰, 吸附, 清洁及氧覆盖的Cu(111)与Pd(100)表面

Abstract: Adsorption and reaction of acetonitrile (CH_3CN) and benzonitrile (C_6H_5CN) on clean and oxygen covered Cu(111) and Pd(100) surface have been studied by HREELS. At 198 K the CH_3CN molecule rehybridized and chemisorbed on Cu(111) and Pd(100) by di-σ-bonds with carbon and nitrogen atom parallelly to the surface. The chemisorbed species, CH_3-C=N, showing a week loss at 196 meV. The HREEL spectra of C_6H_5CN adsorbed on Pd(100) and Cu(111) are indicative of molecularly adsorbed C_6H_5CN, with the ring plane and the CN group parallelled to the surface at 198 K. The preadsorption of oxygen enhancing the adsorption of CH_3CN and C_6H_5CN on Pd(100) surface was not found. The adsorption of C_6H_5CN on oxygen covered Cu(111) surface results in species with a strong mode at 173 meV, suggesting an N-bonded oxide (—C=N=O). Similar reaction with CH_3CN is supposed.

Key words: HREELS, Acetonitrile, Benzonitrile, Adsorption, Clean and oxygen covered Cu(111) and Pd(100)