The adsorption and decomposition of formaldehyde and formic acid on the clean and modified Fe(100) surface

Wei Hsiu Hung, Steven L. Bernasek

研究成果: 雜誌貢獻期刊論文同行評審

37 引文 斯高帕斯(Scopus)

摘要

The adsorption and thermal reaction of formaldehyde and formic acid on the clean and modified Fe(100) surface is studied. CH2O adsorbs molecularly on the clean Fe(100) surface without the formation of polymer (CH2O)x (paraformaldehyde) at exposures below 3.0 L. At 223 K, molecularly adsorbed CH2O is hydrogenated to form methoxy and dehydrogenated to form surface CO. Coadsorption of H2O and hydroxy species can oxidize this methoxy species to form formate. Methanol is observed as one of the desorption products for the coadsorption of H2O or OH and CH2O. The presence of adatomic C induces the formation of (CH2O)x polymers on the surface and changes the mechanism of CH2O decomposition. The presence of adatomic O decreases CH2O decomposition and increases molecular CH2O desorption. Oxygen alters the reactivity of the surface but not the reaction pathway for CH2O decomposition. At low exposures, formic acid adsorbs to produce a bidentate formate species on the Fe(100) surface at 100 K. A monodentate formate is observed at high coverage, which converts into a bidentate formate with higher symmetry at 253 K. This surface formate further decomposes to either desorb CO or form O(ad) and C(ad). On the c(2 × 2)-O and p(1 × 2)-OH surfaces, formic acid transfers carboxylic hydrogen to preadsorbed oxygen or hydroxyl to desorb H2O during the thermal decomposition reaction.

原文英語
頁(從 - 到)165-188
頁數24
期刊Surface Science
346
發行號1-3
DOIs
出版狀態已發佈 - 1996 二月 1

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

指紋 深入研究「The adsorption and decomposition of formaldehyde and formic acid on the clean and modified Fe(100) surface」主題。共同形成了獨特的指紋。

引用此