高等学校化学学报

高等学校化学学报 ›› 1993, Vol. 14 ›› Issue (4): 540.

• 研究论文 • 上一篇    下一篇

键级守恒法研究甲酸在过渡金属上的分解机理

夏文生, 王南钦, 张乾二   

  1. 厦门大学化学系, 厦门, 361005
  • 收稿日期:1992-04-28 修回日期:1993-01-05 出版日期:1993-04-24 发布日期:1993-04-24
  • 通讯作者: 夏文生
  • 基金资助:

    国家教育委员会博士点基金;国家自然科学基金

Bond Order Conservation Approach to the Mechanism of Decomposition for Formic Acid over Transition Metals

XIA Wen-Sheng, WANG Nan-Qin, ZHANG Qian-Er   

  1. Department of Chemistrg, Xiamen University, Xiamen, 361005
  • Received:1992-04-28 Revised:1993-01-05 Online:1993-04-24 Published:1993-04-24

PDF (PC)

被引次数

4

摘要： 用键级守恒-Morse势方法研究了甲酸在Ag(111)、Ni(111)和Fe/W(110)面上极低覆盖度及较高覆盖度下的分解机理。计算结果表明,在极低覆盖度下甲酸分解通过HCOO中间体进行,其分解能力依Ag<Ni<Fe/W次序增加。Fe/W上HCOO的C—H、C—O键裂活化垒相差不大,且HCOO可氧化表面。覆盖度较高时,Ag上分解机理无变化,而在Ni、Fe/W上甲酸双分于失水形或表面络合物(HCO*HCOO),随后进一步分解。分解能垒在Ni上较低,有可能呈现自催化行为。

关键词: 甲酸分解机理, 键级守恒, 金属表面

Abstract: Bond order conservation-Morse potential approach has been used to study the mechanism of decomposition for HCOOHon Ag(111), Ni(111) and Fe/W(110) surface in the two cases of extremely low and higher coverages.The following results have been obtained; In the first case, HCOOHdecomposed via intermediate (HCOO(s)), which proceeds following the order Ag<Ni<Fe/Weasily, over Fe/W HCOOoxidizes the surface and the bond scission of C-Hand C-Ohas a small energy barrier difference.In the second case, the mechanism does not change over Ag, but changes over Ni,Fe/W.Two HCOOHmolecules form a surface complex (HCO(s) * HCOO(s)) with the loss of water and then decompose further.Over Ni the decomposed reactions have low energy barriers and can show an autocatalytic behavior.

Key words: Mechanism of decomposition for HCOOH, Bond order conservation, Metal surfaces

TrendMD: